[C320-list] Flooded acid battery and refrigeration questions

[Troy Dunn]

Wow, so many things going on here at once.   This thread may grow beyond
one of those "which anchor is better" debates.

One thing we need to clear up.   Boiling off generally will occur when a
battery is closing in on a high state of charge (so generally low amps)
with a higher voltage applied.   So for instance on my batteries I can
supposedly bulk charge (aka constant current at a target voltage of 14.9
and drop back to about 14.6 for absorption (constant voltage) and then back
to something closer to 13.5 for floating on the alternator.  I have learned
over time that because I’m not a full time cruiser, I don’t really
want/need these aggressive charge profiles and I back this off a couple of
tenths to slow down the boil off (this seems to have helped, perhaps at the
expense of maybe some top end battery life expectancy…but GC2s are so
affordable it’s really a don’t care.)

What caught my attention was the possibility of the MPPT resetting it's
charge profile each day (I assume triggered by sunlight hitting the panels
and creating current once again?).  This seems like a horrible thing if
true, and would absolutely be a problem.    You can bet you are cooking
your batteries if you have a decent sized set of panels that get you to
float in the first day or so.   If you find this to be true, find out if
there is some other setting you can use to prevent that from happening.

Lithium Ion on a boat?  Not a good idea.  If you meant LiFePO4…sure, if
cost is not a factor, go for it..you can fit way more capacity in the same
space, the batteries will last longer than either twofootitis or swallowing
the anchor in most cases, you won’t kill your back installing them, etc.
Just admit you like spending money to have the coolest batteries and also
be prepared to upgrade all of your charging systems if they are not forward
compatible with LiFePO4 chemistry.  Battleborn and DIY builds from single
cells and a BMS seem to be the preferred choices of many live aboard full
time cruisers.

There is one battery monitor that is closing in on delivering on the
promise of being pretty smart and pretty hands off.   That’s the Balmar
SG-200.   I was a somewhat early adopter of this gadget and was very
disappointed with the way Balmar handled the roll out of this device.   The
first few software versions were very buggy and did not deliver on the
marketing hype.   They also required you to purchase a Bluetooth dongle in
order to get the firmware upgrades onto the device.   This really soured
the community and if you go out to cruisers forum you will find a
ridiculously long thread there that will definitely be a turn off.   I can
say that Balmar has finally worked out a lot of the bugs and I believe now
that the device is delivering on the promise.   Also…despite the grumbling
of the community about having to purchase that dongle…it does enable the
phone app which is really a game changer and so, it really is worth it.

FWIW

Troy