guy wrote:Latest thinking on battery life -
Do NOT store a lithium ion fully charged especially in the warm.
best option is to store it about half charged in the cold (fridge perhaps)
Worst case is a loss of around 60% capacity per year.
Guy
Where did this come from Guy?
Li-Ion don't get "memory effect", that is limited to Ni-Cad in very specific environments so is more or less a myth as far as practical use goes. Battery life is actually shortened by damaging due to overcharging until they are hot, which smart chargers are not supposed to do (fast charge about 95% and then trickle charge).
Are you sure the tip is not to store fully charged rather than do not store permanently on the charger? I guess in the latter case, especially in hot conditions the long term trickle charge is going to damage the cells.
I'm pretty sure that if you store batteries in the fridge for a long time, no matter what level of charge they have when you put them in, they will come out completely discharged. People used to deep discharge Ni-Cads by putting them in the freezer overnight to try and get them to take a charge again, it only works if the battery wasn't already damaged by overcharging though.
Obviously if your information is totally accurate, it throws into question all the previous knowledge of batteries, I am just wondering if the real emphasis should be to store batteries out of equipment, off the charger in a dry, cool place (not on top of a radiator, but not in the fridge either)???
My work laptop uses Li-Ions and runs almost permanently on mains power, I don't know what it's design battery life was but I can still get over an hour out of it and it is pretty old and abused. Using it as a desktop machine 5 days a week is almost the opposite of good battery care!
Interestingly the advice for my lead-acid based bike lights is not to stor the battery discharged, but to top it up before leaving it over the summer.
I'm really interested to find out where this new advice comes from, althogh to be honest, I doublt if I'll ever remember to follow it!
Jim