I’ve had this charger for approx 7 years so this can be looked upon as a very long term review. It’s based on the Ansmann Energy8 charger which costs £50.
Priced at £11 and encased in a stylish ‘spage-age’ design the Tronic KH980 is an intelligent charger boasting 4 independent charging slots, two of which can double up giving it the ability to charge 6 AAA/AA or 4 C/D cells. Cells can be mixed i.e. 4AAA/AA plus 2 C/D or 2 AAA/AA plus 3 C/D etc. Add in 2 seperate slots for 9V PP3 batteries and you have all the makings of a very capable charger. Very strong springs hooked up to substancial sliders push the cells up against the contacts that provide 330mA for AAA and 1000mA for all other sizes. This equates to 0.4 to 0.5C for AAA of 600-800mAh capacity and AA of 2000-2500mAh capacity. PP3s are charged at 60mA.
Operation
Each of the 8 independent charging slots has a tricolour led which gives an indication of charge status and charging progress. When batteries are initially placed in the slots the leds show the amount of charge; red for flat, orange for partially discharged and green for full. The charger now begins the charge cycle with the following led display:-
flashing red+green – refresh
flashing green – small initial charge
solid red – main charge
flashing green – charge completed (trickle charge)
flashing red – fault (battery wrong way round or voltage too low)
Results
The charger uses a negative delta algorithm to detect a voltage drop in order to terminate charging – no timers or 0.1C ad infinitum here. Over the years the charger has worked well but not without some issues. There have been some missed termination (what charger doesn’t?) and there have been problems with cells getting too hot but some of these had developed a high internal resistance. Overdischarged batteries will not charge so have to be put into a dumb charger to bring the voltage up sufficiently to fool the intelligence! If the charger has an achilles heel then it is small Ni-Cd cells. 1A for a 600mAh Ni-Cd equates to a charge of 1.7C which effectively killed a pair of old AA Ni-Cd that I’d had for years in a couple of charges. Better to make up an adapter to utilise the AAA connectors’ 330mA current. C and D cells charge just fine; their larger size dissipates heat much better than AAA/AA.
Conclusion
Am I glad I bought it? Yes. Would I buy another one? I recently did! It cost just over £10 from ebay which is seems to be par for the course for these chargers. That’s nearly their price new so if they hold their value they must be good – right?
Likes
Charges all sizes of NiCd/NiMh
8 independent charging slots
Negative delta termination
Tricolour leds give good indication of charge status
Price
Dislikes
No dc input
Charge current fixed