12 v to 12 v trickle charger

I have a 18Ah AGM battery I use as a portable 12vDC source, or as a jumpstarter for other's vehicles or an emergency additional capacity to parallel to my regular battery

Obviously, I like to keep it topped off and not worry about doing it regularly when not in use.

I make extensive use of anderson powerpoles and put one of these Ideal Diodes inside an old smoked wattmeter casing with powerpoles on eachend. I hook up the Diode in series to my 18Ah AGm and anytime my charging system's have system voltage up above that of the 18AH AGM, the latter gets fed voltage just 0.04v less than than upside the diode, and when system voltage falls below that of the 18AH agm it cannot backfeed.

https://www.ebay.com/itm/312715209707?ul_noapp=true

So anytime your regular charging system has voltage up above the voltage of the generator battery, it will charge the generator battery.

The 'Ideal Diode' only drops 0.04v across it, but I am sure some are frothingly ready to tell me/you/ the world, that they drop 0.7v or 0.4v.


These are newish products. I have passed 40+ amps through mine and actually put one permanently on the output of my Meanwell rsp-500-15 40 amp charger/power supply so that I can unplug from the grid and not have the additional fans and powermeter be powered up by the battery, without having to disconnect the anderson powerpoles. I've a third one awaiting a duty.

I also make extensive use of voltage buckers and boosters, and sometimes combo buck/boosters, but I would not use them for your intended application, if I were trying to accomplish what you are.

The 0.04v loss across the Ideal diode, makes achieving proper charging voltages a non issue. Your wiring to the diode from your regular 12v system is not even all that important, if all you want is a 'trickle'.

But your solar, holding system voltage up above 14v for hours could overcharge the generator's battery with the Ideal Diode.

The Ideal Diode goes on the positive line but needs a negative wire soldered to it as well, to function properly, otherwise it drops 0.7v and does not act like a check valve. Follow the directions.

Has anyone actually fed a 3 stage solar charge controller with an ~ 20v DC power supply instead of a solar panel? I know its been discussed often, but I've never read of anybody doing it and posting back how great it works.

Expanding on MrWizard's DC-to-DC converter idea, you could make your own charger by using a boost converter connected to a cheap solar charge controller.


150 watt boost converter from Amazon


7 amp solar charge controller from Amazon

Set the boost converter output to about 20 volts and the charge controller will prevent overcharging the battery. Connect the battery to be charged first then apply power to the converter.

Hi BFL13,

I added a place to clip on a battery charger.

I want to duplicate a trik-l-start, but with lower amperage and lower cost. I'd prefer a 3 or 4 stage charger but with DC input.

After market install !

If the battery is outside the generator anything is possible

If that is the generator battery, how do you clamp on the charger?

I had a Honda 3000 with a battery in it that died the first year because I didn't run the gen much. But the battery was inside the gen.

I never got a new battery, but I had the gen wires that go on the battery extended out of the battery compartment of the gen, where I could then attach "live" 12v from a charger, or from the 7-pin with adapter I made, or from a battery in the truck bed beside the gen.

Not too clear what your plan is, but it might be that if you have the proposed float charger on it, you don't need the battery itself. 12v from the float charger should be enough to start the gen. No idea how the remote ties in.

You will have 120v for the charger from your inverter (which has solar for its battery bank) so you don't need to ever start the gen without any 120v handy. If so, there is always the pull cord.

DROCK dc to DC converter
Many different sizes on Amazon

I used one on the safari to keep the chassis batteries topped up

Or maybe a Harbor freight trickle charger
Plug into generator connect to battery

Less than $10