This question may have already been asked. If it has I could'nt find the thread. Does anyone know how long a car battry will last on the shelf? I'm thinking that if I had a couple of new car batteries I could use them as an electrical source. Anyone have any ideas?

Thanks

-- Concerned (anon.@anon.com), February 18, 1999

Answers

You're far better off buying dunlop golf cart batteries at Sams, $43 each.

-- Buffalo Bob (buff@hal.com), February 18, 1999.

I don't know if they are still available, but at one time you could purchase batteries "dry-charged". They didn't have the electrolyte put in till you bought them, then they poured in the proper amount of sulphuric acid. The acid was kept in bulk by the battery retailer. It came in relatively small containers (1 gallon I think, maybe 5), and could be purchased by an individual at some automotive supply stores.

Batteries will slowly discharge sitting "on a shelf" for a period of time, but keeping them hooked up to a trickle charger will take care of that. I still think the dry-charged way would be the best, though.

-- Gerald R. Cox (grcox@internetwork.net), February 18, 1999.

I am the furthest thing from an energy (electric or otherwise) expert. With that being said, car batteries are batteries that are/were developed for high, very short surge periods (eg. starting your car) and are not appropriate for low volume long duration electric needs such as lighting, TV/VCR etc. I believe you need batteries called DEEP CYCLE which are intended for this very use. Someone please feel free to correct me if I am wrong. Good luck.

-- choo choo (re@search.com), February 18, 1999.

You do not want to use car batteries. Repeated deep discharge will kill them quickly. Use deep cycle batteries.

-- Scotty (BLehman202@aol.com), February 18, 1999.

marine batteries, meant to be used on fishing boats for electric trolling motors, are "deep cycle" batteries. I suspect the golf cart batteries mentioned above are also.

-- Jon Williamson (pssomerville@sprintmail.com), February 18, 1999.

My setup

2, 53 watt, 5 amp solar panels

2 deep cycle, 12 volt batteries

Solsum charge controller, with discharge protection, overcharge protection, temperature compensation and gassing regulation. Also have a second identical unit as a backup (they were cheap - $30 each).

I live in South Florida, so even in January we get plenty of sun. I am by no means an expert on this, and any suggestions anyone has is more then welcome. I'm waiting on a book from Amazon that I expect will help me out with optimizing this system. I plan to run small flourescent light(s) and radios/scanners/lcd tv. I discovered a world of 12 volt items at my local RV store, and may add a few things. Was without power for several days after hurricane Andrew, and woulda given my left...umm.. pinkie finger for a fan..lol.

Would I be better off running the batteries together, or alternating them?

-- Online2Much (low_voltage@the.turn), February 18, 1999.

Online2Much, what book are you getting from Amazon, and can you recommend any with practical info on solar energy for Floridians? Thanks.

Jeannie

-- jhollander (hollander@ij.net), February 18, 1999.

Best to hook the batteries together in parallel, Online, without switching them out. They will age at a similar rate that way, and you won't discharge any one battery too deeply. With your two panels, you'll probably want them charging a battery bank of about 200 to 300 ampere/hours - no more. If your batteries are the deep-cycle/marine variety, in either the size 24 or size 27F cases, they probably aren't true deep-cycle, but will still give good service as long as you discharge them no more than 20% or so. Golf=cart batteries are better for deep-discharge, but with lots of sun the others will do fine. BTW, bet you get a lot of lightning down there in FLA - make sure the panels/controller/batteries are grounded, and it's not a bad idea to disconnect the batteries from the panels when a storm comes along. A direct strike could rupture the cases, spewing acid all over the place.

Hope this helps.

-- Why2K? (who@knows.com), February 18, 1999.

You should definitely use the deep cycle batteries, and not the car batteries. Maybe in an extreme emergency, you might get away with it, but I wouldn't.

I have heard that you can get the batteries shipped w/out acid added. I have also heard that if you pump nitrogen into the empty cells, and seal it up with something airtight, you can store the battery for a long time. Apparently, the lead oxidizes or something similar, and after you add the acid, the battery life is much shorter than it ought to be.

Can anyone confirm my last paragraph either way?

I used a large Ni-Cad battery bank, so I'm set.

-- Bill (billclo@hotmail.com), February 19, 1999.

We just bought a deep cycle battery and sump pump motor at Home Depot. The battery was packed dry with acid to add when ready to use.

Me.

-- Floyd Baker (fbaker@wzrd.com), February 19, 1999.

Car batteries are your last choice...they will be very short lived which is not only not cost effective but also more likely to leave you in the dark. The "marine Deep Cycle" batts are a poor choice as well being very similar to the car types (sponge lead plates) as opposed to something like golf cart batts (should be your minimum choice) which use sheet lead plates and will last far longer.

Lots of info at our website I think you'll find useful, http:// www.homepower.com

Regards...DCK Home Power Magazine

-- Don Kulha (dkulha@vom.com), August 18, 1999.