Can I charge batteries with a charger and generator?

MEXICOWANDERER wrote:
then argue when a professional tries to educate them. Sad Sad Sad

It's one thing if the pro clearly doesn't know what he's talking about but the one's that do know (like yourself) get the same treatment. It irritates me to no end. From my point of view, people that know their stuff are EASY to spot but it seems the average person can't (or refuses to) see the difference.

What if the OP hit the battery disconnect switch then put the batteries on a portable charger, powered by AC of course?

Decorum Ninerbikes,

Decorum

The problem is we do not have a Federal Trade Commission anymore. Companies can peddle all the fraudulent garbage they want to, lie like hell, blatantly, full page ads, and the public swallows it and asks for seconds. If it is in print, or on a website, it MUST BE TRUE. Wotta hoot, here I am an aged engineer, and some people challenge me and say "What You Say Can Not Be Fact" After all they can link on some web page and prove me wrong. America has become a nation of suckers. The ones I fell sorry for are innocents who buy into the hucksterism, and those who I do not feel sorry for buy into the hucksterism, then argue when a professional tries to educate them. Sad Sad Sad

MEXICOWANDERER wrote:
WILL


WORK

Just don't use an automatic charger. Look back through this thread and see the long post about the 33 amp power supply that is manual, works better than a transformer charger, does not lose potential like a transformer charger, and actually charges batteries in conjunction with a "s-m-a-r-t" charger.

Chargers with integral IC controls are turning many of you folks into victims. You believe what limitations these converters, impose on you is law. You are bent over with your pants down around your ankles with a sign on your back, saying KICK ME.

And you're pretty damn lucky if all the sign really says is KICK ME. It could and usually is a lot worse.

WILL


WORK

Just don't use an automatic charger. Look back through this thread and see the long post about the 33 amp power supply that is manual, works better than a transformer charger, does not lose potential like a transformer charger, and actually charges batteries in conjunction with a "s-m-a-r-t" charger.

Chargers with integral IC controls are turning many of you folks into victims. You believe what limitations these converters, impose on you is law. You are bent over with your pants down around your ankles with a sign on your back, saying KICK ME.

It depends on the brand and model of the charge controller, and the brand and model of the battery charger, and the voltage they each put out, as well as how smart or dumb, or manual they are.


My little stinking Sears Roebuck 6 amp 12 Volt battery charger that is manual is fully capable of putting out 16.0V. If I run my POS WFCO and the manual charger at the same time, the WFCO puts out nothing... it's forever trying to charge in float mode at 13.4 Volts. The manual charger overshadows it in voltage, so the manual charger does all the work and the WFCO does nothing. Which ever charger has the highest voltage will do most or all of the work in charging.

double post

X2 BFL is the master of multiple chargers

dbbls wrote:
Won't work. When your onboard generator is running your batteries will show full charge because the converter is putting power to them. A separate battery charger will read this as a fully charged battery and will not provide any power to the battery.

If that happens with that charger then all you do is turn off the converter (how to do that depends on the RV ) start the portable charger, then turn the converter on.

It depends on charging voltages whether they will add their amps and in what proportion. Say the charger can do 14.4 but the converter does 13.8 and the battery is at 12.2 at first. Also the battery must accept that many amps.

Both charger and converter will add their amps till battery voltage reaches 13.8 when the converter no longer contributes. Its amps will taper as battery voltage nears 13.8 then will stop as there is no more voltage spread. Meanwhile the charger will still be cranking out its amps to get the battery voltage to 14.4. Its amps will taper according to the charger's usual "charging profile"

If both have the same voltage, they share the amps all the way. Say the battery can accept 80a and you have two 40a chargers of same voltage. Each does 40a till battery acceptance drops below 80a then each charger's amps taper.

If one charger has slightly higher voltage then one will taper more than the other, so when battery will accept say 50a, one charger might be doing 30 and the other 20. It is proportional to the "spread" each charger has between its voltage and the rising battery voltage.

The generator needs enough watts to run all the chargers. Once one charger is doing/can do it all, you might as well turn off the other.
If two 40a chargers are each down to 20a, you can turn one off and the other will jump back to 40a and taper from there again.

Won't work. When your onboard generator is running your batteries will show full charge because the converter is putting power to them. A separate battery charger will read this as a fully charged battery and will not provide any power to the battery.