CHARGER + BMV 700, Disconnect other cables when charging ?

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21g asked Nov 13, '22

CHARGER + BMV 700, Disconnect other cables when charging ?

Hello,

The seller couldn't answer me and i couldn't find any wiring diagram for my current setup, so i'm asking this to you guys:

Here's a diagram of my setup

Question: Do i need to disconnect every other cable on the battery when i want to charge it with the IP67 charger? I'm afraid of damaging the shunt or the inverter if i leave all the cables on while charging, i'm pretty new to this.

I was thinking of using the circuit breaker and then start the charge, but still, i'm not 100% sure that it'll prevent the inverter from being potentially damaged.

(It's obvious but just in case: on the diagram, the negative cable of the IP67 charger is connected on the "LOAD and CHARGER" side of the shunt.)

(I'm only willing to charge the battery when the inverter is off.)

BMV Battery Monitor charger Phoenix Inverter

diagram.jpg (1.1 MiB)

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bunya-solar-pl answered · Nov 13, 2022 at 10:45 PM

Hi.

Your circuit looks fine to me. Should work perfectly as is. What makes you think that cables need to be re-arranged when charging?

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21g commented · Nov 14, 2022 at 12:35 AM

So, I don't even need to use the circuit breaker when willing to charge?

The fact that the inverter would get some current flow from a charger and not the battery itself made me think that, I though it'd damage it somehow, thought the inverter couldn't handle this.

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bunya-solar-pl 21g commented · Nov 14, 2022 at 02:29 AM

Yes. The current into the inverter will be a mix of battery power and charger power. The charger power will be current limited internally so for small loads the inverter will get its power from the charger but once its needs more than the charger can supply it wiil come from the battery.

No need to use the circuit breaker to turn the inverter off.

Does the fuse have an on/off function as well as being an overcurrent device? If it does you could remove the rotary switch from the inverter supply line as you don't need two forms of switch in the one line.

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21g bunya-solar-pl commented · Nov 14, 2022 at 02:22 PM

Thanks a lot for these pieces of information!

And yes, indeed, the fuse does have an on/off function, don't really know why i added a second switch, beginner mistake i guess aha, will remove it.

many thanks.

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Answer 1 · 2022-11-14T04:26:17Z

kevgermany answered · Nov 14, 2022 at 04:26 AM

@21g

The neg from the charger should be on the load, not the battery side of the shunt. Otherwise the charge current won't be recorded and the BMV won't show correct state of charge.

As said by @Bunya Solar PL no need to disconnect/shut off inverter while charging.

If you want a decent battery life, don't use more than 50% of its capacity and keep it fully charged.

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21g commented · Nov 14, 2022 at 02:23 PM

Yes the negative is already on the "load and charger" side on the shunt, thanks for your answer!

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