DC ripple lithium lifepo4 48v

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hersjoen asked Apr 22, '24

DC ripple lithium lifepo4 48v

Hey, I'm struggling with DC ripple alerts. They're okay after 20 SEC. They occur when the sun is charging. It's a 16-cell lithium LiFePO4 with 48 volts.

Settings on the shunt are:

BC:140Ah

CV: 52,7V
DF:10%

TC:4%

Charge detection time: 2m

Peukert exponent: 1,05

Charge efficiency:99%

current threshold 0,10A

Time-to-go averaging periode: 3M

I've tried adjusting down the charged voltage, but it still happens. Should I continue to adjust it down or are there other settings that need adjusting? Or perhaps other things that should be checked out?

ripple

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Answer 1 · 2024-04-22T09:59:01Z

nickdb answered · Apr 22 at 09:59 AM

Ripple has many causes, from poor connections to a battery that can’t deliver the load it is being asked to carry. It isn’t something you could usually tune out of a system.

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hersjoen commented · Apr 22 at 05:58 PM

The dc ripple warning only happens when the batteri is full. I suspect the battery BMS cutoff. So hopefully I can adjust that.

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Answer 2 · 2024-04-22T11:46:55Z

Alexandra answered · Apr 22 at 11:46 AM

@Hersjoen

Probably also charging too fast. Assuming you have a GX as that is where you are usually warned about dc ripple. And an inverter since that is what measures DC ripple.

Use DVCC and tune the charge amps down, especially if it is happening near full with full charge amps.

Settings on the shunt are irrelevant if your mppts or inverter are nor programmed correctly.

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hersjoen commented · Apr 22 at 05:57 PM

Yes, i have a cerbo GX and a multipluss 2. The dc ripple warning only happens when the batteri is full. I suspect the battery BMS cutoff.

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hersjoen commented · Apr 23 at 01:35 PM

Should DVCC be on?

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