https://stream.echo6.co/videos/watch/e3d092f1-b492-454a-b8ce-bbe1ba7c8104 At around £40 for two of these "5Ah" Ryobi compatible batteries I was expecting them to be fairly low capacity. In reality they're pretty close to the claimed capacity (80%) but the circuitry they use for monitoring the cell voltage is unusual, and doesn't give me confidence in leaving them charging unattended. In the video I mentioned the potential for the 100 ohm balancing resistors to have a higher voltage across them at full charge current. Theoretically the current would need to drop to around 40mA for the resistors to safely pass the current without the risk of the cell being charged above 4.2V. Although the cell balancing seems like a good feature, I'd have been a lot more comfortable with these batteries if they had used the simpler single chip unbalanced management chip as used in the cheaper tools. It would decisively detect any cell reaching full capacity and cut the charging current off. The way the circuitry senses the voltage across the pack gave me doubts about its ability to detect a single cell going into the bypass mode. Maybe I'm just being pessimistic, but there is a lot of weird circuitry involved. All the divider resistors are critical values and even the tiniest manufacturing defect of a missing or incorrect resistor value could have significant consequences. I spent a HUGE amount of time trying to get my head around the way the circuitry worked. To properly reverse engineer the circuit would require large images, removal of components and lots of time. On a plus note they seem to have a decent cluster of 18650 cells. The temptation is to reconfigure them as a large parallel group as a chunky 20,000mAh power bank. If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:- http://www.bigclive.com/coffee.htm This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty. #ElectronicsCreators Wed, 15 Apr 2026 09:26:32 GMT https://validator.w3.org/feed/docs/rss2.html PeerTube - https://stream.echo6.co https://stream.echo6.co/client/assets/images/icons/icon-512x512.png https://stream.echo6.co/videos/watch/e3d092f1-b492-454a-b8ce-bbe1ba7c8104 All rights reserved, unless otherwise specified in the terms specified at https://stream.echo6.co/about and potential licenses granted by each content's rightholder.