Lithium polymer battery noise in DAQ

[jorgepullin]

Hello

I am operating a NI cDAQ-9172 chassis with a NI9234 card as a portable unit, currently powered by sealed lead acid batteries. I was considering replacing them with lithium polymer batteries to cute down on weight. However, I am concerned about possible noise from the battery management systems li-po batteries have. Anyone has experience with this?

Thanks

Jorge

[rolfk · Accepted solution]

I’m no battery specialist but it would seem to me that you are overanalyzing this a bit. The power supply input for these devices is designed to be connected to a relatively simple 12V mains power supply that is hardly a super stable DC power source but has a considerable ripple voltage. The device contains internally additional DC-DC converters to create its various stabilized voltages that it needs.

My concern would be more at environmental aspects LiPo batteries are not as robust as Lead-acid batteries and take to low and to high temperatures a lot more seriously, so that may be of concern for portable setups depending where you use them. Also the overall lifetime is usually considerably shorter unless you have a lot of charge-discharge cycles which Lead-acid batteries take more seriously than LiPo ones.

[santo_13 · Accepted solution]

I would not worry about the noise from Lithium BMS as a typical wall-adapter SMPS could be noisy than the BMS itself (there are very well built SMPS out there too). But the point is that cDAQ has internal regulators to provide the required stable supply for the chassis and cards. Don't worry about the noise from BMS unless it is a very crappy unreliable chinese Lithium pack.

[jorgepullin]

Rolf, Santoosh, many thanks!