3.7V 4000mAh Battery 606090 Lithium Polymer Ion Rechargeable Li-ion Li-Po Battery with 2P PH 2.0mm Pitch Connector

This is a drop in replacement for the battery on a Keychron K4. Great battery so far, no issues whatsoever. Has the correct connector and easy to install.

Battery seems to work fine

I was greatly surprised and delighted that I could swap out the rechargeable battery on a product I really liked which I thought might be only fit for Landfill. The price was reasonable, relatively easy to fit and delivered quickly. Would definitely recommend.

Works, thank you, replaced old blow up battery with this one with ease. Fast shipping too, thank you.

The battery is faulty and will not charge. I initially used the original PSU supplied with a model helicopter (fitted with this battery), this failed to charge the battery. To eliminate any problems with the original PSU I then used a test bench PSU set with the recommended settings of 4.25V dc, 250mA, this PSU indicated that the battery was not drawing any current, i.e. 0mA.

Bought to replace expired 8yr old battery this one has a higher mAH so should last longer as I only use solar to recharge it. Good value and long life.

Absolutely what I was after - the battery in our rather outdated 'smart meter' had given up so I looked for a possible replacement. I was surprised to find this one so I was happy there may be a solution rather than having to pay extortionate prices for a whole new smart meter set up. I simply re soldered the new battery in and et voila it's repaired

My Heltec t114 only charges it to 80% not sure if it's the device or battery. Haven't tried it in a different device or tried a different battery in the Heltec yet will edit once checked.