# How long can I expect lead acid batteries to last?



## JRP3 (Mar 7, 2008)

It really depends on how you use and take care of them. Lots of variables. They could last 5 years or you could kill them in 2.


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## Greenflight (Sep 13, 2007)

Yeah, 3-5 years seems about standard. You do have to keep up with the maintenance, though.


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## CPLTECH (Sep 14, 2007)

From personal experience:
This past year, I’ve put 3K miles on a set of US Battery 145’s which are the 250 AH 6V units similar to Trojan’s T-145. They seem to be same as when installed. The trips (8-30 mi) average 35AH to 100AH before recharge and have yet to add water. MrSharkey said I was not charging it sufficient, so after that I made sure I put in 120% of whatever I took out. After that the batt perked up. Just bought a hydrometer but have yet to use it.
Personally, I expect the life to be better (1) large capacity cells (2) have yet to discharge below 50% DOD (3) avoid amps above 300 so as not to warp plates. Hope to get 3 yr/10K miles at a minimum. Do the math, the pack cost $2200. 
Like the previous post, I wonder how long the small batteries will last under high amp loads. Like the tortoise & the hare, I may be slow and heavy… Let’s see who endures to the finish line. 

EV owners are definitely a breed of their own. EV’s are not for everyone. Me, I sit on the fence trying to justify the co$t. Now if I could generate my own power, I’d be a lot happier not connected to the pump.


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## the slashmaster (Feb 24, 2008)

CPLTECH said:


> From personal experience:
> This past year, I’ve put 3K miles on a set of US Battery 145’s which are the 250 AH 6V units similar to Trojan’s T-145. They seem to be same as when installed. The trips (8-30 mi) average 35AH to 100AH before recharge and have yet to add water. MrSharkey said I was not charging it sufficient, so after that I made sure I put in 120% of whatever I took out. After that the batt perked up. Just bought a hydrometer but have yet to use it.
> Personally, I expect the life to be better (1) large capacity cells (2) have yet to discharge below 50% DOD (3) avoid amps above 300 so as not to warp plates. Hope to get 3 yr/10K miles at a minimum. Do the math, the pack cost $2200.
> Like the previous post, I wonder how long the small batteries will last under high amp loads. Like the tortoise & the hare, I may be slow and heavy… Let’s see who endures to the finish line.
> ...


Well I guess if your not going to draw more than 300 amps then that allows you to become cheap while picking out a controller doesn't it? Yeah I read about other people who don't like to let the battery drain below 50%. Makes me wonder how much that shortens the life, even if it cut the life in half to do that it still makes me think they would be better off buying half the batteries twice as often.

I can understand sitting on the fence trying to justify the cost if gas only cost 1.50 a gallon, but do you really still do that now?


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## the slashmaster (Feb 24, 2008)

Greenflight said:


> Yeah, 3-5 years seems about standard. You do have to keep up with the maintenance, though.


I was thinking about sealed batteries, anything wrong with that?


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## Greenflight (Sep 13, 2007)

Not that I know of... I have heard that they are less tolerant of ripple current than floodies, so if you want them to last, you may need a slightly better charger.


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## CPLTECH (Sep 14, 2007)

_the slashmaster__ "Well I guess if your not going to draw more than 300 amps then that allows you to become cheap while picking out a controller doesn't it? Yeah I read about other people who don't like to let the battery drain below 50%. Makes me wonder how much that shortens the life, even if it cut the life in half to do that it still makes me think they would be better off buying half the batteries twice as often.

I can understand sitting on the fence trying to justify the cost if gas only cost 1.50 a gallon, but do you really still do that now?"_

My controller is the Curtis 550A version, and yes there are many times that it hits close to that number… briefly. Glad it has that extra margin. As for the 50% DOD or less, I read that you can expect more cycles than doing the 80%. Will have to find out the truth in due time. Grid KWH in this area runs $0.107 – 0.12. At the current rate, the cost is an true/actual $0.07-.08 a mile. At $4 gal, that equates to 50-57MPG. Sounds good until batteries are factored in. Sounds fantastic as fuel goes up or rationed as in WW2 or limited in the early 70’s.


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## Coley (Jul 26, 2007)

Just how are each of us determining the DOD?

I use a hydrometer, but it seems that I am in the minority.

A load tester doesn't seem to be that accurate. It will show state of battery against battery but not determine DOD.


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## KiwiEV (Jul 26, 2007)

the slashmaster said:


> I can understand sitting on the fence trying to justify the cost if gas only cost 1.50 a gallon, but do you really still do that now?


It works out to over $5 US a gallon here now. I certainly require no justification!


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## MARTINSR (Mar 10, 2008)

Ok, this may be a stupid question as I am new getting back into the EV thing. Back 25 years ago, deep discarge marine type lead acid was all there was. So, here we are in 2008 and the first thing that has came to my mind as I start thinking about an EV again, is "jell cell" batteries like Ultimas. Do they work?

Brian


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## the slashmaster (Feb 24, 2008)

KiwiEV said:


> It works out to over $5 US a gallon here now. I certainly require no justification!


With all the trouble you went through to do that it makes me wonder but I sure hope so!


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## the slashmaster (Feb 24, 2008)

MARTINSR said:


> Ok, this may be a stupid question as I am new getting back into the EV thing. Back 25 years ago, deep discarge marine type lead acid was all there was. So, here we are in 2008 and the first thing that has came to my mind as I start thinking about an EV again, is "jell cell" batteries like Ultimas. Do they work?
> 
> Brian


Hi Brian, looks like according to this ev calculator http://www.evconvert.com/tools/evcalc/ there is 1 gel cell you can put in the equation to see how it works. Seems to me that for what it cost it better either be able to handle more amperage better or last longer than the other batteries in that chart for it to be worth it. But I'm no expert. By the way did you have a ev 25 years ago? I was just wondering how much things have changed since then?


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## MARTINSR (Mar 10, 2008)

No I didn't have one. I bought a bunch of books and had a passion for it, but kids, marrage, divorce,  you know the things that get in the way. I still have little kids at home and hot rods to build so I am still with many obstacles but who knows. 

I saw a very simple EV based on an older mini pickup where the motor is just bolted to the frame running off the rear axle and it got me kinda fired up on the EV thing again.

I live only 6 miles from work and I am thinking maybe I could do something with this....

I am not certain about the "one gell cell" you refer to. Forgive me I am seriously out of touch with all the technical stuff, never was good at that being I am a body man and I left the mechanical stuff to my brother.  But there are two Optima batterys on that site, I have no idea what the amp rating is on them by the part number. I will have to look into this a little.

Brian


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## JRP3 (Mar 7, 2008)

I think you'll want to look at AGM, (Absorbed Glass Mat), batteries rather than Gel. AGM's are Orbitals, Optimas, Odysseys, Universal, etc.


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