NiMh-NiCd Battery Chargers--Can They Be Converted To Charge Lithium Li-ION Batteries ?

202bigmike · October 21, 2014, 5:54pm

Only interested in the cells. My understanding at
the time , of his CL “he could make charger work
for lithium batteries ” statement , was that the NiHm
charger was not yet modified. Interpretation !

Bort · October 21, 2014, 9:20pm

No one wants to hear about your house burning down in a fire on the evening news, so please don’t accept hack jobs by someone trying to make a buck and sell garbage, lithium batteries are serious business and the few bucks you might save are not worth the resulting fire and explosion risk. In addition, lithium battery chargers are not expensive.

NiMH chargers work by trickle charging (low charge until you unplug it) or DeltaV charging where the charger detects the slight voltage drop when the battery is full and stops charging it. Lithium chargers are CC/CV chargers, it charges at a set current until the voltage is nearing 4.2 volts per cell then reduces the current in steps until the battery hits the full charge. If you use a NiMH charger on a lithium the voltage would be incorrect (for cells), or if you use a pack charger there would be no termination signal so it would overcharge until unplugged or the constant trickle charge even if it somehow terminated would also overcharge the batteries, both situations lead to a risk of battery explosion.

mmaghakian · October 21, 2014, 11:10pm

I think its an explosion waiting to happen

I bet he does this too:

•Never add lighter fluid directly to hot coals to get a sluggish fire going again. The flame could travel up the stream of fluid and burn you.

202bigmike · October 22, 2014, 2:23am

Bort:

No one wants to hear about your house burning down in a fire on the evening news, so please don’t accept hack jobs by someone trying to make a buck and sell garbage, lithium batteries are serious business and the few bucks you might save are not worth the resulting fire and explosion risk. In addition, lithium battery chargers are not expensive.

NiMH chargers work by trickle charging (low charge until you unplug it) or DeltaV charging where the charger detects the slight voltage drop when the battery is full and stops charging it. Lithium chargers are CC/CV chargers, it charges at a set current until the voltage is nearing 4.2 volts per cell then reduces the current in steps until the battery hits the full charge. If you use a NiMH charger on a lithium the voltage would be incorrect (for cells), or if you use a pack charger there would be no termination signal so it would overcharge until unplugged or the constant trickle charge even if it somehow terminated would also overcharge the batteries, both situations lead to a risk of battery explosion.

Thanks for your concern. I was not going to buy his
batteries or his charger. The $$ was just too much for
either. I understand that these Lithium batteries are
not to be taken lightly. They can almost be described
as IED’s—Improvised Explosive Devices, if not treated
with the proper care and attention to safety. Once again,
thanks for the concern.

Bort · October 22, 2014, 2:31am

202bigmike:

Bort:

No one wants to hear about your house burning down in a fire on the evening news, so please don’t accept hack jobs by someone trying to make a buck and sell garbage, lithium batteries are serious business and the few bucks you might save are not worth the resulting fire and explosion risk. In addition, lithium battery chargers are not expensive.

NiMH chargers work by trickle charging (low charge until you unplug it) or DeltaV charging where the charger detects the slight voltage drop when the battery is full and stops charging it. Lithium chargers are CC/CV chargers, it charges at a set current until the voltage is nearing 4.2 volts per cell then reduces the current in steps until the battery hits the full charge. If you use a NiMH charger on a lithium the voltage would be incorrect (for cells), or if you use a pack charger there would be no termination signal so it would overcharge until unplugged or the constant trickle charge even if it somehow terminated would also overcharge the batteries, both situations lead to a risk of battery explosion.

Thanks for your concern. I was not going to buy his
batteries or his charger.

cool 8)

202bigmike · October 22, 2014, 2:47am

About the explosion waiting to happen, you could be
correct.—Read my reply to Bort above. Now about the
guy with lighter fluid on hot coals.-I don’t know him !
He might not have a grill at all or maybe he has a
propane grill. Just a little too much supposition