I have luckily never steamed/cooked a golf cart battery, but in the two
packs of golf cart batteries I have had, there was always one battery
that failed "first".
I have a (now no longer available for purchase) PakTrakr system that
reports on the voltage level of each battery, and this was very helpful
in knowing when a battery was not performing "up to snuff" w.r.t. the
rest of the pack.
This would typically exhibit as one battery being at a significantly
lower voltage than the others, especially when under load. (for example,
one battery would sag to 4.9 volts, while all the others were at 5.5
volts). This battery would have lower capacity than the rest of the pack.
The overall pack voltage would look just slightly lower than normal, but
I imagine that if I were to keep driving the pack the lowest battery
would eventually reverse, get sizzled, etc...
If only for this, I think having a per-battery voltage level monitor can
be useful. A Lee Hart style middle of pack imbalance monitoring system
could also give an indication that something like this was going on, but
wouldn't necessarily identify the specific battery.
The "bad" battery would also typically be 0.1 volt lower than the "good"
ones after charging, but that difference was not as big an effect as the
voltage sag under load (which is difficult to measure with a multimeter
while driving ;>)
On the first pack, I purchased a (brand new) golf cart battery and used
it to keep the rest of the pack going for another six months. On my
second pack, I had two spares from the first pack that I was using in a
large UPS, and I swapped one of those in to keep things going for a
little longer.
Jay
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