# Which 'deep cycle' battery has longest life?



## Sub_Umbra (Jan 12, 2006)

Every 6 months or so someone starts a thread about using a solar panel to run a battery charger. Eventually someone mentions putting a deep cycle battery between the panel and the charger. I'd like to know which deep cycle batteries have run the longest for you before dying. Actually, I'd like to hear how many years you got from different brands of batteries you use in *any* deep cycle application -- golf cart, summer cabin, boat, RV, whatever.

I'm thinking that the 'serviceable' batteries have a better chance than sealed cells, but I don't know.

Which deep cycle batteries have served you the longest? The shortest?

Thanks


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## JimH (Jan 12, 2006)

Concord AGM and Hawker Odyssey (also AGM). Check 'em out.


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## turbodog (Jan 12, 2006)

Look into some used ups batteries.

I've got 12 car battery sized ups batteries, 90ah each. I have no idead what to do with them. They are 60% of new capacity, and will likely be throw away.

They go for about $150 each new, retail.

If someone wanted them, I would sell them for about $5-10 each. But I will not ship them.


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## BatteryCharger (Jan 12, 2006)

Hawker, by far.


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## wasBlinded (Jan 12, 2006)

With regular maintenance, including periodic equalization of the cells, flooded lead-acid batteries like those from Rolls will last longer (more cycles) than AGM or gel cell batteries. AGM batteries have their advantages, including lower self-discharge rate, greater vibration resistance, and higher charge rate acceptance, but (high quality) flooded cells will still last longer, and are usually cheaper per amp-hour to purchase.


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## Sub_Umbra (Jan 12, 2006)

Thanks guys.

I'll be setting up this rig to charge AAA-AA-C-D cells with my Accupower 2020 if I can iron out the hardware choices and panel mounting. I've wanted to do this for a while and now, in the post Katrina world, Mrs Umbra has suggested that I go ahead with it before the next hurricane season.

I plan to use it throughout the year for all of my charging *in addition* to having it available for emergencies. Because of our need to rely on it for emergency use I won't be using any used or surplus batteries.

I'd like to strike a balance between price and service life in my choice. 

Anyone have any idea how many years I can expect to get from any particular battery model that gets good maintainance? How long I may expect it to last will impact how much I can spend for purchase.


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## BentHeadTX (Jan 12, 2006)

Sub,
I was doing research on lead-acid batteries several months ago when I needed to build a new 36V battery pack for my electric scooter. It demands 35 amps at 36 volts and must handle strong vibration, cold weather and be legal to fly on aircraft. My choice was SVR 14AH AGM cells as they can punch out 900 amps for 10 seconds (1,500 amps peak) which is pretty zesty for a 11.5 pound battery. They are rated for Electric Vehicle drag racing and laugh at my 1000 watt brushless motor (scooter heavily modified) The two brands that work well for EV racing are Hawker and SVR. 

The longest lasting lead-acid cells are things called "traction" batteries. They are rated for 10 to 20 years but as wasBlinded says... they require maintenance every 6 months to add water. Once every five years the acid is drained, the cells washed to remove lead, filled with water and a charging current applied to clean the cells. Reload with new acid and run them another 5 years etc. These cells are generally used in giant UPS systems and as storage for wind mills, solar arrays and the like. They are large, very heavy and expen$ive but you can't beat the durability, capacity and longevity. 

I would get some wet cell, UPS batteries and a great trickle charger or curcuitry to monitor the solar cells. A great web forum to learn about batteries (besides CPF) is called "V is for voltage" forum were lead acid and AGM cells are discussed in depth.


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## VidPro (Jan 13, 2006)

on the alternative energy forum, they are getting about 8 years on the Massive 400A trojan wet cell things.
i think the plates are huge on them. and the LEVEL of deep discharge is important.
if your going to use Lead Acid, i would recomend having TO MUCH, so you can cycle it low many times, but not cycle it deep ever. there is of course a balance, bceause they have self dicharge too, and you dont want to waste your solar day just re-topping them off.

i would Never use a gell cell for solar, because . . . cause i hate gell cells  they dont take many deep discharges, and overcharge is very bad for them. they work GREAT for UPSes that will stay perfectally charged and be discharged rarely. but for solar in the winter they are either going to be suplimentally charged or ruined, when they just park with a low charge.

Golf cart batteries, and big trojans, are for them large storage operations. if it was for a Smaller thing, i would really want to look into the Rolled cell styles, like the hawker, or them "race car" batteries similar. the old 2V hawker rolled lead acid F cells worked good for me for a long time.

the choice of lead acid is because it cheap, and that seems to still be the choice.
but if you ask me them FAT li-ions with 80AMPs and a proper curcuit stuff would be ultimate. the fat ones will take many full discharges, they CLAIM "millions" of short discharges.
if only i could get 50,000$ for batteries together 

i have been testing a 100A 3.6v small li-ion solar pack, and winter came, and pooo, no more solar during the continual heavly clouds.
low voltage is really stupid (ok i learn the hard way) because of distribution with the wires, has so much loss.


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## snakebite (Jan 13, 2006)

turbodog said:


> Look into some used ups batteries.
> 
> I've got 12 car battery sized ups batteries, 90ah each. I have no idead what to do with them. They are 60% of new capacity, and will likely be throw away.
> 
> ...


too bad you are not close by.
i recycle lots of those by testing and handing them out to local hams for emergency power.
often its one bad one in the series string.
i usually find 1 dud and the rest check out 80%+ on a rc test.


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## Sub_Umbra (Jan 13, 2006)

Thanks all. This has been a big help.


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## cobb (Jan 21, 2006)

Most wheelchair dealers and some manufactures use MK series series sealed gel cells. The cheap included batteries they use are either delco or some other brand for lead acid wet flooded cell brands. 

I had a set of delcos, they lasted 3 months with daily use. Had a set of walmart wet cells. Much more umph, charged fast, still lasted only 6 months. MK, I am on 7 years. Not much umph, takes FOREVER to charge, but still kicking. Sure 7 years is 11 times better than 6 months, but they always feel like they are dying, but keep on going. They take agood 8 hours to recharge with same automatic charger. I rather have cells with some kick and charges fast.

Ive had folks say AGM is great, the spiral brand of batteries uses them, but their amp hour rating is lower than standard wet or even gel cells. 

If I had to buy new batteries, I would want something youcan clean. Unless of course those desulfur things really work.


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## Sub_Umbra (Jan 21, 2006)

Thanks.


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