Second Smartshunt for second battery bank?

[jlachapelle7]

Hi,

I have one 48V 280AH 16S LifePo4 battery bank connected to a Victron smarshunt 500A. I am prepared to connect another of the same battery bank. I read that Smartshunt has an

3.4.1 Aux connection for monitoring the voltage of a second battery. The Aux connection can be used to monitor the voltage of a second battery, such as a starter battery.

Will it be able to monitor my second battery bank, or should I just get another smartshunt. I guess I could just monitor one 16S2P as a 560Ah via one shunt ? Would that have a disadvantage?

Tks

 

[Lilikoi_Heavy_Industries]

Hi,

I have one 48V 280AH 16S LifePo4 battery bank connected to a Victron smarshunt 500A. I am prepared to connect another of the same battery bank. I read that Smartshunt has an

3.4.1 Aux connection for monitoring the voltage of a second battery. The Aux connection can be used to monitor the voltage of a second battery, such as a starter battery.

Will it be able to monitor my second battery bank, or should I just get another smartshunt. I guess I could just monitor one 16S2P as a 560Ah via one shunt ? Would that have a disadvantage?

Tks

You can't give VenusOS two different shunts as the system state of charge, you have to pick one. Is this battery bank part of your main system? Or is it a separate system that you want to just add some additional monitoring to? It sounds like you're expanding your main system (which should force it to run at about the same voltage as the battery bank overall outside of some possible sags/peaks during charge/discharge if they're not being used evenly).

You need to make both batteries connect through your existing shunt, it sounds like to me.

It's not that VenusOS will not watch multiple battery monitors for you, it's just that only one of them will represent your overall system SoC. If you don't have a main system shunt, where are you going to get that?

You can add an additional shunt and watch its numbers if you want to watch the individual banks' amps in/out and individual pack SoC. But putting smartshunts on each battery pack isn't going to add up to a system SoC, at least from what I've seen so far.

You can use the voltage monitoring line to just watch it's individual voltage, but if it's wired together to your other battery bank, that shouldn't theoretically drift far. If it's a separate system and you're using LiFePO4 where voltage is strongly correlated to SoC, the second voltage monitoring feature is awesome, sure.

 

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[jlachapelle7]

You can't give VenusOS two different shunts as the system state of charge, you have to pick one. Is this battery bank part of your main system? Or is it a separate system that you want to just add some additional monitoring to? It sounds like you're expanding your main system (which should force it to run at about the same voltage as the battery bank overall outside of some possible sags/peaks during charge/discharge if they're not being used evenly).

You need to make both batteries connect through your existing shunt, it sounds like to me.

It's not that VenusOS will not watch multiple battery monitors for you, it's just that only one of them will represent your overall system SoC. If you don't have a main system shunt, where are you going to get that?

You can add an additional shunt and watch its numbers if you want to watch the individual banks' amps in/out and individual pack SoC. But putting smartshunts on each battery pack isn't going to add up to a system SoC, at least from what I've seen so far.

You can use the voltage monitoring line to just watch it's individual voltage, but if it's wired together to your other battery bank, that shouldn't theoretically drift far. If it's a separate system and you're using LiFePO4 where voltage is strongly correlated to SoC, the second voltage monitoring feature is awesome, sure.

Yes this battery will be connected to the main system. I'm just doubling the bank capacity. Since both 48v 280Ah battery will be connected in Parallel, their voltage (SOC) should remain the same, don't you think?

 

[...]

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[Lilikoi_Heavy_Industries]

Yes this battery will be connected to the main system. I'm just doubling the bank capacity. Since both 48v 280Ah battery will be connected in Parallel, their voltage (SOC) should remain the same, don't you think?

While their voltage should stay very similar being connected, differences in wiring and cell resistance still can cause them to discharge at different rates... Current sharing videos on YouTube show this sometimes.