Suitable battery for powering spot welders

[Wouter KE]

For powering a spot welder lile the K-weld or the malectrics, I wonder which battery is less dangerous to power up the welder: LiPo or lead acid. LiPo batteries are known to ignite and even self ignite if not handled and stored properly; and burning LiPo fires are very difficult to extinguish. Even when stored there is still a risk of self ignition.
Storing Lead acid batteries is less a problem, but these batteries can release hydrogen gas, which is highly explosive. The way I see it, lead acid batteries close to a spark producing spot welder might also pose a potential risk. Anyone has given this some consideration or has (bad) experience with these setups? Or good tips or advice?

 

[rafalg]

I don't think you can ever have a problem with hydrogen released by a single lead acid battery - too little and only when charging.

 

[Diggs]

I use an AGM style lead-acid battery. I don't charge it (which is when H gas is formed) when I'm welding and it is sealed anyway. The last pack I made (14S5P) the AGM battery started at 12.87 volts and after 280 welds was at 13.03 volts with no charging. Go figure - heh! It goes back on a little battery keeper when welding is done.

 

[ganzey]

Go with lifepo4. Ive been using some old headways from batteryhookup for like 3 years now, they were $5/ea, 10 of them 2s5p. Works wonderfully, can deliver just shy of 2000A (running 6p gave overcurrent errors), and probably some of the safest battery cells made. Oh and they are cheap. I have gone over 1000 welds without charging, but you could charge them while in use with no worries.