But they don't risk thermal runaway... You probably know more about this than me, but I recall NiCads having a cut out point after which, for safety reasons, they would not accept a charge.
Dead Dewalt Battery Revivial
- Thread starter aveatry
- Start date
But they don't risk thermal runaway... You probably know more about this than me, but I recall NiCads having a cut out point after which, for safety reasons, they would not accept a charge.
The pressure is in the respective cells. The valve is at the top of each cell. You get a click and hiss if there is a pressure problem, I had read that if there is a pressure issue on cell (common with overworking them) it stops the battery working until it's released.
I thought what a load of cobblers, but I tried it and it worked for me. Mine didn't look swollen, so maybe the OP has different issue.
Ok thanks I have taken it apart and can not find any kind of valve, tried pushing down with a screwdriver but just ended up slipping and stabbing the work top
Those cells, are 18650's, a standard cell, and cheaply replaceable, if you are so minded. There is no valve that I am aware of, simply a design weakness in the case, to allow the case to burst under pressure - rather than explode.
Thanks
I like to try and fix things but there comes a point where it involves so much work that its not worthwhile to do
I was hoping for a magic hissing valve but could not find one - and now I have a stab mark in my work top
Thanks
I like to try and fix things but there comes a point where it involves so much work that its not worthwhile to do
I was hoping for a magic hissing valve but could not find one - and now I have a stab mark in my work top
Whilst you have it in bits, check the voltage, across each cell. They should show 3.7 to 4.3 -ish.
How will that work when they are all wired together - looks like a little spot weld
They are wired together, in series, to give to 20v. You can still check the voltage without disconnecting anything, putting your probes across the top and base of each cell in turn.
Ok they measure
2.88
1.35
2.85
0.33
Total at the contacts to drill 5.24
I have no idea what it all means though
Ok they measure
2.88
1.35
2.85
0.33
Total at the contacts to drill 5.24
I have no idea what it all means though
Your two at around 2.8v might be recoverable, but the other two, especially the 0.33 it seems they've had it.
Thanks.
Think I will keep it as it is and hopefully can use the good ones to repair another battery if my other old battery fails.
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