I'm wondering the same thing
I've had a number of problems with the Bluetooth counter, and have been through three which all failed. All replaced under warranty (thanks to firstname.lastname@example.org). The issue that caused my problem was down to a design fault which has now been rectified. The magnetic microswitch, unlike the one installed in the standard counter was left open rather than enclosed in a glass tube. As a result the switch was vulnerable to damage after only a short period of use. The charging circuit is still fairly basic and doesn't automatically switch to trickle mode - you have to keep an eye on it and set a timer to avoid damaging the cell, but on the plus side the revised counter is much more accurate and I find myself using it more often than not. I'm a paraplegic and use my Powerballs for rehab:
Can't think of anything else to buy!