Measuring Voltage galvanic isolated

Fabian Hoppe

Hello,

I have an stack of liquid acid batteries up to 240V (2V each cell). Each cell has an volatge of 2V (120 cells in a row). I want to measure the relative(max 2V) cell voltage galvanic isolated so that the maximum voltage measured at the last cell is 2V (240V-238V). The Ground of the measuring device is 0 Volt from the cell stack. Do you have any IC you can reccomend? I hope the picture makes everything more clear. Balancing and things like that aren't needed!

Best regards

Fabian

over 3 years ago

0 Koteshwar Rao over 3 years ago

TI__Guru 56525 points

Hi Fabian,

Thanks for reaching out and for sharing your requirements.
This can be addressed in two ways as listed below.

Monitoring individual cell voltages by using individual voltage sensing isolated amplifiers.
1. You can find voltage sensing isolated amplifiers at the link below,
  1. https://www.ti.com/isolation/isolated-amplifiers/overview.html
2. This could require 120 isolated amplifier devices and 120 isolated power supply rails.
3. Can be quite expensive and consume quite some space.
Using battery monitoring devices and to monitor battery voltages, converting data to digital and then isolating using digital isolators or isolated CAN transceivers.
1. You can find the suitable battery monitoring devices at the link below
  1. https://www.ti.com/power-management/battery-management/monitors-balancers/overview.html

I will also notify the BMS team about this post so that you get the best device recommendations from the right team members. Thanks.

Regards,
Koteshwar Rao

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Measuring Voltage galvanic isolated