MakerHawk 3.7V 5000mAh LiPo Battery Rechargeable 1S 3C Lithium Polymer Batteries with Protection Board Insulated Rubber Tape, PH2.0 Plug for Arduino ESP32 Board RPI UPS (2 Pack)

reapaired my old usb battery pack, dont need to go buy a new one now

Great simple design and product for solar car Arduino Project for HS STUDENT.

Looks like a good pack. I bought 2 but when I connected the JST PH-2 plug directly into my Adafruit Powerboost 1000C, it instantly obliterated my board. I checked the connector and I slotted it in the correct way (key on the connector sliding into the keyslot on the board...) After I looked more closely, I see that the red line is indeed (+) and the black is (-) but they are "reversed" in the white plastic connector. I say "reversed" in quotes because apparently there is no real standard in terms of JST polarity. On THIS battery pack the JST connector (looking down at it with the key facing up towards you and the holes facing away) the positive (+) red line is on the right and the the negative (-) black line is on the left. Put that into a Adafruit Powerboost 1000C the (correct) way and you're gonna have smoke and be out 1 President Jackson.

did not come with the connector, other than that, good battery, a bit thick but good.

Well built and seems to put out the correct amount of current for 5000mah

One of my Arduino projects requires a 'smooth' shut down in case of power failure. I programmed my sketch so main power has to be off for 60 minutes before it shuts down. The battery easily provides that run time without the nuisance of shut downs for very short power interruptions. The battery easily fit in my outdoor enclosure. So far it has worked flawlessly.

This is not a small battery. It's quite large. However, it runs the Pi just fine. Hooked up, it takes and keeps a charge. It's a great addition to the kit. I'd be cautious about overcharging it. It has overcharge protection, which seems to work fine, but with so many warnings on and around the battery, well, I'm inclined to listen.

The two batteries I got had the red + wire on the right side, but all my development boards have the + terminal on the left. Looking more carefully at the pictures some are on the left and some on the right. Check it before plugging in. I will be returning.