Battery advice and discussion, Li-SOCl2

RE: Battery advice and discussion, Li-SOCl2

charleshaf — Tue, 12 Dec 2023 23:43:45 GMT

Would love to hear how this went!

I thought NRf9160 needed at a minimum 3.2V so even 2x1.5V batteries wouldn't be enough.

RE: Battery advice and discussion, Li-SOCl2

Torje — Fri, 13 Jan 2023 06:24:23 GMT

Thank for your reply, Kenneth, and for the resources.

After my own research, it seems Li-SOCl2 have better performance in low temp than Li-Po/Li-ion. I can't really see any better alternatives than Li-SOCl2. The rechargeable ones have too high self discharge, so long lifetime doesn't seem realistic at all. Our device, with 5+ years of battery, doesn't need to be rechargeable. Before they are empty, we'll have new products out anyway.
The Li-SOCl2 often come with different specs; either high capacity or higher peak current. I've found AA-batteries with 2Ah cap, 400mA continuous and 800mA peak, 1% self discharge per year (these are the "high peak"-type). A couple of these bad boys in parallel would give me a lot longer life time than the 5000mAh Li-Po I was considering at first, and I should be well within the specs even at cold temp. (A 1S2P-pack of these with connector is 1/2-1/3 the price of the LiPo as well.)
I prefer the AA-size to the D, as they won't build too much in height. I have space left and right, but not upwards.

But there's always the uncertainty. Choosing the right battery is no simple task. Do you (or any other community member) have any thought about this? What batteries are generally considered viable for long-term operations? (If I chose 1.5V batteries, I would need like 6 to get the right voltage and cap from the ones I've found - and this costs too much space).

It seems to me the Li-SOCl2 are heaven sent, so there might be something I'm missing.

RE: Battery advice and discussion, Li-SOCl2

Kenneth — Thu, 12 Jan 2023 15:31:45 GMT

Hello,

I don't think we have any direct experience with this, but I could find some cases that mention Li-SOCI2 (see links below in case they can provide some more information, at least I can't find anyone mention any failures). In general, Li-SOCI2 - 3.6V nominal voltage should work, but not so good performance over temp and maybe you would need a DD size to support LTE operation. But although large, this should be a possible option.

Possibly relevant cases I can see mention the battery in question:

https://devzone.nordicsemi.com/f/nordic-q-a/70455/optimal-way-of-putting-nrf9160-into-low-power-mode-without-shutting-down-the-power
https://devzone.nordicsemi.com/f/nordic-q-a/69996/nrf9160-tx-current-duty-cycle-configurable
https://devzone.nordicsemi.com/f/nordic-q-a/66557/nrf9160-current-consumption-continuous-and-peak-during-network-discovery

Hope it helps,
Kenneth