There are rapid chargers and slow chargers. Does it make any difference in the output performance of a battery if it's charged 'slowly' or 'quickly'??? In other words, will it work the same either way and last just as long on a charge??

What about the life of the battery. Will quick chargin it shorten the life more so than slow chargin?? :(

I have come across many batteries dried out and ruined by long term charging using so-called "fully automatic" chargers.

All automotive chargers, even those equipt with LEDs and accompanying symbols, simply regulate to a fixed voltage of around 14.4v.
They will certainly charge the batteries fully, and may even tell you when the batteries are fully charged with an LED, but if you are not there to supervise the process, they will just keep pumping away at 14.4v, until they are either switched off, or they have turned your batteries' water component into a cloud of hydrogen and oxygen, and they have effectively become open circuit. Slow is best, rapid charging can damage plates with gas pitting.

Originally posted by Old Scout
Slow is best, rapid charging can damage plates with gas pitting.
What about a batt. like an optima? Does the same hold true. I have seen this debated here many times with no difinitive answer. I always slow charge my optima before a trip.

What I really was interested in was whether a battery would perform the same and last as long (per charge) if it was 'Quick' charged or 'Trickled'??? And would the same apply to all batteries from Nimh AA's to big ol sealed batteries, like an Optima, for example??? Any experts out there??
:beer: :D:D

Modern chemistry batteries a lot more forgiving than those of years ago, but a standard lead-acid battery is the most forgiving of the types we use daily. The one weakness that lead-acid has is that during deep discharge periods the plates will become covered in lead and the battery will never be the same again. Sealed lead-acid batteries (or gel-cells) use a saturated media which can be very sensitive to over-charging and high temperatures (which cause out-gassing). The older small NiCad batteries were very sensitive to both charge and discharge conditions. If they were charged slowly and discharge slowly then crystals would grow across the plates and kill them (this is known as sulfation). Either a fast charge or fast discharge was required to prevent this condition. Another side effect known as "memory" was also a problem, NiCads need to be nearly fully discharged before being recharged to prevent damage. In general if these were charged quickly they would maintain a higher voltage longer into the discharge cycle, if charged slowly they could reach a higher capacity although at a lower voltage. NiMH and LiIon are the new chemistry which we use today, they have greater energy density and longer operational life but are more expensive and require a more complex charger. Many of these packs have smart electronics inside them to act as fuel gauges and continously monitor how much power is used. Charging these type batteries fast will dramitically decrease their life. But I'll try to stop rambling now...

One thing many people don't realize is that we "fast charge" our batteries every time we start our cars. I don't think many consumer rated automotive chargers are capable of 60-100Amps like our alternators are. But if you're bringing a battery back from a deep discharge then slow is always better. Since your question encompassed such a large field there is no generalization about charge time vs discharge time.

(feeling uselessly wordly as always) CP8071