On 11/16/2013 10:40 PM, Mike Marlow wrote:
woodchucker wrote:

What Leon was referring to is balancing technology. Which makes sure
each cell is in range, and not deviating from the others.
That is actually where most of the problems are, especially with low
end chargers. The better chargers will monitor each cell rather than
the pack and if one cell gets higher than the other it will deplete
it while bringing the others up. If they are too far out it shuts
down.

How do you monitor an idividual cell when they are connected in series?

Generally they are not just connected in series.
Nicads and nimh were, but not lion or lipo.


The better batteries have prongs for the drill, or whatever
and another set for monitoring the cells. Charging can be done on the
normal prongs, but monitoring is done on the second set. They are not
monitoring for heat like nicad and nimh, they are monitoring for
voltage. They need to be close, and they can't exceed the recommended
cells voltage. Same with depletion of batteries, they can't be drawn
down to low or they may not charge again, or worse. So the manufacturers
have handled that. You'll see all the lion/lipo units stop when voltage
drops. So if you are drawing a lot of amps it will cut out. let it cool
and the battery bounces back a bit and you can continue... but it's a
matter of time b4 it stops running and needs charging.

Even the cheapies have something, probably not as good. Take a look at
your pack, you will see another set of connectors.

I love the Lithium technology the drills are always ready. No quick
discharge like the nicad/nimhs had.




--
Jeff