Charging a Battery Bank
I am planning on upgrading my batteries to 4 6v batteries wired in series and parallel to have a 12v system with plenty of Amp Hours. There is a ton of information on how to wire things up but nothing...
Forum Discussion
pnichols wrote:MrWizard wrote:
AGM technology lends itself to high discharge rates
After all the chemistry involved easily creates current
reversing the process (charging) takes more time and will create more heat
I'm not sure you meant what this seams to say ... or I don't get it.
AGM batteries have low(er) internal resistance. That means that when less than full they accept more current per volt of applied charge voltage than liquid batteries do per applied volt. That's also why they can be recharged with very high currents when they're down aways if you raise the voltage high enough - while at the same time carefully monitoring battery temperature to prevent (the rare but possible) thermal runaway.
This low internal resistance is why my alternator can bring back to 100% charge (less than 200-300 milliamps of current flow into them) our RV's 230 AH AGM battery bank with only 4-5 hours of driving.
it means what i said
inrush and applied charge until done are NOT the same thing
so a battery can do 800amps Discharge for 5 minutes under test conditions
can you apply 800amps charge for 5 minutes, even for 1 minute ?
IF you do ? how hot will that battery get ?
why do you think that battery is rated for a 50amp charge rate, even IF it could handle a 5C inrush for a few seconds
the charging cycle takes more energy and creates more heat, than the discharge cycle
50% of 260ah = 130 ampHrs restored in 4 hrs about 22.5ah avg
possibly a 90amp ? surge rate, approx C/3
yes AGm has lower resistance, yes i love mine, but they do not do any miraculous 5C charging,
and these lifetime specs do they tell you at what DOD they are in and what the applied voltage is to reach this 5C charge rate and how long it can be maintained ?
