On 5/15/2024 3:26 PM, Mark Jones via KRnet wrote:
Some batteries are now coming with a built in BMS. Battery maintenance
system. Mine has one and I have already seen it work. It will not
allow the battery to discharge past a certain point. There is an
internal cut off switch. I was draining my battery by cranking the
engine with fuel valve off ( by mistake) and all of a sudden I had no
battery power. Ten seconds later it came back up but needed charging.
Slapped a lipo smart charger on there and it’s good as new.
Mark Jones
Oldsmar, Fl
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All "rechargeable" lithium batteries have a circuit board that monitors
charging, discharging,and temperature too hot /cold. Even the small
rechargeable cells similar to an "A" size battery will have a mini ckt
brd the size of your pinky fingernail, usually concealed under wrap on
the + end. Your lithium powered drill can drive a 3" screw in to solid
oak and the next time you pull the trigger it's dead. The CKT BRD will
not allow it to discharge below a specific voltage level (30% ?) or the
charger will not turn on to recharge the pack. Any multi-cell pack will
be monitored for balanced cell charging. Pack too hot or too cold and
you get a "bad pack" flashing light. The technology of these battery
packs, yes your 12 volt battery is still a pack, multi-cells, that is in
no way similar to the black plastic containers with lead plates and acid
and you must insure they are compatible with the system in which they
are installed. Each type of battery has it's own unique characteristics
/ requirements / failure modes. Know what they are and proceed accordingly.
Here is a photo of a simple little 3 -18650 cell pack and the ckt board
(BMS) . Your 18 volt drill pack will have 6 of these cells.
Larry Flesner
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