How long and what voltage does it take to go into the different charging stages?

DIY
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1

I have 2 lithium Renogy batteries to go with the Victron MultiPlus-II, which I had to configure using the PC usb adaptor, as the mobile app with the bluetooth dongle didn’t have all the settings.

The first time I charged the batteries it showed 100%, and the voltage settled around 13.66v.

Now when it the batteries are obviously charged (showing 14.something when still plugged in and then settles around 13.6 when unplugged for half hour), it only shows 87%. 87% is the new fully charged. Why is that?

Also, even though I set it for ‘charger only’, it still powers everything in the van that is plugged in, so I have to turn off the power strips so that (I assume) more power goes to the batteries.

I’m charging the van at work and charging at 7 amps. If I leave the power strips on, do the batteries still charge at 7amps, and whatever is on is added on top of that? It’s a regular 15amp power cord from an outside outlet, I don’t want to fry it, but I wouldn’t mind leaving the laptops charging, but I don’t know if that’s included in the 7 amps or gets added on top of the 7 amps I specify as the charging rate.

Also, is there any log taken so I can see what the % and voltage are at certain times when charging, what time it goes into the different charging stages and what voltage it automatically goes to in those stages?

2

When the multiplus is plugged into ac power, the whole ac side of the Multiplus becomes live and power can pass through. This is the way it is designed, all in the manual. The charger only switch tell the inverter ac/dc conversion to only work one way, ac to dc charging and not dc to ac inverting. If you have no ac appliances running then you can leave the powerbars on. However, as you are on a limited 7A supply, if you have any appliances running the Multiplus will feed these and only use what is left over to charge the battery.

Regarding your question about SOC, you need to be way more precise. Are you talking about the SOC measured by the batteries, measured by the Multiplus or by some other method. Do you have any other charging sources (solar) or DC loads (fridge?) that the Multiplus does not see. If you are just using the Multiplus SOC what settings do you have.

By the way, if you have an Android phone you can use the mk3 USB adapter with VictronConnect app, you may need an OTG cable but better than via the BlueTooth Dongle.