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Charging starter batteries-alternator vs 240V charger

Posted: Sun May 31, 2009 2:03 pm
by TheOtherLeft
I was thinking the other day whether alternator or 240V multistage charging is better?

Since alternators only charge to about 80% SOC wouldn't plugging a mains charger to the battery every now and again be beneficial? Since the mains charger is multistage and hence achieving 100% is possible would this extend the life of the battery? Or is a pointless exercise since the next time you drive the alternator would only charge to 80% anyway and hence negate any benefits of the multistage charging?

Re: Charging starter batteries-alternator vs 240V charger

Posted: Sun May 31, 2009 3:08 pm
by -Scott-
TheOtherLeft wrote:Since alternators only charge to about 80% SOC
No. This is a myth, created by an accurate statement being taken out of context and often misquoted. An alternator is capable of charging to well in excess of 95% SOC.
TheOtherLeft wrote:wouldn't plugging a mains charger to the battery every now and again be beneficial?
It won't hurt, and, under certain circumstances (such as those under which the XX% SOC comment is applicable), will be beneficial.

If you want to do it, go ahead. Personally, for my circumstances, I wouldn't bother.

Re: Charging starter batteries-alternator vs 240V charger

Posted: Sun May 31, 2009 9:35 pm
by drivesafe
If you drive your vehicle like a shopping trolley, continually doing only short runs, then you may have a battery that is not fully charged but this is not because your alternator can’t fully charge your battery, it’s because your alternator has not been give enough time to recharge the battery.

In this sort of situation, an occasional charge with a battery charger can prolong the cranking battery life span.

If on the other hand, you driver for more than 15 minutes at a time, your battery should be fully charged.
-Scott- wrote:If you want to do it, go ahead. Personally, for my circumstances, I wouldn't bother.
Couldn’t put it better!