The trickle charger on the Mutliplus is not a true charger, it does not have a set charge voltage. It is a small circuit that is connected directly to the DC input header within the Multiplus and it contains a current limiter and a diode. The diode is to prevent the starter battery from charging the…

Hello, @pwfarnell thanks a lot for your detailed explanation, it really helps a lot. I have two questions based on that. So in your opinion the let’s say “overcharging” of the AGM batterie by the Lithium Battery via the trickle charge of MP in your example, isn’t a problem for the AGM or? Could yo…

I do not believe that an AGM will be overcharged because the rested full voltage of a lithium is 13.6V, so an AGM starter battery will be kept at 13.3V at most, which is a storage voltage, lower than the typical 13.5-13.6V float. Your idea of passing the charge current through a switching device co…

Does the trickle charger on the IP43 Phoenix Smart Charger work similarly?

[image] if this pic comes out.. this is a 150/85 victron MPPT set for 14.2v/13.4v with a tail current of 1 amp, and you can see the Starter battery stepdown/AGM voltage in a sprinter MH.. There is approx 15 ft of #14ga wire and a switch on it.. it runs 13.4v down to 12.85 ish in its daily cycles…

Hi there, Can the Multiplus-II 24V trickle charger line be used to trickle charge a 12V starter/engine battery? I would assume that it can’t and realize this thread is old but can’t find info on the Multiplus-ii 24/3000 70-50 2x120v trickle charge feature. Thanks!

@bud As the trickle charger is a direct take off from the input DC bus, a 24V Multiplus will only be able to charge a 24V starter battery. This is a good question and this has prompted me to add this note to the original post.

Thx. From your post it appears it is always enabled, correct? I think I will test it with a voltmeter.

What about if an additional 2 diodes were added in series when a lead-acid (LA) starter battery is desired to be trickle charged from a MP with a LiFePO4 house battery? So now there are 3 diodes in series, so: 3 x 0.3V = 0.9V drop at low trickle currents 3 x 0.6V = 1.8V drop at high trickle curre…

[image] OffgridSparky: What about if an additional 2 diodes were added in series when a lead-acid (LA) starter battery is desired to be trickle charged from a MP with a LiFePO4 house battery? Seems like a simple and pragmatic mod.

How does the Multiplus trickle charger work

DIY

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How does the Multiplus trickle charger work

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