Looking for advice from the battery NiCad gurus

I have a number of cordless powertools. At this time they all use NiCad batteries but I plan on switching them over to Lithiums with time. The two manufacturers I use have both made the switch to Lithium so getting the battery packs and chargers is only a matter of cash...

My question is what is the best way to maintain the NiCads I currently have? I have several kits of multiple tools with two batteries, each will fit all tools and from two different manufactures. The first sets of batteries, from both manufactures lasted for years, always ready to use when I needed them. The second set of batteries for each set of tools are always dead when I need them and the run time seems much depleted even after charge.

Charging and use have remaind constent if not correct, I use the tool, maybe until the battery runs dead (tool will no longer do what I need) then charge and put everything away. The batteries are stored in the multi-kit installed in one of the tools. With the original batteries, the next time I usually pulled the drill, sazall, skillsaw, etc. out it would give me a few cuts, holes, etc. while I would charge the other battery. I could accomplish the task at hand. With the replacement batteries they are both close to dead, same tools, same chargers, same tasks, same logic (even if flawed), different results.

Standby times are typically 1 to 2 weeks. So my question is what is the best way (state of charge) to store NiCad batteries?

Related;just to keep the tread going,

http://www.youtube.com/watch?v=PzIlVLOH9XI

Lennart

stop using the tool as soon as you notice power loss, not until it dies. your batteries will last much, much longer. You might have to buy an extra so that you can keep working while another is charging but in the end you'll save money.

also, I use my hobby charger to charge power tool batteries when not in a hurry - the 1 hour chargers get the cells, especially the first...way too hot.

I also plugged my 1 hour charger into a timer so that when I invariably forget to return and pull the battery from the charger it doesn't get overcharged

as far as storage....if your pack is self discharging in 1 to 2 weeks you probably have a bad cell that is sucking power from good ones. I've never had a problem storing any decent nicad for longer than two weeks...

I once had replaced my NiCad pack with LiFe batteries and they worked very well as they have somewhat safer charge regimes. It was less than half the weight of the original battery too.