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[email protected] fairbank56@yahoo.com is offline
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First recorded activity by BoatBanter: Jul 2006
Posts: 18
Default diode in charging circuit

On Nov 15, 6:56 am, wrote:
Confused? I'm not the one who thinks a $140 work-ariound is superior to a $50
Solution. :')


Neither am I. He asked if he could use a diode to drop the voltage
and if so, what kind.


And here's a little tip: An AGM battery can be effectively charged at 13.5
volts.


And your point?

A flooded battery needs more than that just to begin charging.


FALSE!

difference in internal resistance. And for purposes of this thread, the
essentially unregulated voltage from a 10 hp Honda outboard IS enough to quickly
ruin an AGM battery.


Quickly? I doubt it. I doubt the thing can output more than 10 amps if
even that much. Once the AGM is fully charged, it can still stand the
15v for several hours with no ill effects. I have a Lifeline AGM
GPL-24T right here in the shop that's fully charged but been sitting
for a while (no surface charge). I just put a constant 15v on it and
it started charging at 4 amps. After 5 minutes it's down to 2 amps and
in the next few minutes it will be down to a couple hundred milliamps.
I can leave it on this way for hours and it ain't gonna hurt the
battery. I can fully test this battery with my carbon pile load tester
to prove that the battery hasn't been quickly ruined.

Eric