Lacuna Mk4... charging error... batteries

Huevos

I've been trying to get to the bottom of the "charging error" thing since I bought this meter. It would seem that the battery pack contains some sort of thermal cut out to stop the battery from destroying itself should it get too hot whilst charging. What happens is when the battery gets too hot it goes open circuit until it cools down (about 15 minutes). "Charging error" is displayed until either a soft reset is done (hold on/off button down until message disappears...about fifteen seconds) or all power is disconnected from the meter (battery and charger).

The yellow plastic meter case has no provision for the battery to cool down (no ventilation holes for example) so the only way for it to cool down is through the sealed plastic case (not very effective). What I have found is the battery will charge normally without showing the "charging error" message if the meter is charged without wearing its black protective jacket, but if the protective jacket is not removed the "charging error" occurs every time. I think that even when the error doesn't occur the battery is becoming unnecessarily hot which I'm sure must be doing long term damage to the battery. For this reason I am thinking of drilling some ventilation holes above and below the battery pack so some air can circulate through the case and from now on I am always going to remove the black protective jacket whilst charging.