SLA batteries

[MRF]

Anyone really familiar with sla batts? I'm not sure what they mean by sealed if they release gas while charging. What I want to know is if the leads are isolated and sealed is the battery submersible? What kind of preassures might is withstand if it is?

Thanks. :shades:

[TomP]

Steve Lindblom's - Dive Light Companion is a good source of info on batteries. SLA are considered sealed because the electrolyte is absorbed in glass fiber mats between the cells. The gas created during charging exits through a one way vent.

If you remember old style car batteries which had vented and removal caps and elctrolytes sloshing around in the cells, the differece becomes pretty apparent.

I also remember seeing at least one DIY project where a naked SLA was submerged but i'm not sure it's a great idea.

[cool_hardware52]

Anyone really familiar with sla batts? I'm not sure what they mean by sealed if they release gas while charging. What I want to know is if the leads are isolated and sealed is the battery submersible? What kind of preassures might is withstand if it is?

Thanks. :shades:

Sealed Lead Acid batteries are sealed in that you can't add electrolyte. The cells have pressure vents, IIRC set at around 60 psi. You need to overcharge them at a fair rate to get the vents to open.

Even so the possibility of Hydrogen generation is present, and all Lead Acid batteries need to be charged in an open environment (not closed up in a canister or scooter) to prevent the possibile build up of an explosive mixture.

I would not plan on using just a bare battery exposed to the water. In fresh water you might get away with it, in salt water no way. Not sure what you mean by isolated leads. Isolated from what?


Tobin

[MRF]

Not sure what you mean by isolated leads. Isolated from what?
Tobin

Yeah, I guess I wasn't too clear there. Basically, isolated from each other. My thought was to seal the conductors so that they could not short out.

Here is my situation- I started a light project. I bought some 10ah sla cells only to discover that the tube I need to seal them in is prohibitive in size ("Missed it by THAT much") - (unless I want to band it with an 80cf tank and wear it as doubles). So I was wondering about the feasability of leaving the batteries exposed to the H2O while sealing the conductors. I just don't want to set up a situation where my batteries will do damage to my plate or wing.

Thanks for the help.

Murph :shades:

[IslandFrog]

My family owns a battery store, and taking a bare SLA battery underwater is not something that we would recommend. I know that we have replaced the SLA's on a DPV unit for a LDS, but they were enclosed in the case.

If anyone is interested, there are a couple of books available on Amazon that we have found helpful to have around. They are:

Batteries in a Portable World by Isidor Buchmann and
Understanding Batteries by R.M. Dell.

Hope this helps.

Regards,
Brad

[kidspot]

Here is my situation- I started a light project. I bought some 10ah sla cells only to discover that the tube I need to seal them in is prohibitive in size ("Missed it by THAT much") -

was your original cannister going to be PVC? If so you can soften the PVC in the oven, shape it around the battery, and it will have a nice form fitted appearance to it.

[MRF]

was your original cannister going to be PVC? If so you can soften the PVC in the oven, shape it around the battery, and it will have a nice form fitted appearance to it.

OUTSTANDING!! Perfect solution. Thank you!

Any suggestions on making the removable lid once it is out of round?

Thanks.

[kidspot]

nope ... lol - sorry...

You might also pick up a copy of Airspeed Press' book "Divelight companion" for ideas... http://www.airspeedpress.com

Actually one idea would be to permanently seal an end cap on, then drill out a round hole - you won't be able to remove the battery, but you could open it up to vent during charging...


Aloha, Tim

[Firediver]

For your removable lid just use a clean out cap.. and change the plastic oring with a rubber one... the one on my scooter works fine.. the scooter however is another story......