Next message: David, Anne Marie and Hannah: "Re: lv-ab: Live aboard decisions"
I haven't followed you discussion closely, so perhaps I'm missing
something. But:
You show 1 volt difference between banks - a huge difference. If one
charger supplies both banks, then there is something very different
about the way the "back" bank is connected. *If* the banks are supposed
to be ganged in parallel, you have a bad connection. It *may* be the
wire size is too small or one (or more) of your terminals is bad.
Also, as I understand it, you must calibrate the hydrometer, in the
sense that no two batteries are exactly alike in their readings at
"full", "half", and "empty". The battery needs to be fully charged
(based on current it accepts at a certain applied voltage), let rest for
24 hours, than tested with the hydrometer and the readings recorded for
that battery; then drain it 25% of rated amp-hours using some known
load, let it rest 24 hours, and test again with the hydrometer and
record the 1/2 empty readings. Repeat to get the empty readings. Now
you have calibrated you hydrometer as a gas gauge - for that particular
battery. If you do not have completely new batteries, then you should
first determine their present capacity by fully charging, then draining
them down to the "empty" voltage - there are a couple tricks to this,
and if I recall, the process is described in "This Old Boat".
Kinda nitty picky, and perhaps not significant enough to worry about -
guess it depends on how anal-retentive you want to get about your
batteries.
Rufus
kaha wrote:
> "Float" the reading on the back batteries was different then on the
> front.
>
> Front battery set: Specific gravity = 1.273
> Voltage = 14.33
> Charge % = 100%
>
> Back battery set: Specific gravity = 1.225
> Voltage = 13.34
> Charge % = 72%
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