question

thunderpuppy avatar image
thunderpuppy asked

Multiplus 2x120 not Charging Batteries via Portable Generator

Off grid RV with 50 amp service. Multiplus II 12/3000 2x120v. Won’t charge batteries with generator running, 125 volts are detected on line 1 and line 2, but 0 amps (And only 0 amps, it‘s not like it starts to charge and then quits. Multiplus lights are “Mains On” and “Float” (some times Absorption instead of float). No other warnings/errors. Generator is a Cummins/Onan P4500i inverter generator.

I‘ve gone through all of the settings changes as outlined in the Victron generator faq to no avail.

The generator is attached to the Victron through a 30 amp to 50 amp dogbone adaptor.

I have a theory that the issue may be related to the fact the generator has a floating neutral. Does this make sense?

I’m thing of bonding the neutral and ground at the generator and seeing if that helps. Thought it best to seek others expertise so that I don’t let the magic smoke out of anything.

Anything else to try not already covered in the FAQ?

I have access to a second portable generator, also with floating neutral, but different brand. I’ll give that a try for sh*ts and giggles, but am expecting the same issue.

Generator
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3 Answers
Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·

Hi @Thunderpuppy,

It might be something specific to the 2x120 and the phase configuration of the generator.

Have you read these other community posts on the same topic? There are some suggestions in there. I will also add those links to the generator FAQ.

https://community.victronenergy.com/questions/128941/multiplus-ii-2x120-with-onan-5500.html

https://community.victronenergy.com/questions/110548/multiplus-ii-2x120-generator-compatibility.html

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thunderpuppy avatar image
thunderpuppy answered ·

Shouldn’t be a phase issue, only one hot coming from generator (30 amp). Dogbone 30 to 50 adapter guarantees L1 and L2 are in phase on the 50 amp side. The links provided were interesting reading, much appreciated.

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thunderpuppy avatar image
thunderpuppy answered ·

So I bonded the neutral and ground at the generator, I don’t think it made a difference, but I did notice something else. I’d been using VictronConnect to modify the settings on the multiplus, but this morning, I decided to look at the settings through VE.Config, and noticed that the battery type was not set to Li ion. I tweaked that and uploaded, rebooted, waited the few minutes it takes to get things sorted and…Success! The multiplus is now charging the batteries.

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