Long term battery storage

[RicRac]

I would like to store several batteries to use with a small solar array. This will require them to be purchased and stored dry. I am finding it impossible in California to find anyone that will sell battery acid separate. Any thoughts how to get around this.

[Buggyout]

Visit Nevada.

(fellow Californian)

-Buggy

[CountryGuy]

Move out of CA?

[RICHFL]

We get them here in Florida from Wal Mart......

[CountryGuy]

OK, if you're not going to move, can you mail order or will companies not ship them to you dry with acid seperate? Can you check a chemical supply house near you where you might be able to buy? I think it's typically sulfuric acid isn't it? I don't know if the acid the battery company ships has any other additives.

Maybe going to an AGM type gel battery instead?

[Murphy]

I've been researching this for the past two months.

Batteries that are sold for sports equipment like motorcycles and jet ski's are sold "dry charged", but they are so small they are useless for anything more than running a few small LED lights or a small radio.

There is only one manufacturer that I know of that sells a deep cycle battery in a dry charged state and that is ROLLS.. and the cheapest one is a 6 volt battery at around $900.. Since I have a 48 volt system, that's 8 batteries times $900 for me.. OUCH! And that doesn't even include shipping.

I talked to the tech guy's at Trojan and they do not sell dry charged batteries.. They ship them without acid, but they are not dry charged as acid was once in the battery. The guy said its better to call it "moist charged".. and they won't store well.

I had even come up with a procedure to try to store them and they said it wouldn't work on anything NOT dry charged.. Apparently, dry charged means "never seen acid".. just because a battery has had the acid drained for shipping, its not dry charged and only a dry charged battery will store for long time frames.

I also talked to the guys at Rolls and they said even their dry charged batteries will only last for less than a decade on the shelf.. So then I asked them about storing them in an oxygen depleted environment and they said if I could do that, it would work good..

So, if I buy the Rolls, I'll be putting the batteries in Mylar bags with both oxygen absorbers and desiccates and they should last nearly indefinitely. But damn is that expensive.. $10K for me to get 24kW of energy storage.

[Nik]

Can you provide a trickle charge to keep wet lead-acids happy ? Doesn't take much, but keeps them healthy. A small, yachty or vertical axis wind generator and/or a modest solar panel should suffice. Don't forget the simple isolating diodes...

Also, IIRC, there's a world of difference between 'car/truck' lead-acids, designed to crank a starter with 100 Amps or more, and 'recreational' lead-acids, which don't tolerate such usage or deep-discharge but otherwise last a lot longer.

[Murphy]

Can you provide a trickle charge to keep wet lead-acids happy ? Doesn't take much, but keeps them healthy. A small, yachty or vertical axis wind generator and/or a modest solar panel should suffice. Don't forget the simple isolating diodes...

Also, IIRC, there's a world of difference between 'car/truck' lead-acids, designed to crank a starter with 100 Amps or more, and 'recreational' lead-acids, which don't tolerate such usage or deep-discharge but otherwise last a lot longer.

Once a battery has been exposed to the electrolyte (acid+water), its on a self destruct timer.
Yes, if you keep the battery fully charged and exercise it once in a while, you can extend its shelf life.. but its only an extension, it doesn't preserve the battery.

[grumpygremlin]

off grid electricity isn't really my thing, post SHTF i'm going "old school" and keeping it simple.
we live in a modern house(23-25 years old) and we just haven't got the storage for this sort of thing.

[Defcon09]

I would like to store several batteries to use with a small solar array. This will require them to be purchased and stored dry. I am finding it impossible in California to find anyone that will sell battery acid separate. Any thoughts how to get around this.

Did you try auto parts store that sell batteries? Like NAPA or AutoZone?

[Murphy]

Did you try auto parts store that sell batteries? Like NAPA or AutoZone?

It's not an issue with the retail distribution, the problem is at the manufacturing level. The manufactures fill the batteries with electrolyte and charge them up for testing and quality control. They frequently then drain the batteries for shipping purposes (sulfuric acid is dangerous)..

Once the batteries have been filled at the factory, its too late.. there is no preserving them after that.

In order to store a Lead Acid battery for a long time, it must be manufactured and shipped DRY CHARGED... having never seen a drop of acid.. You then stick it in a mylar bag with an oxygen absorber and seal it up. (just like you would with food).

The oxygen absorber will scrub the oxygen and prevent the lead plates from forming lead-oxide. The process would be slow even if you didn't put the batteries in mylar.. the battery would still be good after 5 to 10 years, but adding mylar and 02a would extend it nearly indefinitely for decades upon decades.

[Nik]

I've since seen some advice on storing wet-charged lead-acids.

Drain acid, rinse several times with distilled water, flush dry with nitrogen, seal.

I suppose welding argon would do at a pinch.

Note this is NOT a substitute for 'dry charged' cells, but should provide a set of lead-acids for when your primary set age. Also, recommended 'leisure' rather than 'starter' batteries due to manufacturing differences.

[Defcon09]

Aren't the "no maintenance" or sealed batteries, shipped with the acid inside already? How else would one put acid in said battery?

[Murphy]

I've since seen some advice on storing wet-charged lead-acids.

Drain acid, rinse several times with distilled water, flush dry with nitrogen, seal.

I suppose welding argon would do at a pinch.

Note this is NOT a substitute for 'dry charged' cells, but should provide a set of lead-acids for when your primary set age. Also, recommended 'leisure' rather than 'starter' batteries due to manufacturing differences.

Its poor advice and won't work as well as they claim. You'd almost be better off just filling it up and keep it charged in a cool area.

I covered all this with the Trojan engineers.

Lead acid batteries are a workhorse, but they have their drawbacks like everything else.

Really, the best solution is to go with a Lithium Ion battery.. and now they have Lithium Titanate batteries making it to market! LTO (Lithium Titanate Oxide) could very well be the last battery you ever have to buy. They have a cycle life rated into the 20,000+ level and can be fully charged, fully discharged, and fast charged.... and they don't go boom, even when punctured or cut.

Sit down when you see the price.