Using 2 batteries simultaneously for electron

Is it okay to use two batteries simultaneously for particle electron…the one is Lipo battery which came with the device itself and the other is LiSOCl2 D size battery of 7.2 volt connected at the Vin pin.

No, the LiSOCI2 cell will just be used instantly to recharge the LiPo and then it would be empty in no time.

But the LiSOCl2 D-size battery is about 8000 mAh, while the LiPo is only 2000 mAh. So, shouldn’t this work?

Also, if this works, my further query is that will it be safe for the LiSOCl2 battery. This battery is non-rechargeable. So, no reverse current should flow into it. With LiPo connected, is there any chance of reverse current flowing into LiSOCl2?

It would work but it’s inefficient due to the DC to DC conversion/regulation from the PMIC.

Ideally, you would just use a 3.7v LiSOCI2 battery and feed that to the Li input pins and never apply power to the USB or Vin pins so charging the non-rechargeable battery never happens.

Another guy on here is doing this successfully.