Where to buy deep cycle batteries in the US - Page 1
Forum section: electronics / general

author: NiHaoMike
author_rank: Super Contributor
timestamp: April 22, 2012, 03:38:55 am
content: I'm building an alternative energy/backup power system that needs a 12V deep cycle battery, of at least 30AH.* Normally, only the top 10% or so of the SOC would be used as an alternative energy buffer.* More of the SOC (planning up to 50%) can be used for power backup. That condition rarely happens (and usually for only a few seconds when it does, a few times per year), but when it does, I'm planning for up to 60-80A of load (pretty much all electronic stuff) to be operating (worst-case) until the SOC drops enough for some loads to automatically power down or switch to a low power state. At that point, the remaining loads (at most 5A or so) can be easily supported using alternative energy.* Since the battery rarely gets cycled, I would expect old age to be the ultimate failure mode. After reading some IEEE papers, I learned that a very good float charge algorithm for mostly standby use is to supply current until the voltage reaches 14.4V, hold that voltage for a few hours, then supply the load at 12.8V for several days before pulsing 14.4V for a few hours again.* I would prefer a traditional design over a sealed design since it's cheaper and can be serviced to extend its service life.* Is there a definitive reference for the specifications of common brands of deep cycle batteries? I noticed that Walmart sells some cheap ones, but no real specifications were listed. Are they cheap because they're low quality or smaller capacity?* Some places charge a fee if an old battery is not turned in with purchase. Which places generally don't charge a fee or a small fee?

author: IanB
author_rank: Super Contributor
timestamp: April 22, 2012, 04:01:57 am
content: No idea how to answer your questions in detail, but I do believe that deep cycle batteries have marine use and are sometimes called marine batteries. So if you are looking for a source of high quality batteries you might look away from Walmart and towards people who deal with boats and boat hardware. Just throwing that out there...

author: Rerouter
author_rank: Super Contributor
timestamp: April 22, 2012, 04:59:26 am
content: while i cannot say for the us, most marine / camping / 4WD stores have them in aus,as something to look out for if your willing to spend a "chunk" more for reliability and lifetime, have a look at gel cell type deep cycles, discharge rate of only 3% per year normally, and lifetimes in decades,

author: sonicj
author_rank: Frequent Contributor
timestamp: April 22, 2012, 08:34:39 am
content: The problem with flooded batteries for a UPS is with the venting of the electrolyte. The vented hydrogen is highly combustible and the sulfuric acid eats through carpet, concrete, flesh, etc. Most people don't want to deal with that in their houses/workplace.AGM is a ok compromise. They can supply high current and don't make a mess. They don't like to be deeply discharged & don't live all that long.Sealed lead acid is nice because its easy, maintenance free & cheap. They last longer than AGM, but not nearly as long as flooded. Can't supply as high a current as AGM or wet.In the 30AH range @ 12V your best bet is likely a wheelchair battery. I ordered some from a Interstate dealer for $75ea shipped. I forget the specs at the moment....If you decide you want higher capacity & spilling acid is ok, then get a golf cart battery. Trojan, US Batteries, Crown, Deka, Rolls/Surrette, etc.A local golf buggy dealer will certainly have them, wheelchair supply, Sears, Interstate, local speciality battery shop, etc...-sj

author: G7PSK
author_rank: Super Contributor
timestamp: April 22, 2012, 08:58:23 am
content: Not the US I know but these are the people that I go to for batteries for the wife,s wheel chairs and scooters, they have a fair amount of information on their web site and are very helpful to talk to on the phone and by e-mail.http://www.vbat.co.uk/mobility_scooter_batteries.asp?gclid=CJSq-dW1q6sCFYMKfAod7HBn7w

author: T4P
author_rank: Super Contributor
timestamp: April 22, 2012, 09:22:08 am
content: Deep cycle batteries are generally not something you'd want in a UPS , due to electrolyte spillage/hydrogen sulfide venting w/eWhat you really want are those "maintenance free car batteries" which are actually VRLA batteries but are made for cars therefore have the same cranking amps and cheaper in terms of size .Maybe deep cycle VRLA exists ? I don't know .

author: ejeffrey
author_rank: Super Contributor
timestamp: April 22, 2012, 09:51:55 am
content: Any outdoors/marine shop will have deep cycle batteries. Probably even a place like sears. But I would echo the recommendations here against using such a battery indoors without proper venting.

author: G7PSK
author_rank: Super Contributor
timestamp: April 22, 2012, 10:42:58 am
content: Is this what is required-DK12220C SLA - CAR STARTER PACK BATTERYCAR STARTER POWER PACK BATTERY (HIGH CURRENT)PLEASE CHECK THE DIMENSIONS WITH CARE - We urge customers to check the dimensions of the space in which this battery will be fitted with care. CAR STARTER PACKS DO VARY AND THIS MAY NOT FIT INSIDE YOUR STARTER PACKType: Sealed Lead Acid - AGM - CyclicVoltage: 12 VAmp Hrs: 22 Ah (@ 20 Hr Rate)Dimensions: 181 x 77 x 167 mm, (LxWxH) <<< CHECK DIMENSIONSWeight: 6.8 Kg ApproxTerminals: Screw/Bolt DownRechargeable: Yes, typically many hundreds of timesGolf Caddy Rating: 18 HoleUses: Often used on electric golf caddies and small/medium mobility scootersThis range of batteries is specifically designed to handle the demands of highly cyclic (deep discharge) experienced by batteries used on electric bicycles, electric scooters, electric mopeds, powered golf carts and mobility solutions. All batteries conform with ISO9002 and UL and CE Certification. If you have any questions or queries about the batteries most suited to your particular requirement, or you are unable to see your battery of choice, please call us and we will do our best to help you - Telephone 0845 202 00 88.

author: Rerouter
author_rank: Super Contributor
timestamp: April 22, 2012, 11:54:25 am
content: umm.. starter batteries are hopeless for backup charge, medium sized loads over a long period of time will kill them quite quickly, thats why deep cycle batteries are made,

author: G7PSK
author_rank: Super Contributor
timestamp: April 22, 2012, 12:44:56 pm
content: These are deep cycle, they are made for the portable power packs that can also be used for emergency car starting as well as running other equipment.

author: Lightages
author_rank: Unknown
timestamp: April 22, 2012, 02:56:46 pm
content: AGM batteries will tolerate a deeper discharge than any liquid battery. AGMs are probably the best battery to use. They will also usually accept a faster recharge rate than other types. This is nice when you have just gone through an outage and want to be ready ASAP for the next outage.Any battery intended to be used in a car or boat are not good for any kind of prolonged discharge, ie more than 10% for more than an hour or so. They need to be recharged ASAP for them to survive at all.Many deep cycle batteries are really just meant to be discharged a little more than a normal car battery but are not to be used for any kind of repeated long term discharge state.Wheel chair batteries are meant to take a beating and are generally gel cell types, a cousin to the AGM.For the actual charging voltages, do not rely on general information on the battery type you are using. Use the manufacturers information!A good charger is made by a company called IOTA but might be more expensive than you want. Another less expensive alternative:http://www.blackanddecker.com/power-tools/VEC1086BBD.aspx

author: T4P
author_rank: Super Contributor
timestamp: April 22, 2012, 04:21:35 pm
content: you really need a 100 amp hour AGM or gel cell type , they take a beating and trust me when i say you need them 100Ah .Unless you have a panel meter to monitor the discharge ( Like just display the volts there ) gel cell is better .

author: kaz911
author_rank: Super Contributor
timestamp: April 22, 2012, 06:57:27 pm
content: Quote from: Dave.S on April 22, 2012, 04:21:35 pmGEL batteries are not really produced very much any more. They do not live very long and can't take heat. They are fine in 15-35 deg. C. But not so much outside that envelope. Good AGM has a 10-55 deg Celsius operating range. Most solar installations use AGM since they can be charged with Ah/8 amp and can take discharge < 40% without damage. Marine AGM will work if made for general use and not starter use. But for long lasting and abused setup electric truck or golf buggy AGM batteries are best. But usually they are 2 or 6 volt pr. Battery and then a lot in series....Lifeline are one of the best marine batteries. They can be charged at Ah/4..... And their "sister" batteries are from concord for trucks, golf buggy etc.. Rolls Surette are also good batteries... Stay away from Exide and Chinese brands. :-)

author: sonicj
author_rank: Frequent Contributor
timestamp: April 22, 2012, 08:13:25 pm
content: Quote from: NiHaoMike on April 22, 2012, 03:38:55 amthis can be confusing/misleading.... most manufacturers list their Ah capacity at a 20Hr rate (the AH consumed to discharge the battery over 20 hours). this doesn't tell us much as the discharge curve of a lead acid battery is exponential. see:peukert's law.fortunately, the manufacturers usually also provide a "reserve capacity" (time in minutes to discharge battery at 25A) this is sufficient to find the peukert exponent which will allow you to calculate run time for your specific current needs.Quote from: NiHaoMike on April 22, 2012, 03:38:55 amwalmart has the advantage of quantity. they buy in absurd quantities which allows them to purchase at much lower prices than say "Barry's Batteries." walmart's customers expect value; bang for your buck. the chances of walking out of walmart with an exceptional deep cycle battery with a bottom dollar price tag are pretty slim. the chances of you walking out of walmart with a total POS battery are also pretty low.you get what you pay for i suppose... the walmart sales person isn't likely to offer any useful/credible advise on the product in question. the limited selection may or may not fit your specific needs. "barry's batteries" would be able to advise you on the correct battery for your situation, inform you on the differences in quality/reliability and likely have one in stock or can order it in a day or two. smell what im steppin' in?Quote from: NiHaoMike on April 22, 2012, 03:38:55 amthis is a core charge for environmental impact/recycle purposes. would you throw away a $10 bill? this is incentive to keep your 50lbs of lead and acid out of the scrap heap. no way around it aside from trading in a used core.-sj

author: NiHaoMike
author_rank: Super Contributor
timestamp: April 23, 2012, 02:11:01 am
content: After some research, it turns out that pretty much all the "generic" brands are made by a group of 7-8 OEMs. I ended up going with one from Costco, which is a rebranded Johnson Controls. They seem to be the cheapest in my area ($80 or so for a 115AH 12V deep cycle), although they do require a membership fee to buy stuff there. (I already had the membership.)QuoteI knew something was up when I noted that 115AH at 12V translates into 1.38kWh, while a much larger and more sophisticated Prius battery is only 1.4kWh.QuoteGood intentions, although it does become problematic for new applications and doesn't really work when the product the battery is used in goes EOL and ends up being discarded. A few years back, I salvaged a broken UPS from the trash. The UPS was discarded because a MOSFET was bad. I tried replacing it and it just blew again so there is something else wrong, so the board just went into my scrap heap. The two 7AH lead acid batteries in it, however, still had plenty of life left.Ironically, the core charge, while intended to protect the environment, would also create a significant extra expense for large alternative energy setups.QuoteThe room (my lab) is quite well ventilated. The acid is unlikely to spill or leak since the battery doesn't get moved very much and is used very gently, but I will place it in a plastic tray and keep baking soda on hand just in case it does.

author: Lightages
author_rank: Unknown
timestamp: April 23, 2012, 05:16:38 am
content: Quote from: NiHaoMike on April 23, 2012, 02:11:01 amThe gases expelled are dangerous. If you must have a liquid acid battery in a space where there are humans and a chance , any chance of the gases encountering humans or an ignition source, you MUST use a ventilation hood to remove the gases to the outdoors.

author: NiHaoMike
author_rank: Super Contributor
timestamp: April 23, 2012, 01:29:56 pm
content: How is that any different from charging car batteries in a garage? The early EV1s and countless DIY EVs used many lead acid batteries, and there were no issues with charging them in a poorly ventilated garage.And a "sealed" lead acid battery will vent if grossly overcharged

author: Lightages
author_rank: Unknown
timestamp: April 23, 2012, 02:42:09 pm
content: I can't comment on the EV1, as I do not know its battery design. The DIY crowd doing things the same way doesn't necessarily make it safeLiquid acid batteries continuously vent hydrogen and other fumes when they are being charged properly. It is just plain good sense to not have them charging inside a house.Yes, sealed battery types can vent if overcharged but it is not their usual mode of operation.

author: T4P
author_rank: Super Contributor
timestamp: April 23, 2012, 03:47:54 pm
content: And it's pretty rare that you can overcharge AGM's to the point of venting .But during the charging process the flooded cells vent constantly and all it takes is a small lighter flame to magically brighten the place up (READ: EXPLODE!)

author: G7PSK
author_rank: Super Contributor
timestamp: April 23, 2012, 05:46:48 pm
content: The best batteries that I have come across for deep cycle use over long time periods are BP.solar I installed a set of these in 2000 and they are still going strong the only problem has been connections coming loose due to lead flowing on the posts from pressure cycles due to expansion and contraction of stainless steel bolts. The batteries are charged in the main by a bergy wind turbine with a ten KVA propane powered alternator set which is started by the inverter when cell volts fall too low or demand exceeds a pre-set level.These are 900 amp hour.

author: Time
author_rank: Frequent Contributor
timestamp: April 23, 2012, 05:53:16 pm
content: I have experience designing huge battery systems (100+) for strange applications. I have found the guys athttp://www.batterysystems.net/have been helpful with finding me the right batteries for the right applications.

author: sonicj
author_rank: Frequent Contributor
timestamp: April 26, 2012, 11:01:16 pm
content: Quote from: NiHaoMike on April 23, 2012, 01:29:56 pmArticle 625.29 of the NECaddresses ventilation requirements for indoor charging of EVs with vented batteries. I doubt that there are many LA EV owners that charge in poorly ventilated garages... I suspect most have the wits to know to at least crack a door/window and maybe even turn on a fan.a proper charge routine for flooded LA batteries includes a final phase where the cells are deliberately "overcharged." this is to help with stratification of the electrolyte as well as balancing of the cells. during this phase, the water separates into in oxygen and hydrogen and increases pressure within the cell which is allowed to vent through the valves in the caps. even though the caps are designed to allow only gas to escape, some electrolyte loss is inevitable. this out-gassing/recombining process continues (at a lower rate) even after then equalization charge is over and float voltage is applied.personally, i only bring AGMs and SLA inside the house... flooded cells are messy and sulfuric acid is nasty stuff. my 2¢ fwiw.-sj

author: bombledmonk
author_rank: Regular Contributor
timestamp: April 26, 2012, 11:21:05 pm
content: Enersysbatteries are used for Teleco backups and in both very hot and very cold hi-rel environments. I doubt you'd go for them ($$$$), but they at least used to have some good app notes on the web about lead acid batteries. I can't find them on their website currently, but google may be of assistance for their charging ANs.

author: sonicj
author_rank: Frequent Contributor
timestamp: April 26, 2012, 11:21:58 pm
content: Quote from: G7PSK on April 23, 2012, 05:46:48 pmare you sure its the expansion/contraction of the bolts? time + temperature + pressure = creepi have the same problem on my golf cart... i have to snug up the connections every so often. i've been meaning to experiment with wave, belleville, & spring washers to combat creep.those are sweet looking cells! i dig the clear cases! it would be interesting to hang a desulfator on one of the cells for a month or two with a time lapse camera to see what (if anything) happens!-sj

author: G7PSK
author_rank: Super Contributor
timestamp: April 27, 2012, 07:31:55 am
content: Yes I am sure that the connections slacken due to creep if you look at the posts carefully (you cant see them in the photo as they are covered by the yellow plastic bus covers) the edges which were flat are now bulging somewhat. The main problem with these shape of cell is stratification and even a long equalization charge does not mix them properly. Every now and then they need to be taken out and tipped over a few times to achieve mixing. It is also a good idea to wash them out and replace the electrolyte with fresh.

author: AlphZeta
author_rank: Regular Contributor
timestamp: April 27, 2012, 04:51:13 pm
content: Not sure if you got your answers, but I have been usinghttp://www.atbatt.com/and it seems that they have a large selection of different kinds of batteries. Shipping is also very reasonable.