3.7V 1100mAh Lithium Polymer Rechargeable Battery for ESP32 4pcs

Using with the Xiao ESP32C3 which charges the battery when connected via usb and run on battery when disconnected. Literally leaves nothing else to do for power management.

So I charged one up with a cheap USB-to-jst lipo charger and then powered a 600ma 3-4v COB led bar with it. That led really hauls in the current and using a 4-led battery charge indicator designed for lipo/18650 batteries I watched it immediately drop from 4-bars to 2-bars and then hold there as the light shone. Those COB light bars generate tremendous heat though and with only the aluminum backing plate and no heatsink I had to shut it off within only 10-15 seconds. The battery recovered to 4-bars almost instantly. The upshot is the battery is more than capable of driving a 600ma load which I would say is a heavy load. The pigtail wires coming out of the battery are very fine, they’re pretty stiff and fully tinned iirc, and 1.25mm jst connectors are freaking tiny but I saw nothing to say it wouldn’t work fine under heavy load. When I got them the test battery was at 3.95v and it took some time to get it up to 4.2 and for the lipo charger to declare it done. I wasn’t paying attention when I ordered them and didn’t notice these are 1.25mm jst connectors, I was expecting 2mm. I’ve ordered 1.25mm pigtails but for now I put a 2mm pigtail on one for testing. I will probably replace all of the 1.25’s with 2’s but that’ll be on a case by case basis, the 1.25’s might be an advantage sometimes.

I ordered these pair up with the following Heltec V3 cases: https://www.amazon.com/ESP32-Development-1100mAh-Battery-Protect/dp/B0DPKSKDTT the connector fits but the battery is way too big to fit in the case. In short battery works electrically the connector (JST 1.25) fits into Heltec V3 Mechanically, does NOT fit in the case I showed above The listing doesn't mention size, here it is Length: 51 mm; 2in Width: 30 mm; 1.17in

quality product. Havnt had a single issue yet

They fit nicely in my Meshtastic cases for Heltec v3 and have pretty decent capacity for a CLIENT_MUTE node

good

I like these batteries that it is compact and works for my LoRa projects. What I don't like is it never charges above 4.1v. They should charge to 4.2v (+/-.02v) but once it hits 4.1v, it literally drops to about 3.9v in about 5 minutes even when it is not plugged into anything. Now, after it drops to 3.9v, it works well and lasts about 7 hours before my project system shuts down at 2.2v. I have charged it to as much as it would to 4.1v before the built-in BMS stops at 4.1v, and let it drain down to about 2.2v and recharged it. It didn't improve and only charged to 4.1v again. Also, one of the 4 batteries didn't charge at all. It looked like a bad cable. I will continue to use these, but I may be hesitant to buy more when I need 3.7v lithium batteries for my LoRa project. Once my experiment becomes a life saving device, I will definitely look for something else. Hope this helps.

Great cell for maker projects value Tested cell performance and thermal characteristics, as rated