Hi everyone. I have a question to ask regarding a BMS system that i'm currently working on. I am trying to integrate a charging and voltage monitoring function into one system as a whole, using a DC2259A board to measure the differential voltages across 8x 3.7V 18650 Lithium Ion batteries, in 8S arrangement. However, my battery charging module DDTCCRUB only supports charging in 4S arrangement. Moreover, it cannot be chained together to support an 8S charging. I could technically get another DC2259A to support 4S2P arrangement, but the board is too expensive. Does anyone know of a 8S charging module with usb input? I can't seem to find one anywhere. Alternative solutions are also welcome!

 

Hi everyone. I have a question to ask regarding a BMS system that i'm currently working on. I am trying to integrate a charging and voltage monitoring function into one system as a whole, using a DC2259A board to measure the differential voltages across 8x 3.7V 18650 Lithium Ion batteries, in 8S arrangement. However, my battery charging module DDTCCRUB only supports charging in 4S arrangement. Moreover, it cannot be chained together to support an 8S charging. I could technically get another DC2259A to support 4S2P arrangement, but the board is too expensive. Does anyone know of a 8S charging module with usb input? I can't seem to find one anywhere. Alternative solutions are also welcome!

Hi,

USB isnt just USB anymore. There has to be specs attached to this protocol now.
What type of USB are you talking about especially with attention to the electrical current spec?

 

Using two charging modules looks like the only option to me.

 

Off the shelf charging solutions for 8S Lithium Iron chemistry batteries are not readily available because of the voltages involved.
There are battery management ics available that will handle that number of cells in series (and more) such as MAX17703 but the evaluation board for this and other manufactures similar ics are limited to 1-4 cells.
I think as @bidrohini says handling the cells as two banks for charging and monitoring is your best option.

 

Reasonably priced 8S BSM modules are available, see here:-

https://www.ebay.co.uk/itm/25318123...w1C1OUuAhGX5zZyR8DLnpUh0GA==|tkp:BFBMjoqWtY5i

You would need to use it with a boost module, increasing the 5V USB voltage to at least 30V, such as this with a specification output of up to 35Vdc. Remember that you cannot get more power out than is available from the USB source.

https://www.ebay.co.uk/itm/15440048...HRfLtF1CXMnkF4voVIhtogqcUOas|tkp:BFBM5tGWto5i