Paul Dove via EV wrote:
If you have... no BMS and you are monitoring the cells, that
should be all the data you need to decide if a BMS is necessary.
That's a good point. With new, well-matched cells, you might be just
fine (at least for now). Since crappy BMS can create as many problems as
they solve, you may be better off just monitoring them yourself (you
become the BMS).
My simply little Batt-Bridge is one way to tell if something is going
wrong without obsessively monitoring the cells all the time. It doesn't
tell you which one is different, but it alerts you that it's time to get
out the voltmeter and find out!
There are also some mighty simple voltmeter circuits that can be used
with a small number of cells. Traditional analog meters can be found
that draw very low current (well under 1ma) so they can be left
connected all the time.
Or, you can use super-bright blue or white LEDs as voltmeters. They need
at least 3v to light, and can be quite visible with less than 1ma.
Choose a series resistor for (say) 1ma at 4v. Then the brightness will
vary from 0 to max as the cell goes from 3v to 4v. Mount them all right
next to each other in a panel. The human eye is extremely sensitive to
brightness, so you can easily judge which one is the brightness (highest
voltage) or dimmest (lowest voltage).
--
If we knew what we were doing, it wouldn't be called research, would it?
-- Albert Einstein
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com
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