Li-ion safety for noob

I've finally taken the plunge into Li-ion territory and ordered a 504b along with two pairs of protected Xtar 18650's. Decided on these after studying the BLF archives, but despite much info contained in past threads I could still do with some help on a few points.

1) Is it ever (reasonably) safe to leave good quality 18650's on charge and then go off to work or to bed, or do I need to babysit them? I've read that they can take 8-10 HOURS to charge up; not sure if I'll ever have that much time to sit around the flat.

2)I'll buy a decent charger, will this make a difference? Looking at the Xtar WP2 or WP6, any other suggestions welcome.

3)I've read much here at BLF on the potential danger of 18650's but nobody seems so worried about 14500's. Are these inherently safer?

4)Is it really necessary to invest in a meter to check the charged batteries? I have no idea what such meters are called, or how to use them :/

Any help much appreciated.

1. I leave mine charging overnight, or put them on charge as soon as I get home from work so they can be done by the time I go to bed. But I wouldn't leave them charging while not home. It is OK to charge them a few hours, then unplug if you leave, then plug back in to charge when you return. They don't have to be charged all the way to full before you unplug the charger, it will not hurt the batteries.

2. Get a charger with good reviews. I have this charger from DX and it has worked fine for the month that I have used it. Protected batteries with button top won't fit in it though, but flat tops do. You just need to be sure you get a charger that will not overcharge, or charge the batteries too fast ie: Quick Chargers.

3. Not sure, but I assume all Li-ions are the same in terms of safety.

4. I would get a multimeter. They are not too expensive and great to have in this hobby. It will help in not only measuring voltage of the batteries, to ensure they are not over charger or under charged, but you can also measure current readings of your lights. They are VERY easy to use and you can get help on here to use one if you get it :)

Lensman I will answer some of you're questions. You always want to practice a good protocol when handling any type of li-ion chemistry . You mentioned you are using xtars so you may have to get the wp2 charger, they won't fit in both the tr-001 and wf-139. The wp2 is very dependable. I've left cell charging overnight by mistake with no issues ( very glad ). Yes a good or cheapo digital multimeter is a must to montior your cells voltage. Sorry for not answering all your questions, I am also learning. Let the pros chime in. you guys, useful stuff. Yes, comments from pros very welcome. Hope the words "noob" and "safety" aren't causing too much eye-rolling and gritting of teeth.. I'm trying, but it's a minefield. DX alone have all these, where does one start? And most of them have the suspiciously ubiquitous four star rating.. Undecided

This one looks like it would work fine

all you really need for flashlights is going to be Voltage (V) and Current (Amps or A). This meter will do both of those and looks to be pretty reliable after reading through the reviews.

08CivicSi, I appreciate your input here. Before I pull the trigger on your recommended meter, could I just ask your opinion on this one? If you think it might be good enough it would have three advantages over the one from DX: much quicker delivery, Amazon customer service if it proved faulty, and an English instruction manual. As a bonus it's also a couple of quid cheaper, but I honestly don't care about that; I'd gladly pay more if you think I need to.

That will work fine :). It has DC Voltage and DC Current which are the 2 things you'll be using. Though if you don't mind spending a little more, this one looks like it is built a little better.

08CivicSi, I've just ordered the Amazon multimeter. Gen 1.3, I think I'll go for the WP2, grateful for the tips. My thanks to both of you for your time and advice, you might just have saved me from being fried alive..

Here's a site I found from here that shows how to measure everything (and more) that you will want to measure. I think the site or that DIY is owned/written by BLF user HJK, so credit is to him for that :) Hope this helps!

Also here is a link from the page regarding Li-ion safety yes, HUGE helpCool. Maybe in about ten years I might be able to return the favour! Thanks mate.

You're welcome, I hope you will enjoy the WP2 mark 2 as much as I do ;-). Haha.. with the WP2 , you may sleep/leave and have a peace of mind. (Maybe)