Li-ion cordless drill driver

Doesn't quite answer the question but Li-Ion is a poor battery technology to use in a power tool. Whether or not you use them much your new batteries will be fairly shagged within a few years.

Jon

Looking at the charge time of 180 minutes/3 hours a second battery could be useful.

Hmm. Li-ion

- don't self discharge. Typically 90% charge retention over 6 minths

- are light

- can deliver plenty of power per unit size

- are tyoically larger capacity than comparable Nickel chemistry

- are not toxic.

The only two downsides I have found in EXTENSIVE use is that they do not take kindly to being totally flattened, and they don't take kindly to being overcharged.Plus the price, but that is now almost comparable.

That means an hour to recharge, and NEVER flatten them. Usually the appliance circuitry will have an under voltage cutoff anyway.

With those issues in mind, they are in every other way superior to nickel.

Do degrade - increase in effective series resistance, and capacity over time, especially if kept at full charge.

Keep in fridge if not in use.

A lot less than nickel. Typcially several years.

Bollocks.

The ones in the fridge have degraded lots less.

I would say it is always worth having at least two batteries. That way you don't have to stop work half way through a job.

I think you will fond that all the decent manufacturers will sell batteries separately:

Whether or not this is true, it's still a silly idea. I'm not going to keep my mobile phone, PDA, GPS and cordless screwdriver in the fridge.

Exactly. It doesn't leave space for the polyurethane and cyanoacrylate glues for one thing.

However, last time I checked, these items had been moved to the bathroom cabinet. Quite why, I am not sure.

It reminds me of the story of the bathroom cabinet:

- The man's part of the bathroom cabinet contains, on average, 8 items.

- The woman's part contains, on average, 117 items.

- Most men don't know what 109 of these items are for.

Unused batteries only.

And only if you have plenty of room in there, so a tub doesn't get in the way.

Ah, but now we have digital cameras, we can use the space that used to be occupied by all the rolls of film ;-)

That depends. Conventional Li-ion batteries aren't brilliant for power tools, but the performance of recent batteries is considerably better than the older ones.

There is a brand new variant of Li-ion technology, out for about 18 months, based on 'nano-phosphate' electrodes. This battery type has characteristics ideally suited to power tools: Very high current/power - 2 Ah battery can supply 70A continuously Very fast charging: Full charge in 5 minutes Very high cycle life: 2000+ Very long shelf life even at high temperatures Very low risk of spontaneous combustion - considerably less than conventional Li-ion.

These are now being sold in high-end cordless tools (e.g. Makita and Dewalt). The only problem is their enormous price.