Car parking heater but... with BATTERIES?  :phew: - Page 1
Forum section: electronics / beginners

author: Erwin Ried
author_rank: Regular Contributor
timestamp: October 24, 2020, 02:09:05 pm
content: I have a 2012 hyundai and as you can seewinter is cominghere in norway:Soon I will need to start scraping ice and removing snow every morning... there is a solution> webasto parking heaters but they are 2000 USD or more, plus installation which can be easily another 2000 USD, so I was thinking what if I make a cabin heater with batteries.Is this a crazy idea?Idea:Battery and charger (2 of these to rotate in office and house): 48V 58Ahhttps://www.aliexpress.com/item/1005001316820830.html?spm=a2g0o.productlist.0.0.72bd7fe523NkKB&algo_pvid=cbb6ea52-ec49-4d71-af09-6513921ede3a&algo_expid=cbb6ea52-ec49-4d71-af09-6513921ede3a-4&btsid=0bb0622a16035439498188313ed59e&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_Heater: 48V 800Whttps://s.click.aliexpress.com/e/_99Vqy7PTC heater element (220V or 110V but used at 48V just to keep the batteries warm):https://s.click.aliexpress.com/e/_AcupL5So, remote control via 433. I guess I would need 30 mins per battery of runtime to keep the car over 20C while the environment outside is -10C. The PTC heater element will just be used on idle times.Opinions? Could that work ok?

author: Gyro
author_rank: Super Contributor
timestamp: October 24, 2020, 04:16:30 pm
content: My solution is a 2kW portable fan heater and extension lead. Run it in through a back door and sit it in the middle of the back seat, facing forward. Leave the door on the secondary latch to avoid the cable deforming the rubber seals.It's not the most technically exciting method, but in a hard frost in the UK, it will clear and dry all of the windows and give you a lovely warm interior in the time it takes to eat breakfast (usually leave it just on the 1kW setting). I've been using this method for years.I think you're underestimating the amount of heat you need to produce from that 48V battery supply, probably by an order of magnitude.

author: Stray Electron
author_rank: Super Contributor
timestamp: October 24, 2020, 06:20:00 pm
content: If I read your drawing correctly, you plan to use a 20,000 mAH battery to operate an 800 Watt heater. That works out to 800W/48V = 16+ amps power demand and using a 20 Amp Hour battery you'll only get slightly over one hour of heating. And that's if the battery will even supply 20,000 mAH when operated at that current demand, mostly likely that rate will decrease the battery capacity considerably. Also drawing out more that about 50% of the battery's capacity will shorten the battery's life considerably.Unless you plan on filling the trunk with batteries, you need to use an external AC mains for power.

author: Cerebus
author_rank: Super Contributor
timestamp: October 24, 2020, 06:28:13 pm
content: Quote from: Gyro on October 24, 2020, 04:16:30 pmYou have a point, but it may not be as bad as you think. Your 1kW over breakfast represents, what, 15 min x 1kW = 900 kJ. The 48V 20Ah battery represents 2,880 kJ total stored energy or 900W at a 1C discharge rate. That battery could match your 1 kW heater for 15 min at 1.11 C discharge rate.So far, rough parity. BUT, Norway is not Britain. It getsjust a tad colderover there than over here. I think the first order of business would be to calculate the total heat load that needs to be applied, worst case, in Norway and work from there. One really needs a model of how much metal, glass and frost needs to be heated from what starting temperature to what finishing temperature.

author: Erwin Ried
author_rank: Regular Contributor
timestamp: October 24, 2020, 06:40:09 pm
content: Quote from: Gyro on October 24, 2020, 04:16:30 pmI park outside, and the extension lead would be pretty substantial, 30-40 meters. I would love to permanently install a heater to avoid the seal deformation as you say... if I had a AC outlet near the car.Quote from: Gyro on October 24, 2020, 04:16:30 pmQuote from: Stray Electron on October 24, 2020, 06:20:00 pmAhaha, I think I want 2 backpacks, one while I am in the office, one while I am home and rotate them in that way. I am ok with 30 mins of heat at 800W, just to kickstart the melting and defogging.What I do now is to remove the snow, and then wait 10 minutes inside with the car on idle so everything gets meltedIf I knew before I would tried to find a car with parking heater and steering wheel heating built-in(I had to send my car to the shop and they gave me a rental for couple of days... and the rental had that remote heater... with I had no idea of their existence before moving to norwayQuote from: Cerebus on October 24, 2020, 06:28:13 pmI am happy with:full blast heat at 800W for 10 mins?intermitent heat for 20 mins?survival of the battery for 12-20 hrs with the ptc pad heater

author: Rick Law
author_rank: Super Contributor
timestamp: October 24, 2020, 06:43:22 pm
content: Beware where you aim your heater.This is over two decades ago, but should still apply unless material changed.Deep in Chicago winter, I had a coworker who used a 1.5kw/1.6kw (100/110V) heater (with fan), on extension cord to warm up and de-ice. The heater was on the back seat. However, while the center was aimed and hit the front wind shield, part of the heated air was blowing on the back of the front seats. The vinyl didn't like it... It deformed. If I recalled, it was probably for over 1hr (time enough to eat dinner) but under 2hrs.Car's interior heater is made for the car. If I have to use an external heater, I'd go with much less powerful heater if there is a possibility that you leave it running long.EDIT: adding this:Just in case you wonder how he could plug in the power at the restaurant... We were working there, college jobs back then.

author: Gyro
author_rank: Super Contributor
timestamp: October 24, 2020, 07:01:05 pm
content: Good point Rick.Extended operation would indeed raise the internal temperature excessively, especially when the Ice has melted. My fan heater does have a room thermostat function, but I can't claim to set it sensibly. 10-15 minutes [Edit: just before leaving home,] is about right for defrosted and comfortable, I wouldn't push it further than that!

author: Erwin Ried
author_rank: Regular Contributor
timestamp: October 24, 2020, 07:54:40 pm
content: Based on the answers, now I am thinking I should make 2 units that contain all the components, including the charger:a) infrared thermometer pointing forward to avoid heating surfaces too muchb) ambient cheap humidity /temp sensorc) battery temp sensord) 433 mhz receiver and ESP32While the device is charging, the signal only activates the one which is not charging in that moment (so only 1 remote for both units). Maybe I should get the larger 58 Ah battery, and heat the cabin very slowly.I am thinking the idea is not that crazy. Probably it wont be that bulky either. Just like a heavy lunchbox I place on the seat pointing forward/up

author: Per Hansson
author_rank: Unknown
timestamp: October 25, 2020, 11:53:23 am
content: The most common solution in the Nordics is an electric heater from Defa or Calix.These are usually a heater block for the motor, or (IMO) less preferable a water heater for the cars coolant.And inside the car a regular 230VAC outlet for a heater.Just putting it out there if you did not consider it.A 40m extension cables sounds allot more sane than a battery based heater IMO.P.S: I would never ever trust a cheap lithium battery from China with this kind of load.You are just begging to start a fire with that kind of abuse of a cheap China battery.Also the battery linked in the OP claims to be 58Ah but is really 5.8Ah:"The battery was tested in the lab and not really 59,000 mah is actually 5.9 ah and only lasts between 6-7 km and a disappointing ride!"

author: Renate
author_rank: Super Contributor
timestamp: October 25, 2020, 01:06:20 pm
content: A friend of mine was doing a van conversion and wanted to use electricity (from solar) for general heating.I tried to talk them out of it. People do not appreciate how much energy is required for heat.I have an RV. It has gasoline fuel, propane for heating and cooking and batteries.Besides the truck battery I have two "golf cart" (6 V) batteries that together weigh ~60 kg (~130 lbs).I made a graphic to show the relative energy stored in gasoline, propane and batteries (based on 100% discharge!)Needless to say, I'll stay warm with my propane furnace.

author: Stray Electron
author_rank: Super Contributor
timestamp: October 25, 2020, 04:19:58 pm
content: Quote from: Erwin Ried on October 24, 2020, 06:40:09 pmI don't know if you own your own home and property or not but if It were me, I would run an underground cable out to my parking area and mount an AC outlet as close as practical to my parking spot. Not only could you then use a car interior heater but you could connect an engine block heater, coolant heater and a battery charger or anything else that you desire.OTOH the temperature here is still about 86F during the day so we have very little need for heating.

author: Cerebus
author_rank: Super Contributor
timestamp: October 25, 2020, 04:34:34 pm
content: Quote from: Per Hansson on October 25, 2020, 11:53:23 amIf you live most urban places, a 40m extension cable to roll out into the  street and back in again, in snow, sounds like a pain in the backside to me. Trip hazard, public liability, buried in snow, possibly exposed to cleated footwear - fill in the rest of the list of hazards yourself, I suspect it could get quite long. Sounds like a lot of trouble to me.

author: Mazo
author_rank: Regular Contributor
timestamp: October 25, 2020, 04:58:30 pm
content: I see you wrote that you remove the snow and then sit in the car while the engine is idling.Why so?Most people in my country(far warmer than Norway,but still -20degC a few times per winter and alot of mountainous areas that are norway like),clear a small opening around the driver's door,enter the car,start the engine,turn the heater on max,and proceed to clear the rest of the car.This normally gives the required idle time for the engine to start giving off some heat.Am I missing something?

author: james_s
author_rank: Super Contributor
timestamp: October 25, 2020, 06:31:46 pm
content: Oh man, I feel cold just looking at that photo, brr!When I was still commuting by car I also would occasionally use the portable heater on an extension cord plugged into a timer thing. I ran it in the driver's door so I wouldn't forget and drive off with the cord connected. Made a real difference on the handful of really cold days we get in the winter, but I park in the driveway in front of my house so the cord is not a problem.If you want to use batteries you'll need quite a powerful pack to hold enough energy to warm up a car in that climate. You'll also need to think about recharging those batteries, will you carry the pack into the office when you get to work and charge it there? Otherwise I suppose you could have two packs and charge one in your home each night while the other sits in the car ready to power the heater in the morning.

author: mzzj
author_rank: Super Contributor
timestamp: October 25, 2020, 07:00:21 pm
content: Quote from: Erwin Ried on October 24, 2020, 02:09:05 pmCar shops like to ream you on both webasto prices and installation. (Norway is expensive but for example in here you should be able to get it installed for about 2000 euros total.)Webasto kit is something like 800 euros from Germanyhttps://www.ebay.de/itm/Webasto-Standheizung-Benzin-Thermo-Top-Evo-4-Uni-EBK-MultiControl-Car/292553710120?epid=21030509421&hash=item441d8f5a28:g:aMUAAOSwWTZcasF-Or if you are enough adventurous to install unknown li-ion batteries from Aliexpress you might as well go to chinese webasto/eberspächer copy (bit over 100 euros)https://www.ebay.de/itm/12V-5KW-Diesel-Standheizung-Luftheizung-LCD-Schalldampfer-LKW-PKW-Wohnmobil-NEU/163430807539And that aliexpress battery is a scam as pointed out earlier.

author: Jeroen3
author_rank: Super Contributor
timestamp: October 25, 2020, 07:56:25 pm
content: At work someone put a remote starter unit in his car. Which also works for a frozen window, but probably not to clear a meter of snow.Having a interior preheater installed by professionals can be done for €2k. I do not believe it costs $4k, you shouldn't be asking these things with your brand dealership.

author: Renate
author_rank: Super Contributor
timestamp: October 25, 2020, 08:16:38 pm
content: I've never heard of Webasto, but now we're talking heat! 4-5 kWMy propane furnace is 20,000 BTU/hr, better than 5 kW

author: Erwin Ried
author_rank: Regular Contributor
timestamp: October 25, 2020, 09:11:13 pm
content: Quote from: mzzj on October 25, 2020, 07:00:21 pmWell, the second one is just for diesel. I would install the webasto myself but in one moment I though having a small battery pack would not be a bad idea, a small portable heater instead of few hours cutting into my fuel supply and vents.Quote from: Mazo on October 25, 2020, 04:58:30 pmSnow is good insulator, if snows a lot while you are in the office, the heat of the car will only heat the first layer of the snow and it will take forever to melt everything, I just remove most of the snow and then wait.

author: Erwin Ried
author_rank: Regular Contributor
timestamp: October 25, 2020, 09:12:29 pm
content: Quote from: Per Hansson on October 25, 2020, 11:53:23 amOhhh good catch. That will give less than 10 mins of runtime. I might consider then a 400W heater, since the parts are so cheap it wont be a waste just to assemble a test rig before deciding on webasto or not

author: Erwin Ried
author_rank: Regular Contributor
timestamp: October 25, 2020, 09:14:28 pm
content: Quote from: james_s on October 25, 2020, 06:31:46 pmMy idea is to have 2, with a carrying handle and AC coord attached in a small spool. So I enter the office with one and plug it in, and then back home and plug that other one. There is a button on the pack to trigger the "other" brother to start heating up, so everything is selfcontained.

author: mzzj
author_rank: Super Contributor
timestamp: October 26, 2020, 07:04:33 am
content: Based on my shady memory 1kW Calix or Defa needs 1h even on moderate temperatures like -10c and over 2 hours on -20 to make any difference. My current car has gasoline webasto that heats the car every morning at 07:00You are looking at two 2kWh battery backs at minimum if you want this to really work as intended.

author: mzzj
author_rank: Super Contributor
timestamp: October 26, 2020, 07:15:42 am
content: 1400 euros for one 2kwh battery pack if you go for brand name cells and you get maybe 700 cycles out of it if you are lucky.2 euros per heating ignoring the electricity cost.In comparison 4kW webasto uses 0.5 L/h (diesel) fuel at full blast.30 minutes gives you same 2kWh as above. IIRC gasoline was bit over 1.5 euros/l in Norway = 0.38 euros per heatingLiquified dinosaurs are still damn cheap compared to electricity if you have to use batteries as a storage!

author: Erwin Ried
author_rank: Regular Contributor
timestamp: October 26, 2020, 08:38:44 am
content: I got an answer for the only workshop that brings webasto to my town, it is 35000 kr = 4000 USDCar was 120000 kr 1-2 years ago, so it makes no sense reallyQuote from: mzzj on October 26, 2020, 07:15:42 amTrue... I might need to decide on a chinese webasto clone then...

author: mzzj
author_rank: Super Contributor
timestamp: October 26, 2020, 10:29:48 am
content: Quote from: Erwin Ried on October 26, 2020, 08:38:44 amDamn! But not really surprising, Norway tends to be expensive both on parts and services and up there(Tromso?) you don't have too many options to choose. And in current situation going "shopping" to Sweden or Finland is also pretty much out of question.

author: Renate
author_rank: Super Contributor
timestamp: October 26, 2020, 02:14:39 pm
content: I'm sure that a lot of that cost is installation.To neatly and properly retrofit something in a vehicle takes a lot of time and care.It's something that you could do yourself, maybe not as neatly if you didn't invest the time.

author: Alti
author_rank: Frequent Contributor
timestamp: October 26, 2020, 03:43:51 pm
content: Quote from: Erwin Ried on October 24, 2020, 02:09:05 pmHow about a car cover? I am not sure how much time it takes to put that on/off but with some rubber bands/velcro/ magnets and handles it should not be too hard. Then you can put it into some big watertight bag and keep it in a trunk.

author: Rick Law
author_rank: Super Contributor
timestamp: October 26, 2020, 06:28:14 pm
content: Quote from: Erwin Ried on October 26, 2020, 08:38:44 amSLA may not be a bad option.I use a "jumper-helper" which basically is an SLA packaged for portability equipped with a wall charger and jumper clamp. As it is made for portability, you can easily carry it into the office/house for recharge. Jumper-helper is around $100-$200 USD here depending on capacity and CCA. I can see (not tried, no actual experience) running a 200Watt heater off the build-in cigarette lighter plug of the jumper-helper. Since it has jumper-cable build-in, you can tap that and run at much higher wattage.With that, you also have the added "peace of mind" that if your main car battery is having trouble, you have an extra helping hand at the ready.By the way... In the USA, because of the popularity of the so called "tail gate party", parts for adding an extra battery (wired into your car's wiring and trunk-based mouting) is/was easily available. (Tail gate party is during a ball games, people gathering around the back of the SUV and have a beer party.) I'm not sure about your local market, may be that is also an option for power?

author: Monkeh
author_rank: Super Contributor
timestamp: October 26, 2020, 06:30:29 pm
content: Have you considered a garage or a carport?

author: krebacz
author_rank: Newbie
timestamp: October 26, 2020, 06:46:00 pm
content: I live in Poland and have Eberspacher system in my Skoda Superb (medium size sedan). It uses diesel (0.75/h) from the main car tank and around 100W (glow plug, fan and water pump) from car battery.With -10oC outside and 1-2 cm snow on the car it needs 45 mins for full defrost, 15+ degrees inside.The fuel loss is more than recuperated as the engine starts warm.I paid some 1.7kEUR for the kit plus fitting.I think this is the best way to go - always ready, powerful enough (5kW). The main disadvantage is the load on battery - I've had to replace mine after 4 years.

author: mzzj
author_rank: Super Contributor
timestamp: October 26, 2020, 08:00:38 pm
content: Quote from: Rick Law on October 26, 2020, 06:28:14 pm2kWh needed = You are looking at something like 12v 400Ah battery if you want that the lead acid doesn't die from full dischargeAt least you wont feel cold even if the batteries are empty if you lug around 90kg /200lbs SLA bank every morning and evening

author: Rick Law
author_rank: Super Contributor
timestamp: October 26, 2020, 09:18:31 pm
content: Quote from: mzzj on October 26, 2020, 08:00:38 pmOops - I didn't do the math... I am off by more than a factor of 10.

author: Erwin Ried
author_rank: Regular Contributor
timestamp: October 26, 2020, 09:31:58 pm
content: Quote from: krebacz on October 26, 2020, 06:46:00 pmThat is a very nice price, does it also control the internal fan and blower settings (like defroster direction of the air?). I might need to go shopping it to poland and ask a mechanic to show me an installation. But I need gasoline version, which I think only webasto makes

author: Erwin Ried
author_rank: Regular Contributor
timestamp: October 26, 2020, 09:33:02 pm
content: Quote from: Monkeh on October 26, 2020, 06:30:29 pmNot an option, I park far away in the street.

author: Erwin Ried
author_rank: Regular Contributor
timestamp: October 26, 2020, 09:40:03 pm
content: Quote from: mzzj on October 26, 2020, 08:00:38 pmWhy 2kWh?I think it is different to have the heater unit outside. Now I am thinking on:400W 48V heater:https://www.aliexpress.com/item/1005001407973844.html?spm=a2g0o.productlist.0.0.147292b896L39x&algo_pvid=6dc8d137-7f99-479f-b77a-d0e866eaa110&algo_expid=6dc8d137-7f99-479f-b77a-d0e866eaa110-0&btsid=0bb0600116035440530992119e480d&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_13s6p 48V 20Ah battery:https://www.aliexpress.com/item/4001082734194.html?spm=a2g0o.productlist.0.0.35942438Zrfod8&algo_pvid=58c7b366-6082-4ae3-b90f-19c7adbece0f&algo_expid=58c7b366-6082-4ae3-b90f-19c7adbece0f-2&btsid=0bb0623b16037483277492842ecb4d&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

author: Monkeh
author_rank: Super Contributor
timestamp: October 26, 2020, 10:33:03 pm
content: Eberspächer do indeed offer petrol systems.

author: Per Hansson
author_rank: Unknown
timestamp: October 27, 2020, 04:54:55 am
content: Quote from: Erwin Ried on October 26, 2020, 09:40:03 pmI have used a 1kW 230v electric fan heater in previous cars, as other stated it takes around an hour at -10C to get decent heat, at -20C expect 2 hours.Secondly please understand that ALL batteries sold on Ali Express et all are pure crap, but I will give it the benefit of the doubt:They first state 200000mAh which is 200Ah, but then they also state 20Ah, I calculate a best case 15Ah if they used good 18650 2.5Ah cells, but we all know they don't.So where does the 20Ah number they state come from? Well they state they use 18650 with a 3.4Ah capacity!Please see this battery test linked below for example.It is especially interesting because he tests the batteries at -15C also, and the good ones are really impressive!The China fake capacity batteries do not even work at all at a high load, and add minus degrees to that, yea, I think you can imagine the result...To be able to provide 50A continuous as this seller claims the individual cells must be able to provide 8A.In the Youtube video none of the China branded batteries with grossly overstated capacities where able to do that even at room temperature!

author: mzzj
author_rank: Super Contributor
timestamp: October 27, 2020, 06:41:41 am
content: Quote from: Erwin Ried on October 26, 2020, 09:40:03 pmWhy 2kWh?Because I have been born and living here in the damn freezing north for last 40 years and based on my experience from electric car indoor heaters (Defa/Calix) that's what it takes to melt the car somewhat..(Defa/Calix system is usually installed with both 900...2000W indoor heater and 500...1500W engine block heater)"Liitokala" batteries from Aliexpress are bit better than outright scam: In my experience close to claimed capacity but really suspect cells (unknown chinese manufacturer or used, recycled cells from unknown origin)

author: mzzj
author_rank: Super Contributor
timestamp: October 27, 2020, 06:50:23 am
content: Sensible options are either the 800 euros webasto kit from Germany or installing 230V outlet to your parking place. If living in apartment forget about installing the outlet to parking place.(40 meter extension cords hidden under snow and ice are frowned upon.)2x 48v 20Ah batter backs or 100 Eur webasto copy with external 4l diesel tank might heat your carflaming hot."Chinese webasto" with small diesel tank would be easy option for something that you can keep on eye.

author: james_s
author_rank: Super Contributor
timestamp: October 27, 2020, 06:52:35 am
content: Is there an option of obtaining a used heater from a wrecked car and installing it? Here we still have salvage yards where you can go poke around in cars and pull parts. The prices vary but overall a lot of stuff is quite affordable. I've never seen one of those parking heaters in this country but it's the sort of thing that would probably be $50 or less and a u-pull yard.

author: mzzj
author_rank: Super Contributor
timestamp: October 27, 2020, 07:51:51 am
content: Quote from: james_s on October 27, 2020, 06:52:35 amThere is quite a bit of hoses, wiring and relays sprinkled around the car for the installation, pulling it all out DIY sucks.But ebay.de for example has used ones. Installation is quite hassle even with 100% brand new unit so unless you are really adventurous and want to become Webasto service specialist I wouldn't recommend starting from used unit.

author: Erwin Ried
author_rank: Regular Contributor
timestamp: October 27, 2020, 08:46:23 am
content: Quote from: mzzj on October 27, 2020, 07:51:51 amI agree with used one is not an option. There is too little information about everything related with this and having more unknowns is not good.The 200 USD chinese heater or 800 EUR webasto are perfectly fine options, I dont mind spending an afternoon fitting them, but there is not much information on how to do this on gasoline cars.

author: Renate
author_rank: Super Contributor
timestamp: October 27, 2020, 11:53:09 am
content: Just to add a Nordic (but not Norwegian) spin to this.I previously said that my 60 kg of batteries could deliver 2.7 kWH (theoretically and using 100% discharge).A more reasonable usage would be 50% discharge and 1.35 kWH.A package of Wasa Sourdough knäckebröd delivers 690 kilocalories or 0.8 kWHTwo packages would exceed the energy available from my 60 kg of batteries.There would be a weight savings of 99% = 1 - 2 * 300 g / 60 kg

author: sandalcandal
author_rank: Unknown
timestamp: October 27, 2020, 11:55:29 am
content: Not trying to tell you what to do but be awareLi-ion Batteries + Heat Source = Big DangerAt around 80°C cell materials will start to decompose and release heat, some cells especially under high ambient temperature conditions can go into thermal runaway at this point. At around 120°C most cells start going into thermal runaway under typical conditions. At 150°C "separator shutdown" occurs and if the battery hasn't already it will go nuclear.Lei, B.; Zhao, W.; Ziebert, C.; Uhlmann, N.; Rohde, M.; Seifert, H.J. Experimental Analysis of Thermal Runaway in 18650 Cylindrical Li-Ion Cells Using an Accelerating Rate Calorimeter. Batteries 2017, 3, 14.(paper on thermal runaway onset temperatures)Not to say this project can't be safely done but please be aware of the hazards and take precautions to protect the battery from heat exposure. I'd advise against sitting the batteries anywhere close to the heater and be sure to have tested and verified thermal cut-offs on the BMS work since the risk of over heating here is unusually high.Edit: also consider using a battery chemistry less prone to explosion

author: Erwin Ried
author_rank: Regular Contributor
timestamp: October 27, 2020, 01:44:57 pm
content: Quote from: Renate on October 27, 2020, 11:53:09 amso.. you suggest using knekkebrød as fuel for my heater? I like husman, but maybe havre heats better.

author: Galenbo
author_rank: Super Contributor
timestamp: October 27, 2020, 02:07:48 pm
content: You can choose to look for a Webasto/Eberspacher on the scrapyard.You will pay 100 to 300 euro for a complete system, and 100 euro for some parts to make it new.Most old Vito 112CDI have it.

author: Cerebus
author_rank: Super Contributor
timestamp: October 27, 2020, 04:30:08 pm
content: Quote from: sandalcandal on October 27, 2020, 11:55:29 amWell you'd be crazy to drive around in a vehicle containing at least 475 kWh (1.7 GJ) of energy in the form of a highly volatile, potentially explosive, highly inflammable material, but I do it every time the rather small 50 litre fuel tank in my petrol car is full. What's worse is that it's engineered todeliberatelyproduce a series of mini explosions as the form of propulsion.One has to get the risks into perspective. The energy density of petrol is high (34.2 MJ/l), vehicles contain a lot of it and it is clearly more dangerous than any battery system but we somehow treat this with sanguity. I think the biggest concern, first and foremost, in adding any electrical heating system to a car is avoiding accidental ignition of the vehicle's liquid fuel but this never gets mentioned.You never see anybody saying, a priori: "Petrol + Heat Source = Big Danger". Whereas there's always someone who's going to ignore that and just state (frequently overstate) the risks of adding a fewmegajoulesof battery storage to something that already hasgigajoulesof stored energy on board (or of substituting Lithium energy chemistry for hydrocarbon energy chemistry in the EV case where electricity is the prime mover). Both are dangerousif not used properly, but surely gigajoules outranks megajoules in absolute risk terms. Sure, it would be foolish to ignore the known risks ofanybattery technology, but let's keep things in perspective - a Lithium battery isn't a bomb waiting to go off any more than a car full of petrol already is.

author: mzzj
author_rank: Super Contributor
timestamp: October 27, 2020, 04:33:48 pm
content: Quote from: Erwin Ried on October 27, 2020, 01:44:57 pmknekkebrød with a shoe polish topping was exellent tent stove fuel in Finnish Army when temperature dropped to -40 and firewood was dampAnd army truck "preheaters": keep the trucks running for the whole 2 week arctic exercise.Norwegian twist would be using rancid cod oil... now you can replace that 100kg lead-acid battery with 0.2l can of fish oil

author: Cerebus
author_rank: Super Contributor
timestamp: October 27, 2020, 04:37:45 pm
content: Quote from: Renate on October 27, 2020, 11:53:09 amAll you need is an efficient, safe, lightweight method of converting that potential energy of the knäckebröd into heat. History would seem to teach that the classical way of doing this would be to package a small boy with some machine that requires them to do strenuous work. Perhaps an exercise bike packaged such that it, and the small boy, could be placed across the rear seat of the vehicle. This has the advantage that the small boy could also be equipped with a scrapper and squeegee to complete the clearing of the car after the required amount of heat had been generated. Biological solutions are often more intrinsically satisfying and simple than purely technological ones.

author: mzzj
author_rank: Super Contributor
timestamp: October 27, 2020, 04:48:20 pm
content: Quote from: Cerebus on October 27, 2020, 04:30:08 pmProblem with li-batteries is that they are self-contained system not needing oxygen to burn (and sometimes not even a source of ignition)You can whack 4" nail to gasoline tank and nothing happens. With lithium battery bank the results are lot more spectacular...li-batteries are self-contained energy source like explosives. Difference in energy density between Li-ion and TNT is actually suprisingly small: TNT 4.6MJ/kg, Li-ion 1.1MJ/kg

author: Cerebus
author_rank: Super Contributor
timestamp: October 27, 2020, 04:56:32 pm
content: Quote from: mzzj on October 27, 2020, 04:48:20 pmAll true. It's just that at least once in every conversation on here about Li chemistry batteries and vehicles there's someone goes all Cassandra* about it while ignoring the gigajoule elephant in the room.*Cassandra's prophecies weren'twrong, it's just that she's infamous for spending a lot of time running around crying "woe, woe" to anybody who would listen, and to quite a lot of people who were fed up with hearing it.

author: mzzj
author_rank: Super Contributor
timestamp: October 27, 2020, 05:16:59 pm
content: Quote from: Cerebus on October 27, 2020, 04:30:08 pmOn a second thought your example(and my TNT comparision) ignores the Li-ion combustion energy totally.Tesla S 100d battery contains 100kWh of electrical energyand4 to 10MJ/kg highly combustible material in the cells. Combustion of 100kWh Tesla battery(~600kg) releases more energy than full tank of gasoline! (between 60 to 240 liters of gasoline!)https://ec.europa.eu/jrc/sites/jrcsh/files/claude-chanson_characterize-lithium-batteries-thermal-run-away-reaction.pdf

author: sandalcandal
author_rank: Unknown
timestamp: October 27, 2020, 05:29:37 pm
content: Quote from: Cerebus on October 27, 2020, 04:30:08 pmEnergy capacity has nothing to do with the danger posed here. A block of cheddar cheese has 18MJ/kg,do you think a hot cheesy fondue is dangerous?The danger is the heat sensitive nature of li ion batteries and OPs plan to put them right next to a strong heat source.Autoignition temperature of petrol is 280°C and it requires a source of oxygen to ignite. A combustion engine requires a purpose designed injector/carburettor to aerosolise the fuel in order to have it "explode". Even then, how would sitting an open tub of petrol next to a 800W electric heater enclosed in a passenger compartment be safe? No one's worried about OP igniting his fuel tank in it's sealed tank completely separate from the compartment where the heater is going.Quote from: Cerebus on October 27, 2020, 04:30:08 pmI'm not worried about designed and tested EV systems having their batteries explode as much as I'm not worried about having my car's petrol tank explode. Maybe if I got in a bad crash? but normally, no.The amount of energy present has nothing to do with my safety concerns here. Even if the system in question as was a single 18650 cell, if a single 18650 cell gets exposed to strong heat source then it could explode and burn OP's car down. An 800W heater definitely qualifies as a strong heat source.Another battery tech e.g. SLA or NiMH will bust itself when exposed to heat but will do so in a way much less prone to starting a fire or exploding.Again, not against OP doing what they're doing or Li ion tech in general, pointing out a hazard that no one acknowledged yet.Edit: OP linked a 400W heater not an 800W heater. I got distracted by other people posting their experience with 1kW and 2kW space heaters. Still does pose some potential hazard though and Alibaba cells are less than reliable.

author: Cerebus
author_rank: Super Contributor
timestamp: October 27, 2020, 05:30:31 pm
content: Quote from: mzzj on October 27, 2020, 05:16:59 pmYou've jumped from asmallbattery system to run a heater to a huge 600kg battery designed for prime traction. What was it I said aboutperspective?

author: Cerebus
author_rank: Super Contributor
timestamp: October 27, 2020, 05:49:00 pm
content: Quote from: sandalcandal on October 27, 2020, 05:29:37 pmAnd there's nothing wrong with that. My comment is on the sociology/psychology of it. There's something sensationalist about the way it's presented. Think for a second, who would put a heater where it would raiseanythingto 80ºC in a car. A comment along the lines of "Don't forget to keep the heater and the battery well away from each other, we all know the risks of overheating Li chemistry batteries" would have been proportionate. A headline, in bold, of "Li-ion Batteries + Heat Source = Big Danger"isbeing sensationalist, and every time this comes up someone feels that they need to be sensationalist about it.

author: sandalcandal
author_rank: Unknown
timestamp: October 27, 2020, 05:55:36 pm
content: Quote from: Cerebus on October 27, 2020, 05:49:00 pmI don't know... have you been reading this thread?Edit: I also standby"Li-ion Batteries + Heat Source = Big Danger"in bold is a valid headline to be making in general but particularly considering the Alibaba special Li ion packs OP has been considering. Maybe, I'm just hyper aware of the dangers because I work on li ion safety systems...

author: Cerebus
author_rank: Super Contributor
timestamp: October 27, 2020, 06:02:31 pm
content: Quote from: sandalcandal on October 27, 2020, 05:55:36 pmAh, so you're trying to drum up work!

author: sandalcandal
author_rank: Unknown
timestamp: October 27, 2020, 06:03:51 pm
content: Quote from: Cerebus on October 27, 2020, 06:02:31 pmDRATS I'VE BEEN DISCOVERED!

author: Erwin Ried
author_rank: Regular Contributor
timestamp: October 27, 2020, 08:45:08 pm
content: Quote from: sandalcandal on October 27, 2020, 05:29:37 pmAll the negativity in the thread made me check more info about fuel heaters.Why you think those cells are less reliable? I can check them for a couple of cycles, I added 1 thermal sensor just to keep them on my watch, plus is not a GIANT battery but a lot of small 18650s which, even being dangerous, will not explode like a bomb.

author: sandalcandal
author_rank: Unknown
timestamp: October 27, 2020, 09:12:30 pm
content: Quote from: Erwin Ried on October 27, 2020, 08:45:08 pmPlenty of stories of dodgy cells and cell suppliers if you look around the internet. Even if just one cell goes off, the heat is sufficient to cause neighbouring cells to go into thermal runaway the name for the phenomenon is "thermal runaway propagation" and prevention of it a specific test for EV battery pack certification. Most small pack systems (<1kWh) and ebike systems aren't designed to prevent TR propagation though, cells are just packed right up against each other with no barriershttps://www.eevblog.com/forum/renewable-energy/e-bike-battery-fire/So while being made of a lot of small 18650s can help safety margins the pack as a whole needs to actually be designed exploit the ability to limit failures to smaller energy events.While the pack as a whole is unlikely to explode all at once like a huge bomb, each 18650 cell has enough bang to be dangeroushttps://www.nbcnews.com/health/health-news/battery-behind-dangerous-deadly-e-cigarette-explosions-n1032901(plenty more vape explosion deaths if you want to search) vape explosions are obviously an extreme case but should show you how potentially dangerous these things can be.Use a BMS with thermal cutouts and separate the heater and battery pack I think you'll be fine. It's not like you're going to set this system up and sleep on top of it right? Personal injury at least shouldn't be a problem since no one needs to be in the car while this thing is in use.

author: sandalcandal
author_rank: Unknown
timestamp: October 27, 2020, 09:37:50 pm
content: Under most circumstances, cells will leak, vent, smoke then jet flames. Explosions are obviously something everyone wants to avoid and big companies (LG, Samsung, CATL, Panasonic etc.) design their cells to try avoid explosions with venting and other safety features. The only time explosions tend to occur are when venting features are blocked or the cell is heated so rapidly that it under goes particularly violent thermal runaway which the venting cannot handle. The latter tends to only occur when external heat is applied.

author: mzzj
author_rank: Super Contributor
timestamp: October 27, 2020, 09:45:47 pm
content: Quote from: Erwin Ried on October 27, 2020, 08:45:08 pmEven the big name manufacturers like Sanyo screw up the production sometimes. How well do you expect mystery chinese cell to perform? No known manufacturer, not any sort of traceability. Recycled cells? Cells failed testing in chinese factory? recalled brand-name cells`?https://youtu.be/CUgbmCSmSNYhttps://youtu.be/of01p0Q-yUM?t=96https://eepower.com/news/latest-li-ion-battery-recall-snafu-involves-lenovo-sanyo/IIRC highest risk is during charging. When do you charge the large battery pack.. in your house, during night when you are asleep.

author: Erwin Ried
author_rank: Regular Contributor
timestamp: October 28, 2020, 11:05:06 am
content: Quote from: mzzj on October 27, 2020, 09:45:47 pmIn that case I can add multiple temp sensors and a relay to shutdown everything. If is a real problem.

author: Erwin Ried
author_rank: Regular Contributor
timestamp: October 28, 2020, 11:08:14 am
content: BTW, I see most of the opinions are negative, but I am still interested on evaluating this as a possibility.I got the manual for installing a webasto in my specific car:https://docdro.id/anQarRX<- Thermo Top Evo Parking Heater Installation Documentation Hyundai Veloster.pdf...it is a long process, and quite involved. I can do that too now that I have the guide, but a battery solution still looks charming.

author: Alti
author_rank: Frequent Contributor
timestamp: October 28, 2020, 05:32:46 pm
content: Quote from: Erwin Ried on October 28, 2020, 11:08:14 am1. Put some mains supplied heaters inside,2. Grab a shovel and put some snow and ice on a car3. Connect extender cord through kill-a-watt to mains4. Measure how much energy is needed just to melt the snow and get satisfactory results.I can already tell you this is 334kJ/kg just to melt this white thing.So if you have 10kg of snow on a car, it takes about 1kWh just to melt it.So 1kW heater for 1 hour.Since 90% of that heat is going to escape before it reaches snow, it does not matter if you use 1kW or 2kW, you need 20kW to make this idea practical.

author: Cerebus
author_rank: Super Contributor
timestamp: October 28, 2020, 05:54:21 pm
content: Quote from: Alti on October 28, 2020, 05:32:46 pmSince all that heat is going into a closed, thermally conductive steel box, I'd be curious as to where you think the the 90% is escaping to in such a way that it is not going to reach the snow and ice on the outside of that box.

author: Clear as mud
author_rank: Regular Contributor
timestamp: October 28, 2020, 07:06:39 pm
content: I suggest a mains-poweredradiator-style heater, instead of one that blows hot air that others have suggested. It's safer, just place it so that the hot metal parts don't come in contact anything inside the car.

author: Renate
author_rank: Super Contributor
timestamp: October 28, 2020, 07:37:08 pm
content: If you run a department at work just tell everybody that they are assigned to work inside your car on snow days.The average adult is in the realm of 100 Watts, 6-8 people should do the job.

author: Rick Law
author_rank: Super Contributor
timestamp: October 29, 2020, 03:24:43 am
content: Some additional thoughts:In practice, even if the heater is running off main-AC, one would not walk out to a snow-free car, hop in, and go. In practice, brushing off snow is going to be necessary whenever snow is reasonably heavy.Think about it, if you have say 1/2 meter of snow on your car. Running of main-AC, you can melt all the snow on top (roof), but the heat will have problem reaching your front-hood. So, the windshield may be clear but you will be looking at a mountain of snow on the hood preventing you from seeing the road. So brushing off snow is to be expected regardless of how much energy you got in your batteries. Once you have to brush off snow on the hood, brushing off snow on the car roof is not that much more added difficulty.If I am the user (in the Mid-West USA weather), my concern would be ice. Snow can be brushed off easily. Ice stuck to the windshield is a pain in the behind to remove. So you just need enough heat to ensure that the windshield and other glass-areas are ice free. You would have an easy job of merely brushing off loose snow.But not so fast -- don't forget, as snow melts, the melt will turn into ice almost immediately -- think about the icicles around the roof on your house. Your house probably stay heated all day, but icicles still stick around all day.Therefore, one concern I have would be melted-snow refreezes, and icicle formation. Trying to open the car door with a 5mm (or 1/4 inch) of ice shell covering it is a pain. Now you have a problem a lot worst than what you started with which was mere snow, and that ice covering the lower part of your door probably was the snow that was on the car roof.Since every car design is different, it would be hard to estimate how much heat is required to ensure all the glass around it being ice free, and the doors are not ice-covered. There are so many variables (wind, ambient temperature, amount of snow cover...) over-sizing the capacity will likely be a necessity. And, you need some mean of maintaining that heat till you get into the car -- you don't want to get back to a big icicle.

author: Erwin Ried
author_rank: Regular Contributor
timestamp: October 29, 2020, 09:58:54 am
content: Quote from: Rick Law on October 29, 2020, 03:24:43 amYes. I do not expect to walk into a ice/snow free car ever. Now the situation is:-Dry and no snow = ice, enter to car and turn it on, wait 10-15 mins. Scrape any extra ice (very little). No problem entering to the car, I apply a product to the rubber every 2 months or so that prevents icying there-Fresh snow = easiest to remove, just brush it up and turn the car for 5+ mins just to avoid fogging-Old snow (i.e. after a weekend of not cleaning) = harder to brush, but still not as bad as ice.If the battery heater just preheats the car, it would help. I do not think the fuel option is doable because it is expensive and complicated. Plus my ride to the office is less than 10 mins, so it will need extra work on keeping the battery alive.

author: Renate
author_rank: Super Contributor
timestamp: October 29, 2020, 11:53:10 am
content: What is this "snow" thing everybody keeps talking about?

author: Rick Law
author_rank: Super Contributor
timestamp: October 29, 2020, 06:22:14 pm
content: Quote from: Erwin Ried on October 29, 2020, 09:58:54 amWhen I was living in the mid-west USA, I wish I had an easier way to deal with ice/snow also.We are on the same page. I wish you success on this... Let us (me) know how it works out. I am curious.

author: mzzj
author_rank: Super Contributor
timestamp: October 31, 2020, 09:23:16 pm
content: Quote from: Erwin Ried on October 29, 2020, 09:58:54 am1 kWh estimate that I suggested is just to defrost the windows in -10c weather. Forget about melting layers of snow or heating the car to cozy warm.Car with 2 square meters of windshield and windows in -10c weather would need 400 Watts of power just to keep the windows from freezing if we assume 20W/(m2*K) heat transfer coefficient.Add all the mass and inertia, losses trough doors, roof and floors and you need considerably more. 1kWh in -10cel might not be enough but its reasonably close from what I recall.If you feel that you want to play with the battery idea this might be close to rated capacityhttps://www.aliexpress.com/item/4000987036516.html?spm=a2g0o.productlist.0.0.7b6b6c13Dw7gsl&algo_pvid=b2a5ec17-f1aa-43ef-b279-c342012546ee&algo_expid=b2a5ec17-f1aa-43ef-b279-c342012546ee-17&btsid=0b86d80216041789854396272e22bf&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_Still about 600 euros investment if you buy 4 packs.

author: Erwin Ried
author_rank: Regular Contributor
timestamp: November 01, 2020, 01:10:22 pm
content: I have ordered one cheap 150W 12V heater and I will do some empirical testings with a small 12V battery. I will post the results.

author: Erwin Ried
author_rank: Regular Contributor
timestamp: November 01, 2020, 01:30:55 pm
content: I measured the internal temp vs the external after a short 20 mins ride months ago:In 4-5 hours the internal temperature gets into equilibrium, at least under the conditions of that day.

author: Renate
author_rank: Super Contributor
timestamp: November 01, 2020, 08:08:58 pm
content: One good plot deserves another...I think that I'm snow-free.

author: james_s
author_rank: Super Contributor
timestamp: November 02, 2020, 11:26:46 pm
content: I don't think a 150W heater is going to do much to the temperature inside a car on a sub-freezing day. Space heaters here are an order of magnitude power powerful than that, and in 240V countries they are even more powerful.