Multiplus 12/800/35 charging current very low

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marc-kelly asked Feb 4, '24

Multiplus 12/800/35 charging current very low

Hi there,

I have a Multiplus 12/800/35 connected to a 12v 346Ah LiFePO4 battery. I've configured the charger/inverter for max 15A charge current and for the LiFePO4 battery. The remote panel is set for 10A max charge current as the 240v AC-in is connected to a 10A circuit. The BMS is set to allow 60A charging current.

I don't ever see more than 2A draw from the AC source when bulk charging. I can't understand why. I've used VEConfigure to reset to factory defaults except for the max charge current and battery type settings.

How can I troubleshoot this? I'll be on site (on the boat) on Friday and can take logs.

multiplus ve.bus

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Answer 1 · 2024-02-04T23:35:36Z

marc-kelly answered · Feb 04 at 11:35 PM

Anticipating some questions based on some other threads:

- the symptoms are the same with power assist on or off

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Answer 2 · 2024-02-05T00:34:41Z

Guy Stewart (Victron Community Manager) answered · Feb 05 at 12:34 AM

Hi @Marc Kelly,

The max charge current that is set in VE.Configure is in DC amps. It sounds like you set this to 15A DC at 12V. That can be supplied with 1A at 240V AC.

That is what is limiting the system.

Change that setting to 35A (the maximum of that inverter charger) and you should see the charging power increase.

The other setting you want is the AC input current limit - you want to keep that to 10A which is the limit to your supply.

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Answer 3 · 2024-02-05T00:36:03Z

marc-kelly answered · Feb 05 at 12:36 AM

Thanks Guy. Wow. Don't I feel a bit dumb.

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Guy Stewart (Victron Community Manager) ♦♦ commented · Feb 05 at 12:37 AM

I can confidently say you are not the first person to get confused by which of those settings is in AC and which is in DC :)

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marc-kelly Guy Stewart (Victron Community Manager) ♦♦ commented · Feb 05 at 03:26 AM

Can I confirm, when I say I've set 15A as the max charge current I mean I've set the variable at 2. below to 15.

Is that value the current limit in DC amps?
For completeness, I haven't changed anything from the defaults on the charger tab. All the settings on this tab, as below, are configured per whatever happens when I set LiFePO4 at 4. and 11. below:

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Matthias Lange - DE ♦ marc-kelly commented · Feb 05 at 05:00 AM

2. On the first page literally says "AC input current limit" with that setting you say the MultiPlus how much AC current it is allowed to pull from the grid.

And with the remote panel you also adjust the AC input current limit NOT the charging current.

10. In the charger settings is the max. charging current in DC amps.

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