dry charged batteris?

[miner49r]

Hiya Folks,
Still absorbing material before I pull out my checkbook and take the plunge. Although I plan on an "on grid" system, I am still researching batteries for a backup in the future.

It dawned on me that we batteries can be had in the "dry chardes" state. This led my to some investigating...

*WET-CHARGED: The lead-acid battery is filled with electrolyte and charged when it is built. During storage, a slow chemical reaction will cause self-discharge. Periodic charging is required. Most batteries sold today are wet charged.

*DRY-CHARGED: The battery is built, charged, washed and dried, sealed, and shipped without electrolyte. It can be stored for up to 18 months. When put into use, electrolyte and charging are required. Batteries of this type have a long shelf life.

OK... Since batteries degrade over time, would it not make sense to obtain dry charged batteries and put them in service when they are needed? It would take a day or so to get them filled up and charged but I see this as a way of minimizing investment loss over time.

Pros?
Cons?

I look forward to your comments.
Alan

[Sunking]

Alan Dry Charged batteries for the most part are only shipped to the dealers only. Then when the dealer sells them, they fill them, and charge them for 24 hours, then date stamp them to start the warranty period. Companies like utilities and telecom can buy them as they have been trained and certified to do the work.

Now there are some manufactures that will sell you Dry Charged Batteries and ship the electrolyte in a separate shipment. But generally speaking it is for very large capacity batteries to reduce handling weight and to meet state and OSHA regulations foe shipping hazardous materials. Once you cross the line of 50 pounds of electrolyte, the Employment Prevention Agency gets involved and all the materials from cradle to grave have to be documented, and permitted.

[PNjunction]

OK... Since batteries degrade over time, would it not make sense to obtain dry charged batteries and put them in service when they are needed? It would take a day or so to get them filled up and charged but I see this as a way of minimizing investment loss over time.

The active materials in the grids themselves have a limited lifetime whether there is electrolyte present or not. Note that we're talking common lead-acid and not specialty types. If just hoarding dry-cells was a real alternative, it wouldn't be a sudden revelation. I do admit I asked myself this very same question early on...

Let me jump ahead .. "what if I fill it up just before reaching the rated lifespan?"

The rated lifespan does NOT mean that it will be at rated capacity at the end of that time. You might be looking at 80% capacity or lower at the end of the lifespan when you fill and do the initial charge. You'd be paying for a battery with one foot in the grave, with less capacity than calculated and not support your load. If I were a dishonest battery retailer, I'd love to dump my new-old stock this way. Then when the capacity does not meet your needs, a second shelf-queen could go home with you to be paralleled to the first one.

Heck, even rechargeable new-old stock AA's are dumped like this. It's too bad, since the consumer then swears off rechargeable tech by being sold crap without knowing it.

[miner49r]

Thanks fellas for sharing your expertise.

Years back I remember helping our machanics fill new truck batteries. They never claimed that the shelf life was indefinite but did extend it. I guess we can't have our cake and eat it too.

Alan

[Sunking]

Thanks fellas for sharing your expertise.

Years back I remember helping our machanics fill new truck batteries. They never claimed that the shelf life was indefinite but did extend it. I guess we can't have our cake and eat it too.

Alan

Extend yes, but limited to about 12 to 18 months. That is the time a Dealer or Shop needs to cycle through inventory.

[thastinger]

I had a similar thread a couple of weeks ago.

Is it plausible to nitrogen purge and seal the caps on a dry charged battery to extend it's dry shelf life?

[Sunking]

Is it plausible to nitrogen purge and seal the caps on a dry charged battery to extend it's dry shelf life?

I would think so because that is what the manufactures do to get 12 to 18 months. The two most destructive and corrosive elements in our environment is oxygen and water both of which are in the air we breath.

[miner49r]

stinger,
I found your thread after I posted mine. (shame on me)
Nitrogen may just do the trick. I hate to put money into something that may not be functional when it is needed. I am leaning towards the SMA TL-US series grid tie inverter.

Actually, what did most folks do before electricity? They went to bed.

[Sunking]

Miner if you are doing Grid Tied forget battery backup. Get a whole house generator if you desire emergency power. Even with battery back up you still need the generator. Forget the batteries as they are just a useless expense.

[miner49r]

SK,
Your expert knowledge is always on spot. Batteries are an expensive consumable.

Thx, Alan