[C320-list] Battery Woes

[Troy Dunn]

Dean

Yes, your bilge pump is always on and therefore is wired directly to one of
your batteries at the back of the selector.  This ensures that your bilge
pump when correctly set to auto will still operate when your 1/2/BOTH/OFF
switch is set to OFF.   A fully charged battery does us no good if our boat
sinks.

200mA would take almost 2 weeks to draw your fully charged 4D battery to
50% SOC...maybe longer.   So, you have something else going on.   200mA is
still a high draw however...you need to investigate that parasitic load.
It may lead to finding something more insidious.

I'm starting to wonder if your charger is shot.    In fact this is the most
logical conclusion so far, but unfortunately much more data/investigation
is required.

Having two new batteries simultaneously go belly up is not unheard of...but
it is a low probability event.   Did you check the manufacturer date on
those batteries?  If the dates are more than a year old then yes you got
bad batteries because they self discharged and sulfated beyond the point of
recovery.  Sometimes there is a sticker.  There is also usually a date code
stamped into the lead post.   The manufacturer usually can tell you how to
get that code and turn it into a date.

13.4 V is an incredibly low bulk/absorption charging voltage.   At that
voltage it will take a long time to fully charge your battery.   A day at
least I'm thinking.    That number had me scratching my head a lot.

Are your battery cables installed correctly?   There should be no washers
between the cable lug and the lead battery post.  Stainless steel is a very
poor conductor compared to copper, lead, aluminum.   Incorrectly installed
washers can cause serious voltage drop, poor charging, high heat, and in a
worst case scenario...melt your battery casing.

Check connections at the back of the selector switch,  the battery negative
connection at the back of the breaker panel, the battery ground at the
starter motor/engine, and all connections at the charger...check those
charger connections for signs of overheating too.

If these things don't turn anything up...it might be worthwhile to pull a
battery and take it back to get a proper load test.   I know that’s a pain,
but at least you will know if the SOH of the battery is good/bad.

What type of charger do you have?  Some are more prone to early failure
than others....



Troy Dunn
Hull#514
Wonky Dog