Ohm super capacitor car battery - Page 1
Forum section: electronics / general

author: resistor
author_rank: Regular Contributor
timestamp: August 20, 2015, 02:35:10 am
content: https://www.indiegogo.com/projects/ohm-a-smarter-car-batteryA 6 lbs. car battery built on super caps and lithium batteries. Thoughts?

author: Mr.B
author_rank: Unknown
timestamp: August 20, 2015, 02:55:33 am
content: Certainly looks a lot more feasible than Batteriser...I am not sure how it would perform in cars like mine (Mazda CX-5) where the engine is shut down at particular idle times, such as waiting at traffic lights.A typical drive to work, only a short distance, would see my car stopped and started about three times.I guess the super caps are recovered very quickly by the car alternator so the behaviour of my car may not make any difference.Anyway, worth keeping an eye on the project.Thanks for sharing.

author: helius
author_rank: Super Contributor
timestamp: August 20, 2015, 03:10:00 am
content: What is the rationale for including the supercaps? I don't see the point at all.Car battery boosters that are even smaller and lighter (and much cheaper) than that have been reviewed here before:https://www.eevblog.com/forum/reviews/easyjumper(tm)-multi-function-portable-car-jump-starter

author: tautech
author_rank: Super Contributor
timestamp: August 20, 2015, 03:43:46 am
content: Member Psi runs supercaps in his car:https://www.eevblog.com/forum/beginners/supercapacitor-circuit-design-help-please!/More discussion:https://www.eevblog.com/forum/beginners/super-cap-risk-assessment/https://www.eevblog.com/forum/projects/lithium-ion-car-starter-packs/msg625397/#msg625397

author: TheElectricChicken
author_rank: Frequent Contributor
timestamp: August 20, 2015, 06:47:54 am
content: Everything is already off the shelf available, low battery cut-offs and so forth. One big problem is the storage capacity. 10Ah capacity. How does that compare to a regular battery ? CRAPThere are instances where you need alot more cranking done to start the car. Like running out of fuel, then making sure it is fuel you ran out of (by too much cranking) then once you get fuel, cranking it a lot more. I doubt that this product will do it, and not for the cost of an auxiliary battery setup which has been around for 100 years or so.

author: romelec
author_rank: Contributor
timestamp: August 20, 2015, 06:10:00 pm
content: On thebattery sizepage there are links to battery requirements for a lot of brands.For example a Lexus GX470 is compatible with their "large" model need a CCA of 710.Quote from:[url=http://www.autobatteries.com]www.autobatteries.comFor 30 seconds the supercap is useless, so the 10Ah cells should be able to deliver the 700A, so a 70C discharge rate.This is impossible, the peak discharge for this kind of battery (headway 38120S for example) is generally 10C with reduced life time if repeated frequently.And the Peak CCA given in the indiegogo page is 500A...

author: Refrigerator
author_rank: Super Contributor
timestamp: August 20, 2015, 06:46:37 pm
content: I guess people that need to crank their engines frequently can keep their lead-acid batteries, but newer, more efficient cars with smaller, easier to crank engines could use this.We really need more people innovating and bringing new tech to the mainstream.

author: mikerj
author_rank: Super Contributor
timestamp: August 20, 2015, 08:10:48 pm
content: How is the low voltage disconnect implemented? A bunch of big MOSFETs?

author: TheElectricChicken
author_rank: Frequent Contributor
timestamp: August 21, 2015, 04:14:14 am
content: Quote from: Refrigerator on August 20, 2015, 06:46:37 pmTrue about innovation, but people are going to run out of fuel and use headlights with the engine off now and then. The product gives less than the current off the shelf items.

author: daveatol
author_rank: Regular Contributor
timestamp: August 21, 2015, 06:52:35 am
content: Quote from: mikerj on August 20, 2015, 08:10:48 pmIt probably justs stops topping up the ultracaps from the lithium batteries. I assume the caps connect directly to the device output terminals.

author: Circlotron
author_rank: Super Contributor
timestamp: September 13, 2015, 01:05:37 pm
content: Quote from: tautech on August 20, 2015, 03:43:46 amMe too.https://www.eevblog.com/forum/chat/what-did-you-buy-today-post-your-latest-purchase!/msg705733/#msg705733Stupid URL is too long and wraps. Anyway it's reply #194 on what-did-you-buy-today-post-your-latest-purchasehttp://pcmhacking.net/forums/viewtopic.php?f=13&t=4274

author: mos6502
author_rank: Frequent Contributor
timestamp: September 13, 2015, 11:04:54 pm
content: Let's say your car broke down on the freeway, you turn on your hazard lights ... well, "Ohm" is smart, after a few minutes it cuts the power, leaving you in the dark for a semi to plow into you.

author: Circlotron
author_rank: Super Contributor
timestamp: September 14, 2015, 12:17:09 pm
content: ^^ Not me. I have the ultracaps in parallel with the normal car battery, so best of both worlds.

author: free_electron
author_rank: Super Contributor
timestamp: September 14, 2015, 02:27:06 pm
content: "Remember to connect the positive/red lead first to reduce the risk of sparking."and they design batteries ? we need a run-for-the-hills icon ...

author: AF6LJ
author_rank: Unknown
timestamp: September 14, 2015, 02:42:19 pm
content: Quote from: free_electron on September 14, 2015, 02:27:06 pmActually that is accepted practice, and here is why.You disconnect the negative terminal first so that when you are disconnecting the positive terminal contact with any metal objects in the vehicle do not cause sparks.When installing a battery the reverse is done the negative terminal is connected last so that any contact between the battery terminal and the vehicle by a wrench doesn't cause a spark.Now this only applies to negative ground systems.For positive ground systems the reverse is true.The grounded lead comes off first and goes on last.

author: AF6LJ
author_rank: Unknown
timestamp: September 14, 2015, 02:45:21 pm
content: This is not going to work for everyone;I could see this being used on a Smart Car where the electrical power demand is low.Is this going to work for the guy down the street with the Chevy all tricked out with the 2600W sound system, or my friend with enough radio gear to operate from 1.8 to 440MHZ and an ARPS radio....Hell NO.

author: free_electron
author_rank: Super Contributor
timestamp: September 14, 2015, 03:13:15 pm
content: Quote from: AF6LJ on September 14, 2015, 02:42:19 pmEver thought about using isolated tools ? rubber has been invented over 1000 years ago ...

author: AF6LJ
author_rank: Unknown
timestamp: September 14, 2015, 03:30:42 pm
content: Quote from: free_electron on September 14, 2015, 03:13:15 pmGas and oil attack rubber, besides why bother when a little common sense is so much cheaper.

author: Icarus
author_rank: Regular Contributor
timestamp: September 14, 2015, 04:28:54 pm
content: I don't wanna ruin it but modern cars (after 2000) have alrealy battery drain prevention systemFor Instance, I've a VW Passat(2000) and It doesn't matter whether I left the head light On or Off.

author: Delta
author_rank: Super Contributor
timestamp: September 15, 2015, 09:18:45 am
content: Quote from: free_electron on September 14, 2015, 03:13:15 pmTranslation: Oh, I've never changed a car battery so I didn't realise that, but rather than admit to such I'll mumble about using insulated tools... 😂

author: tautech
author_rank: Super Contributor
timestamp: September 15, 2015, 09:40:14 am
content: Quote from: Delta on September 15, 2015, 09:18:45 amDespite FEs view, negative disconnection first and reconnection last has been industry safe practice for many decades and even those that have done their own auto DIY have learnt this the hard way.

author: AF6LJ
author_rank: Unknown
timestamp: September 15, 2015, 12:56:46 pm
content: Quote from: Delta on September 15, 2015, 09:18:45 amGrowing up all the females in my family learned such life skills as changing oil, replacing an air filter, and what to do with an overheating car among others.

author: mos6502
author_rank: Frequent Contributor
timestamp: September 15, 2015, 06:53:05 pm
content: Quote from: tautech on September 15, 2015, 09:40:14 amAh, yes. Touching the aluminum intake manifold with your ratchet while unscrewing the positive battery terminal is an experience you're unlikely to forget. And then you'll know why to detach the negative terminal first.I still have that ratchet with the melted spot somewhere ...

author: Deathwish
author_rank: Unknown
timestamp: September 15, 2015, 07:04:05 pm
content: Quote from: AF6LJ on September 14, 2015, 02:42:19 pmAs someone who has City and guilds in motor mechanics that is spot on and how I was taught on the course, its the same principles when welders crack open oxy / acetylene bottle valves and light the acetylene first I believe