The Chargepak A1 is specific to the
Pure One Mi DAB/FM Radio and works well as a rechargeable battery pack - a necessity in order to make this portable radio portable (which wasn't initially clear to me when I first bought this radio)!
The chargepak is compact and light - adding negligible weight to the radio.
It is advertised as lasting upto 18 hours (depending on use). During first use, on a full charge, it lasted nearly 20 hours on fairly low volume (position 7 or 8) with good signal strength. It was noted as being 'fully charged' because it did stop charging after several hours.
The instructions do state, "When charging your ChargePAK for the first time or after an extended period of inactivity it is recommended that it is charged for around 24 hours to ensure full battery power."
However, on recharging the battery (with the radio plugged into the mains power) it does not seem to stop charging!? After almost two weeks (yes, 2 weeks!) it was still reportedly recharging!? However, in disconnecting the radio from the mains, the battery lasted for well over 19 hours.
On a third recharge I left it charging for just a day (a full 24+ hours) before disconnecting from the mains. It was still reportedly charging. The battery lasted almost 20 hours. So it does appear to charge up OK in the stated time, it's just that it doesn't appear to stop charging or give a true indication as to whether it is charged, except apparently the first time it was charged?! But may be this is an issue with the radio itself and not the battery per se?
A must have for a portable radio and does it's job well - but remember to unplug it when you think it's been charged enough!