I've been doing some preliminary research on this should I decide to take the dive to li-ion. However, it seems to be hard to find a decent cheap charger for protected 14500's. Most of the dx ones sound pretty dangerous. The Xtar mp1 won't fit a 14500 and the wp2 I read wasn't recommended for the smaller cells because the current is too high at termination. I definitely want a charger that for sure terminates correctly and I don't want to spend a large sum of money.
On the topic of batteries, are the flame trustfires pretty much the way to go for budget? It sounds like they are the best of the dx options. What's the next step up in quality level from them?
This one is a little scary, but it is cheap and will use a low enough charge rate for 10440 and 14500 batteries. I've had one for a year without any problems. It will tide you over until you get a hobby charger . . .
For what it's worth, I've been using the Trustfire TR-001 for 14500's for awhile now. I've got 2 of em, one terminates exactly at 4.2v, the other at 4.24v. Just something to watch out for.
The reviews I've read of the WF-139 is that it doesn't actually temrinate. The current just gradually decreases and then the green light comes on. That doesn't sound like something I want. i also heard that protected cells are a tight fit in the WF-139 which is another potential problem.
No matter what charger you use, you should take the battery out when the light turns green. Even chargers that might overcharge by a few hundreths of a volt are easy to just stop before the light turns green. The charge tapers off significantly, so you have plenty of time to measure the voltage of the battery and see if you're happy with the charge.
I consider this charger http://www.dealextreme.com/p/trustfire-tr-001-multi-purpose-lithium-battery-charger-12594?r=43033281 as the best in the budget class, due to its price and performance. I have 2 of them from more than a year, no problems at all, good algorithm... Recommended
the TR-001 white or later back ones worked well for me. I had one I used for over a year and never charged over 4.21v. That said, I would always monitor them when the light turned green I would pull them.
I still think cheap chargers are not a good way to charge batteries.
I don’t trust the charging regiemes, and the lack of true cc/cv control. I was reading about the xtar chargers, and I was wondering if anyone has confirmed that they do terminate properly? If the do, then it’s maybe worth the extra cost?
What does scare me is the fact that they describe a “triple charging regime”, cc/cv/tt. Tt standing for Trickle charge… :o. The words trickle charge and lithium usually go together with images of fire, explosions, burnt down stuff.
I hope by that they mean that the charger will charge the battery once it drops in voltage, and the it never exceeds 4.2v, but again, this can only be tested with the product in hand, descriptions are suggestions at the best of times.
So yes I was wondering if anyone had experiences with the xtar range.?
The reviews I read of people who tested them say that they do indeed terminate correctly. The wp2 does have a monitoring feature, which uses an exceptionally low current of under 1mA, but the voltage neds to drop pretty far before it starts to charge the battery again, which won't be a probelm unless you are going to do something stupid and leave the battery on the charge for several days. Obviously i don't own one myself. I'm hoping old4570 jumps in and gives us some info.
One more question, since I read that the wp2 has the flaw of terminating when the current is a rather high 200-300mA and that this was bad for smaller batteries like the 14500 and 16340. Why would that be bad? It sounds like otherwise that the xtar would be the perfect low cost alternative to the Pila.
A bit above the usualchargers price but WP2 from xtar can do that. On top of that it is a decent dual bay charger i was using also for 16340's with a ball bearing as a spacer. :P
It's a nice unit i can easily reccomend. I will check the terminating current on my unit as i think it's rather strange being 200+mA.
I use this one like "travel charger". Probably not the best choice but it's really cheap, charge different battery and stop the charge when the battery is fully charged.
So why is it that all our cell phones are run off li-ion and they seem relatively safe, with exception of occasional bouts of factory defect creating bad batteries, and that there is so much trouble with these li-ion cells used for flashlights? Is it that the control electronics in a phone are so much better than what they put in these chargers? There are so many ultra cheap cell phones out there without a problem. Is it that hard to make an ultra cheap charger that can run safely?
So why is it that all our cell phones are run off li-ion and they seem relatively safe, with exception of occasional bouts of factory defect creating bad batteries, and that there is so much trouble with these li-ion cells used for flashlights? Is it that the control electronics in a phone are so much better than what they put in these chargers? There are so many ultra cheap cell phones out there without a problem. Is it that hard to make an ultra cheap charger that can run safely?
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There are a few reasons for this:
- Cell phones, chargers, and their batteries are designed from the ground up as a complete system. All components are matched, as in the charging circuit is matched to the spec'd battery.
- Cell phones do not punish li-ion batteries the way a hard driven flashlight can. The current draw is much lower.
- Financial incentive: When a large company starts designing a new phone, they are expecting to sell millions of units. There is a huge financial incentive to have a safe, reliable power system. In this scenario, the cost for good R&D is spread out over all those units sold. I don't have any hard figures, but I imagine the number of flashlight chargers sold is only a fraction of what one brand of cell phone is. Having said that, there are well designed chargers out there for flashlights, but the cost is substantially more.
Lastly, I think there's a good bit of F.U.D. surrounding inexpensive li-ion chargers and their use. Some folks insist on only charging there cells while inside a brick lined bank vault with 2 fire extinguishers and 10lbs of sand at the ready, while wearing a 100cal arc blast suit and staring intently at the red light waiting for the merest hint of green to appear.
Phones have the charger chip within them. These charger chips are not cheap (up to a dollar or two of when bought in the millions) but they provide proper CC/CV regulated charge, charge monitoring, and all the digital interface shizz bang. And their no bigger than 3mm square (1/8" square) I dont know why these cant be used in chinese chargers, but its almost literally a single chip item. I think it still comes down to cost, these prob cost a little more when bought in the thousands. (couple dollars)
I think the answer is that lithium-ion batteries in flashlights aren't causing nearly as many problems as the Henny Penny's out there tell you. Yes, you still need to be careful, but a "cheapo" charger that doesn't use cc/cv can still charge a battery safely for hundreds of cycles.
I also agree with Match that a phone or iPod is designed as a system and they know the loads and the battery that will be used.
How about using the xtar mp1 with a spacer? Where can I find a cheap spacer and is using spacers considered more dangerous or just annoying? The mp1 is low curent so they would take longer to charge but it shouldn't be too bad for a 14500 cell.
And can someone answer the question on why it is bad for a charger to have fairly high current on termination? Or is it just a matter that the battery may not be at full capacity and so they won't last as long.
The Pila is the only 'recommended' charger I own (not budget @ ~$46), and some say that even it is not 100% CC/CV compliant. I have several cheap chargers that terminate at about 4.2v. The termination voltage can vary depending upon the age/health of the cell. I use them for smaller cells that should not be charged at the Pila's 600ma charge rate. I charge them while reading or sitting at the computer, which lets me remove them as soon as the light goes green.
The other factor to be concerned about is charge rate. Most cells are recommended to be charged at no more than 1C and I try to charge at .5C or .6C. The Trustfire red/black/flames are rated at 900mah, but cells are commonly over rated, especially the smaller ones. I don't use 14500 cells, but if I did I would want a charger that would treat them gently by charging them at 500ma or less.