Boat Forum / Electronics / December 2006

fritz@thegreatsea.com wrote in news:1166839615.657599.210950
@f1g2000cwa.googlegroups.com:

Just get a charger with no shutdown electronics and keep charging it at
capacity/20 for another 8 hours.  Keep a CLOSE eye on them for percolating
acid all over or overheating.  This charge MUST be done SLOWLY....not some
cowboy 50 amps to warp the plates.

SLOWLY is a keyword.

Here's some good information:

http://www.shaka.com/~kalepa/technotes.htm

"First recharge the cell and then continue to charge the cell at a C/20
rate for five to seven hours. During equalization charges, the cell voltage
will become very high, about 2.7 VDC per cell. This overcharge contains the
necessary power to break the Level Two bonds and force them to Level One.
Once they reach Level One, the bond is easily broken and the sulfate ions
reenter into solution in the electrolyte."

So, if we have a 130AH deep cycle, we'll be charging it for an extra 5-7
hours at 6.5A....OR LESS!  Any ol' cheap charger without SCRs and computers
will do it.

DO NOT LEAVE THESE BATTERIES UNATTENDED DURING THIS PROCESS!  DO NOT
OVERCHARGE THEM AT HIGH CURRENT!

Read his comments about this "pulse charging" nonsense, too....