View Single Post
  #8   Report Post  
posted to rec.boats.cruising
Larry Larry is offline
external usenet poster
 
First recorded activity by BoatBanter: Jul 2006
Posts: 5,275
Default Charger - House Bank Sizing

wrote in news:1191374548.703118.153360
@r29g2000hsg.googlegroups.com:

Thanks for the info. I forgot to mention,, yes I have four wet

cell 6v
T-105s.



Another consideration, Chris, is COOLING the charging batteries
noone likes to consider. Yachites like things really neat, so
put the batteries in this sealed up wooden box that acts just
like a hot box for the poor batteries charging.

Heat is generated the old fashioned way during the chemical
change:

Power = Volts X Amps.

If you're charging at 14V at 40A that equals over a half a
kilowatt of electric power that is converted into heat by the
charging process. You can imagine how hot this could get in a
hot engine room where some idiot put the batteries to hide them
which starts out at 130F. The batteries are already hot when you
start charging them.

If you keep shoving AMPS, AMPS, AMPS into them, not matter what,
trying to "Yachtie Charge" them in minutes, and leave them
charging like this as the temperature rises, you can warp the
plates, boil the electrolyte, etc., etc. It's not rocket science
to see this isn't good for the batteries in the neatly-painted
wooden box that has 3 holes drilled in the top of it for the
wires to come out. Proper battery installations are always
VENTED, to let BOTH heat and hydrogen gas escape. Your car has
its battery located so plenty of cooling air gets to it, for
instance.

Please consider this when buying more AMPS to shove into them.

Larry
--
Please - Turn OFF cruise control when
you turn on windshield wipers!