Hi there, I am new to here but just a thought, if buying cordless lithium battery range, seems like bosch lithium batteries do not have cell balancing circuits internally. Basically the charger considers the battery is fully charge when the battery start to heat up. Newer generations seems to try to correct the previous lithium battery generation but still not as good as it should be. Balanced charging is very important for lithium batteries if you are heading towards that direction.