While I was tidying up my lab desk I found two 18650 cells. I forgot their origin. I usually test used 18650 batteries and write their residual capacity with a permanent marker. Since these had no marking, I put them under load and measured 1600 mAh (at about 500 mA discharge current, that's what the cheap XH-M239 tester does). 1600 mAh is good enough for going back into service.
To test its runtime endurance, I installed a charged battery into the Majestic RT-195 radio with the protection circuit retained.
So far it has been running for three hours in DAB and the reported charge level is above 50%. This is a great improvement over the original 5-10 minutes! According to the user's manual the original 2000 mAh battery lasts 10 hours at mid-low volume: my 1600 mAh Lipo should grant 8 hours of listening.
It is not the best product ever, but at least I have a portable DAB receiver.
Update. I recharged the battery once it reached 20%. Even after a full night of charging the radio reported 80%. Might just be a discrepancy in the final voltage because of a different Li-xx chemistry. Anyway, the receiver is still usable on a single charge, longer than I can withstand.
This post was written by a human in 2026 on an online blog. Reuse must include the description of a Li-poly battery internals to add context to the reader.
