Small Cabin

Small Cabin Forum
 - Forums - Register/Sign Up - Reply - Search - Statistics -

Small Cabin Forum / Off-Grid Living / Basic battery charging
Author Message
# Posted: 31 Oct 2019 10:02

I have a bunch of small 4-7 ah sla batteries I use for various things. Normally I use a 1-2 amp motorcycle charger, but I have a Honda generator that has a 13.5v 8 amp charging connection. Will this kill these batteries?

I'm familiar with the water analogy where the tank is the volts, the pipe restriction is the ohms and the flow is the amps but I have trouble grasping the concept..

# Posted: 31 Oct 2019 15:53

In general (at least the 12VDC outlets I have seen on the inverter generators) they will charge a 12 v automotive battery but best only for emergency use

Checking the manual on a honda 2000 it states that "The DC charging output is not regulated. This means that the charging output does not decrease as the battery reached full charge. Check the battery voltage frequently while charging to prevent overcharging the battery". It goes on to give more warnings about overcharging. There may well be a generator out there that has a smart charger built in but I have not seen one.

Given a smart charger is not expensive I would suggest using one powered from the generator - this way you can properly set the battery type and have it go through all the proper charging stages. Or stick with the motorcycle charger.

# Posted: 31 Oct 2019 16:49

Agreed. Get an appropriate charger to plug into the generator and maintain your batteries the proper way

# Posted: 31 Oct 2019 20:55 - Edited by: ICC

Quoting: paulz
sla batteries

Those are key words. I believe charging a Sealed L-A battery at too high an amperage can cause the battery to produce the gases oxygen and hydrogen faster than the battery can recombine those into water. When that happens the regulator valve opens and oxygen and hydrogen escape. As a result the battery loses electrolyte and suffers a loss of capacity and has a premature failure.

With any SLA it is best to research the manufacturers specs and never exceed the charge rate.

# Posted: 31 Oct 2019 22:50

Thanks guys and thanks Razmichael for quoting the manual. So if you have a regulated 13.5 volt charger how can the battery ever get over 13.5 volts?
A car alternator will keep putting out its regulated output whether driven 5 miles or 50 right?

Your reply
Bold Style  Italic Style  Underlined Style  Thumbnail Image Link  Large Image Link  URL Link           :) ;) :-( :confused: More smilies...

» Username  » Password 
Only registered users can post here. Please enter your login/password details before posting a message, or register here first.