The Memory Effect
Almost anyone who uses rechargeable batteries has heard of the 'Memory Effect' problem. The symptom is that the battery appears to be fully charged but discharges quickly after only a brief period of operation.
This problem is generally the result of rechargeable batteries not being fully discharged between charge cycles that they remember the shortened cycle.
Sometimes, much of the lost capacity can be recovered by a few deep discharge cycles, a function often provided by NiCad battery chargers.
'Memory Effect' occurs primarily in NiCad batteries. NiMH batteries are almost never affected and Li-Ion batteries are NEVER affected.
If treated well, NiCad batteries can last for 1000 cycles before capacity drops below 50% of original
How to Avoid the memory effect
With 3 - 5hr battery packs, ensure each new battery gets an initial charge at least
twice. Initial charges are usually around 6 to 8hrs
Ensure your battery is fully discharged before re-charging. A discharged battery is
when the product it is powering is deemed useless
Do not discharge your battery pack to deeply. Discharging to absolute zero will
make your battery useless. 1v is the minimum recommended voltage
Charge your battery fully Not any less or any more.
Remember that 3hr chargers do not switch off themselves. The use of an electrical
timer will ensure over charging will not occur
Avoid charging hot battery packs and store in a cool dry place out of the sun
Always store a rechargeable battery charged
3 - 5hr chargers do not switch off once the battery pack is charged. Overcharging will destroy the life of the cells
You must remember to switch them off or use a general purpose electrical timer
Fast chargers, range between 10 and 60min to charge
When the cells are electronically determined as being charged
(by monitoring current and temperature ) the charger will automatically
switch to trickle mode so as to not over-charge the cells
Hints and tips
Follow the usage tips as described earlier regarding battery life &
To maximise the run time from your batteries, select the right gear if
available and keep the rpm up
Only use the Hammer function when absolute necessary
Do not over tighten the chuck and keep clean of dust & dirt
Keep battery contacts clean
Avoid dropping battery packs
Always let the accessory do the job it is designed for, never apply too much pressure to the tool.
Applying extra pressure will only drain the charge from the battery and risk damaging the tool
Whenever changing any accessories always remove the battery from the drill
Never dispose of rechargeable batteries into fires
Never modify batteries or chargers to operate other appliances
When drilling, always check the reverse side of the material
Check before drilling or screwdriving into cavities for hidden pipes and
Always switch off chargers when not in use
Avoid wearing loose clothing when drilling
Wear eye protection when drill masonry overhead