Need help charging battery pack for welding respirator

Im a welder and hate the fumes i breathe in- I found a speedglas welding hood with a fresh air respirator at a pawn shop. The respirator has a battery pack but didnt come with a charger- nowhere on the battery pack does it say how many volts its running or what amount of volts to charge it- I need to charge the battery pack to see if the respirator works- I have a radioshack ac universal adaptor that came with all the different plugs and can be set from 1.5 volts to 12v- what setting should i charge the battery pack with?

Ive googled the part number and found nothing- even went to speedglas's website and searched the product number and its like it doesnt exist- the respirator is there last model- not the newer one- but one would think you could at least find some info. The battery pack says NICd- I have it hooked up right now to my ac universal adaptor charging at 4v. The wierd thing is that the battery pack doesnt say how many volts it operates at or how many volts to charge at. I assume the fan inside the respirator should run off 12v - Like most small PC type fans. And I know my cordless 12v drill battery packs recharge with 24v but im scared of ruining the battery pack or making it blow up since I can still get a refund by monday. Speedglas's new respirators cost $1000- I paid $190 for a speedglas welding hood and there old style respirator- you can't buy the air filters for the old ones anymore but found a guy on ebay selling new ones for cheap. I tested the fan in the respirator at 6v and worked fine. The lens in the welding hood does not work but if i can get this respirtor working i think its well worth what i paid since i have a new speedglas hood it will work with. If the batterypack is dead couldnt i replace the cells inside with rechargeable batteries soldered in a series??? thanks for all who help me out

#of cells*1.2V should do it. Really you should be using an RC smart pack charger with a cutoff.

I dont know the number of cells- Whats different about an rc smartcharger besides that it cutsoff charging after a certain time- How would i know which one (output) to buy? And can you buy them at radioshack?

You can not guess about the contents of a battery pack by examining it externally. The cells may be 1/2 length, they may be wired in parallel or serial or a combination.

I'd look for someone who can open it and figure out what it's voltage and capacity are. You can then find a battery pack from elsewhere ( rc model, tool, etc) that will fit the need.

Daniel

Get a cheap multimeter (they should have them at RS or other stores like Fry's, Sears, etc.) so you can find out the voltage of the pack. Then, get a pack charger for the appropriate number of cells here.

Pack is probably flat if it's from a pawn shop.

A multimeter will not help if it's an old nicad pack. One or more cells are likely to be either open, shorted or just 0 volts. This will lead to erroneous readings.

The voltmeter only helps if you have a healthy pack to check.

Daniel

There's likely no way around taking the pack out and seeing what is in it.

I have yet to find a battery pack that I cannot take apart, replace bad cells, or make a new one with better cells....with one exception: my induction charged electric Philips toothbrush that has the NiCad encased in a core of epoxy filled into the plastic handle to keep it all sealed.