BMS DALY soc problems

[chrisandbev]

hi,
i have fully charged my 2 sets of 4 cells, they are all balanced and all cells are at around 3.194.

i had them set up in pairs so as to get 400amp hours, i could not set the soc it stayed at 0%, so i changed the cells around to make then 200 amp hours just 4 cells and found i could still not change the soc. I did this to both sets with no joy. I must be doing something wrong or the daly smart 200amp bms is not working.

can anyone advise as to what i should try next to reset the soc

many thanks

 

[Lenny HB]

As you are talking about balancing cells I assume you have Lithium batteries?
Raul may be able to help.

 

[Raul]

It quite sure what you try to do; the 0soc sets itself when you empty the cells. You need to have them full first, so it has a ref point. The balancing is important at the top from 3,4-4,45 up. You can not balance at 3,1-3,2v. That’s not balance.

 

[Raul]

What is your arrangement , 2P4S?

 

[Wissel]

Same as Raul says. See what your BMS is set to balance at (mines 3.4v), balance the cells, then it should reset the SOC to 100%.

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[Two on Tour]

hi,
i have fully charged my 2 sets of 4 cells, they are all balanced and all cells are at around 3.194.

i had them set up in pairs so as to get 400amp hours, i could not set the soc it stayed at 0%, so i changed the cells around to make then 200 amp hours just 4 cells and found i could still not change the soc. I did this to both sets with no joy. I must be doing something wrong or the daly smart 200amp bms is not working.

can anyone advise as to what i should try next to reset the soc

many thanks

If you have not set the cell volt high protect in the app "Parameter Settings" and not fully charged the battery, then the BMS will not have a reference point of what the 100% SOC is.

 

[chrisandbev]

Same as Raul says. See what your BMS is set to balance at (mines 3.4v), balance the cells, then it should reset the SOC to 100%.

so from what everyone is saying i should top balance the four cells and then reconfigure the cells 4's and set the cell volt high protect parameters to 14.6 is that correct

 

[Raul]

You have 8 cells? And you want one 12v bank? Then 2P4S. Each 2 cells in parallel becomes one, with double capacity. Charge first to 14,4 -3,6, to allow the cells to balance. Increase top voltage as the pack gets balanced, few cycles.

 

[chrisandbev]

You have 8 cells? And you want one 12v bank? Then 2P4S. Each 2 cells in parallel becomes one, with double capacity. Charge first to 14,4 -3,6, to allow the cells to balance. Increase top voltage as the pack gets balanced, few cycles.

hi,
i thought i may of not fitted the cells correctly when there was a problem with the soc, thats when i changed them back as if i only had 4 cells and this didn,t sold the problem, when i get in from work i will re set them to 2p4s and then fully charge them with the bms set to 14.4 and hope that will then sort out the problem,
i have also thought of getting another bms so that i can have 2 1p2s and connect both in series to see if that helps

 

[Two on Tour]

Is your BMS a 4S or an 8S ?

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[Raul]

Chris, if these are new unused cells you want the cells at least same voltage across all. Put all cells in parallel, no charge, with temporary wire, and let them for a day or two. They will equalise in voltage. The re configure as you like.

 

[Two on Tour]

You will need to set your MPPT and your EHU chargers to a full charge voltage that will not trigger the cell high voltage protect of your BMS, otherwise the BMS will shutdown with you losing all battery power,
and this usually requires jump-starting the BMS to switch it back on. Been there and done it.

 

[chrisandbev]

Is your BMS a 4S or an 8S ?

the bms is 4's

 

[chrisandbev]

Chris, if these are new unused cells you want the cells at least same voltage across all. Put all cells in parallel, no charge, with temporary wire, and let them for a day or two. They will equalise in voltage. The re configure as you like.

hi great idear they are only a couple of months old, this is my first time making a battery bank/box. the idear is to make it so i can run a separate inverter and another 12 volt supply without having to change the van setup and i hope to be able to move it from van to van if i change vans. i will try to equalizes the voltage over the weekend

 

[Two on Tour]

the bms is 4's

If you are going to stick with 8 cells, then I would buy an 8S model and flog the 4S rather than run 2 x 4S BMS's. A 4S BMS should be fairly easy to move on.