(ET) Specific Gravity

[Dick Both <dboth bmts com>]

In Reply to David Roden:

I think the mowing and my hilly estate does put too heavy a demand on my
three 12 volt batteries so I have taken to do half at a time (45 min).
then recharging for 2 to 3 hours and finishing. Batteries last about 3
years. The reason I have three 12 volts deep discharge marine is that's
the way I bought it and one was newer than the two others. I have no
other use for them and I hate to throw them away so I'm stuck.
There are automatic battery charger in local big box auto stores which
have regular and deep discharge settings for about $60 (12 amp). Would
these be good enough for finishing charge after a main charge from the
ET.  Another idea was a heavy duty rheostat inline inline to the ET
charger to cut back the current on the last 20% of the charging cycle. I
guess the best solution is get the schematics for microprocessor 36V
charger and jig it up to run full time.  Heard of such? Buying a 36v
external charger seems overkill as I already have the most expensive
component - the transformer.