Charging Cut in Half When Charging is Turned on in App

Recently put together a 12V LFP w overkill BMS for my RV. Also Installed a Renogy shunt/monitor.

In the Overkill BMS app, when I manually turn on charging, the monitor shows amps drop by half and vice versa when turned off.
Doesn't matter time of day or plugged into shore power, hot or cool. What gives?

Off:



On:

The battery is nearly full.

Browneye said:

The battery is nearly full.

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Ignore that. I had just manually reset the capacity. The accurate number is the Renogy monitor.

Doesn't seem matter the battery condition, nor the SOC. 10% or 95%. Same thing.

I guess I don't understand the question, or the configuration.
When you say 'turn on charging' - are you speaking of the BMS itself? Or the solar controller?
So when you turn it off, where would double the charging amps be going to? Is there a load the controller is feeding?

Current can only flow from high to low, so if you turn off charging there should be no place for current to flow to.

Perhaps rephrase your question - and indicate how you know your charge current is dropping. For example, at 10% SOC your charge controller will output how many amps? Then at 95% full you're saying it puts out the same current?

What is the potential of your system? Solar watts/amps? An MPPT is taking how many watts and converting them to charging current at what rate?

Battery is sitting on bench.
With a bench charger connected to P- side of the shunt, it reads 13.4V @10A. The BMS app reads 0V @0A

NOW, when I tap the "charging" button, the app displays 5A and the shunt amps drop to 5. Exactly half.

Hopefully that's a better explanation. This is all sorta new to me so I don't talk all fancy like some of you. Maybe we need a pre-beginners section. LoL

Are there any loads connected to your battery?

A.Justice said:

Are there any loads connected to your battery?

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None.

joeshmoe said:

None.

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No loads, but it doesn't matter. When I do connect a load, its the same. Half shown on the app. Half on the shunt display.

Looks like your meter just doesn't measure correctly. It does say 84watts, and that's about 8A at 12V. If bms says the battery is getting 8A then believe it. Overkill is good stuff.

Friends don't let friends buy renogy.

Or you have some kind of wiring error, loose connection, failed lug or terminal, etc.