Trickle charging rate

[48Flatty]

I won a 4-bank Battery Tender charger as a door prize at the recent AZ road run. SCORE! It will charge 4 batteries and each bank can be adjusted to charge 6 volt or 12 volt. Reportedly, conventional batteries, AGM type, or lithium can be charged. My question concerns charging rate: I seem to remember reading that motorcycle batteries should not be charged over a rate of 1.5 to 2 amps, because of size? The Battery Tender I won charges at a rate of 3 amps. Is that charging rate acceptable or is the rate to high and will potentially damage the batteries? I would use the charger to charge AGM type batteries; three 6-volt and one 12-volt.

[tomfiii]

Is the charger rated for 3 amp? If it is that is the max it will charge, but most of the time it will be lower then 3 amps Dropping lower as it brings battery up.

[DEEBS47Chief1991]

The calculation number is 10% of the amp hours. Such as a 14 AH 12v battery should be charged @ 1.4 amps. 3 amps would be for a 30 AH battery. 1 amp for 10 AH battery.

Typically a 12 volt motorcycle battery gets charged with a 1.5 amp trickle charger.

[48Flatty]

From Deltran Battery Tender "manual": "...charges at a rate of ... 3 Amp-hours per hour." Also, " When the GREEN Charged LED is solid, the charge is complete, and the battery can be returned to service if necessary. It can also stay connected to maintain the battery for an indefinite period."

[48Flatty]

It sounds like I need to check the AH number listed for each specific battery to be charged.

[dukekleman]

48 Fatty,

I have (2) of those charger's. The one I have had in use, in our training center, for 16 seasons now. The four bank is on a rotation cycle of (50) batteries of various amp ratings for the training fleet. Technicians monitor the amperage rate of charge on this unit from 3 amp down to 0 amp depending on demand.

The second unit I have in my personal shop.
Ironically, like yourself, I also won mine twenty years ago at a motorcycle Industry banquet dinner in Daytona during Bike week.

Bottom line is these units have seen a lot of use and many different versions of motorcycle batteries without a single issue.
In my opinion, use it with confidence, not fear/concern...

Hope this helps,

Duke Kleman

[T. Cotten]

I can guess why they were giving them away, 48Flatty and Duke!

And I'll bet they have a big footprint on the bench top, too.

Back to topic, initial trickle on a fresh non-"dry charged" battery (like an NOS Dixie), or one extremely depleted, should be minimal, yet for a very long time.

But that's only what I was taught, and especially with electricity, most was BS.

...Cotten
PS: Once I was told to just put a bulb of whatever amps you want to go into the battery in series with any charger.

Like a choke. Any insights?

(It's always been a toss-up between electrics and paint for me: I hate them both equally.

[DEEBS47Chief1991]

Tom, the bulb was acting as a small resistor to lower the current going into the battery. An easy way to make a high current car battery charger into a trickle charger.