Can a daly 8s 60a BMS be connected this way?

[larfme]

See attached photo

 

[Pim57]

The bms B- needs to go to the battery direct, not via a shunt.

The shunt will generate a voltage difference when current starts flowing. And this in turn will trick/fool the bms.

So, if you want the bms to behave correctly, no shunt between B- and battery.

 

[larfme]

The bms B- needs to go to the battery direct, not via a shunt.

The shunt will generate a voltage difference when current starts flowing. And this in turn will trick/fool the bms.

So, if you want the bms to behave correctly, no shunt between B- and battery.

Thank you. That is what I was wondering. The 12v converter will need to connect to the bus bar with an SSR in between.

 

[larfme]

Can I connect two shunts one from the P- from the BMS to the 12v buck converter and another from battery- to the bus bar and connect the battery monitor to both shunts to get a total in and out amp rating?

 

[Pim57]

The battery - is connected to the BMS only!!!

From your P- you are free to go. Considder your P- as the new battery negative.

Your P- should go to the negative busbar

 

[larfme]

Yes, I understood your explanation from before. You explained it well.
The new question is can I connect two shunts to the same shunt monitor?

 

[Pim57]

Not sure what your plan is with the two shunts. Can you post a new schematic/photo?

 

[larfme]

I made a better diagram. I am bypassing the bms for bulk charging and for the Inverter.
One of the chargers will shut down at a lower voltage to prevent it from over charging the battery.
I have top balanced the LifePo4 and it is staying balanced.

 

[John Frum]

The diagram is hard for me to see but I don't think anything is protecting your batteries from the charge sources.
Do the charge sources support remote control?
If not and you get a runner you will probably ruin your pack.

 

[larfme]

There is charge protection only from the higher volt charger. The lower voltage charger should cut off before any runaway happens, I have a separate relay I might use.

 

[John Frum]

There is charge protection only from the higher volt charger. The lower voltage charger should cut off before any runaway happens, I have a separate relay I might use.

Sorry how is this charge protection implemented?

 

[larfme]

Sorry how is this charge protection implemented?

Through the BMS

 

[John Frum]

Through the BMS

Ok I see it now.
Colours are low contrast which makes it hard to see.

 

[Pim57]

The black wire from charge controller #1 should also go to the "Buss Bar -" near P- of the Daly bms.

And while doing so, change the wire color black to green, same as charge controller #2.

Nice drawing btw.

 

[larfme]

If anyone is interested in a design. I would be happy to make them one for a small fee.

 

[larfme]

It's not complete yet, but I have it setup in my off-grid garage running my deep freeze until its time to move it into the RV.

 

[larfme]

dup post