SparkFun Forums

[Tigris]

Hello!

I recently got the OpenLog Artemis to record data untethered. I fly drones and so have a bunch of whoop batteries, specifically 1s 250mAh 40/80C lipos (nominal voltage 3.8V). They fortunately have ph2.0 ports compatible with the Artemis, and I tried plugging one in but got smoke from the connection between the battery and the board. The board still works great tethered (logging data through usbc) but I'm worried about plugging in another lipo in case I damage it. Any help would be appreciated. Thanks!

[PaulZC]

Hi @Tigris,
Did you check the polarity?
There are small + and - symbols on both sides of the board:
https://cdn.sparkfun.com//assets/parts/ ... is-02a.jpg
Best wishes,
Paul

[PaulZC]

Also, the OLA uses a 450mA charge current. See:
https://learn.sparkfun.com/tutorials/op ... view#power
"The OLA has a built-in charger too which will charge your battery at 450mA when USB-C is connected. Please make sure your battery capacity is at least 450mAh (0.45Ah); bad things will happen if you try to charge our smallest batteries at 450mA."

[Tigris]

Yes, thanks for the reply! I was ignorant and forgot to check polarity. I assumed the ph2.0 carried a standard polarity but clearly not. What's the likelihood something important is shorted, considering the main functionality of the board when tethered is fine? Wondering whether reversing the battery polarity and trying again is worth it

[TS-Chris]

Your battery may have the same connector, but I'm betting the polarity is different from what the OLA is expecting.
We recommend using only SparkFun batteries with the OLA, they all have the correct polarity to make the OLA happy.

[Tigris]

Yeah! I did make the mistake of using a battery with reversed polarity, and I found one (I think a sparkfun one) which has the correct polarity based on the wires. My question is, with the potentially damaged board, can I try plugging it in or will it make things worse?

[TS-Chris]

You should be OK plugging it into a SFE battery, it's not going to make things any worse.
Worst case it just doesn't work on battery anymore but it's not going to blow up or anything.

[PaulZC]

Hi @Tigris,
I've been studying the schematic, trying to work out where the reverse current will have flowed. I suspect it has flowed backwards through the LiPo charger IC, so you may find that battery charging no longer works. But, like Chris says, it is probably OK to connect your SparkFun battery. There is a small chance that the battery charger IC will have developed an internal short circuit. So if your battery discharges quickly, that may be the reason.
Very best wishes,
Paul

[sr205347d]

HI Paul,

I did the same thing as the OP, and let the smoke out. Yes, now that I reversed the polarity at the connector, the battery does discharge quickly. The OLA will operate, however.

Since batteries in the RC industry use the "wrong" polarity as the OLA, I think it would be good to have a warning about this in the hookup guide.

Andy