R7 Batteries Failing (PMNN4807A) - Only 18/24 months old

Hi All,

I've got a fleet of R7's and in the last month or so around 15% of our batteries have out of nowhere gone refusing to charge (flashing red light when inserted into an Impress 2 MUC).

The MUC is running firmware v2.10, there should be a firmware update available, but I cannot find a link to it. The MUC also has a USB port directly on the back so I would like to assume that I don't need the reprogramming adaptor.

I'd be keen to know if anyone else has had similar issues (Or a fix even!) with these batteries and the R7's.

For what it's worth, I wouldn't say they're heavy use, get charged whilst turned off each night, all indoor usage too.

I can't believe that we've had this many failures for something that's not this old.

I'm not ruling out a dodgy batch as all batteries that have failed are printed with the 2435 manufacturing date.

I've tried reseating the battery 5 times to force recalibration, they do go into this state but after a few minutes they go back to flashing red.

When they are in calibration mode, the light is orange and the message on the screen shows "CAL DISCHARGE" and 0mah 0%.

I have managed to "jump start" one of the batteries a little with a 12v power supply and bring the voltage up to 6.5v and when that one goes into "CAL DISCHARGE" state, it shows around 150mah and 12% charge. But still goes into error.

I'd rather not have to keep replacing these batteries at around £90 each.