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sv-denada asked

High DC ripple when batteries are full?

Hi,I keep on getting a high DC ripple warning, even when I only about 350 watt AC and DC combined. This also only happens when my batteries are fully charged. As soon as the charge voltage reach 28.5 volt, the ripple warning starts. I run a 24 volt system on my vessel.

MultiPlus Quattro Inverter Charger
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thatphilbrettguy avatar image thatphilbrettguy commented ·

What type of battery? I've seen some odd interactions when using LiFePO due to the way some of the BMS's work.

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sv-denada avatar image sv-denada thatphilbrettguy commented ·

Hi. The batteries are BLUE NOVA BN13V-108-1.4K units

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4 Answers
sv-denada avatar image
sv-denada answered ·

Hi Phil.The batteries are Blue Nova BN

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sv-denada avatar image sv-denada commented ·

Blue Nova BN13V-108-1.4k

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offroadflow avatar image offroadflow commented ·

You should really answer Phils question here ;)

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thatphilbrettguy answered ·

Looking at them they're 12V batteries so you're running 2 in series? I suspect one hits the max voltage and the BMS 'switches off' the charging and the system voltage starts jumping up and down a bit. I've seen this.

How do you balance the batteries? If they're out of balance this could be one of the issues.

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Murray van Graan avatar image
Murray van Graan answered ·

Running two managed batteries in series is a bad idea, since the two BMS’s work independently of each other.@ThatPhilBrettGuy is correct, one of them most likely disconnects during final stages of charging and causes the D.C. bus to become unstable. The only (possible) solution would be to fit an external battery balancer, although this is not a guaranteed fix. Rather use a battery from the 26V bluenova range

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jonathan-drewes answered ·

I get this warning as well when my single 48 pack with BMS is full sometimes. I have the SmartSolar 250/60 charging and running 2 fridges. Is there a solution or adjustment that can be made?

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Alexandra avatar image Alexandra ♦ commented ·
Drop your charged voltage by 0.2v or so. The dc ripple can be caused by the bms switching usually due to self protection.
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