2021-05-03 Refreshing rechargeable batteries
With lots of devices running on rechargeable batteries including toys with motors and lights we have accumulated quite a number of rechargeable batteries in our house. Some of them have been around for ages and others are more recent. With the amount of batteries varying per device (we have seen 1,2,3,4 and 6 batteries per device) it's good to charge each battery individually as they may have different residual charges and always charging them in pairs when one is not as good will only make the difference worse. But the charger for individual AA/AAA cells we have also wants to charge the batteries quite fast and will abort as soon as one cell doesn't accept the charge. More and more batteries got rejected this way, even relatively new ones. The solution: a smart charger that has adjustable load current, can refresh a battery that has problems accepting charge and measures the charge in the battery. And does this for 4 batteries at the same time. I gathered batteries from all kinds of places (quite a collection) and started charging and measuring all of them. A number of batteries got rejected because even a "refresh charge" ended at less than 50% of the original capacity. Those batteries will be handled as chemical waste. The others with enough capacity left are now all in the big box of charged batteries. Most of them will not keep their charge until the moment we actually need them, but it's good to know they are usable. I bought the https://www.conrad.nl/p/voltcraft-ipc-3-batterijlader-li-ion-nicd-nimh-10440-14500-16340-16650-17355-17500-17670-18490-18500-18650-1403321 from Conrad which has only one downside: the fan is somewhat noisy.