I’d like to get a protected battery pack with easily removable holders for a bunch of unprotected cells I’ve got. There have been numerous occasions where I wanted to charge a phone or power USB speakers but didn’t have easy access to a plug and didn’t want to leave them in a car.
Do any of these battery pack/holder things allowing charging (and protection) of the cells inside as well?
Hjk does very comprehensive tests on batteries, chargers, power boxes and the like. You can find quite a few tests on power boxes here:
http://www.lygte-info.dk/info/indexUSB%20UK.html
Some do provide under voltage protection and most allow charging of the cells within. Not sure if any provide a separate carrier for the cells though.
John.
I had countless of these “DIY powerbanks” that come empty to put your own 18650 battery, and what I found out after several months of testing is that single cells units works best. The multi-cell units that I own in general do not work good enough as a battery charger (Only draws 1A to charge 4x18650 at the same time, takes a whole day) and somehow are not as efficient as a power bank, let’s say 45Wh worth of battery power to only deliver 20Wh.
Personally I have this one in my car with a 4-bay 18650 holder:
C3 with a cree flashlight head
It does a great job as a power bank and tops my 18650 just right at 4.20V. 80% efficiency in my testing and I get a full charge for my iPhone 6 from a 3100mAh panasonic. The flashlight head has a CREE XP-E to make about 160 lumens, bright enough for a tire change and it draws relatively little power. It is extremely well built and only takes unprotected cells.
I would also recommend the Miller ML-102, it works just as well as the C3, even a bit higher in efficiency (up to 83%). But without an battery indicator which could come handy if you want to use it as a charger for your 18650s. Only takes unprotected as well.
Let me know if you need more info about other models as well, I might have them.
Truthfully those Miller ML-102’s are not only chargers but a single cell portable power unit…and are dirt cheap
The ML-102s are nice, except I and other BLF member have ended up with some from recent purchases that freak out with a 2A load when cell voltage gets to ~3.5v (and well before the cell is even 50% discharged).
The TOMO V8-4 I tore down and reviewed has some shortcomings, but it has over discharge protection and each cell has its own shotkey diode for reverse polarity protection and to prevent cross-discharge among cells with different voltage levels along, and each also gets its own charging chip.
I think protection is pretty common on most DIY power banks, and at least a handful of the multicell powerbanks HJK has reviewed have provisions for managing each cell individually, like the TOMO, though the implementations may differ.
+1
I use the Miller for my emergency kits. I also got in an XTAR VC2 charger for review, which is entirely USB powered, though it doesn’t have a 5V USB port output like the Miller. For long road trips, I take along my I4 with the 12V cigarette lighter cord, and charge my li-ion cells on the road like a boss. But I’m never far from one of those Miller chargers and of course a slew of USB power packs. I routinely go a week on the road without plugging in.
Yeah, it seems they completely changed the way they step up to 5vdc, I have V6’s and they seem to hold solid…the V7’s seem to have some odd buck circuit and may be sagging when the current get’s high…bummer
Solar power bank chargers are nice, too. Units like the one below coupled with something like a Miller or VC2 let you move power around to where you need it, even taking it from the sun in emergencies. This one below is from GearBest, and pretty much everyone on earth sells them. Add one of those to the glove box and you gain a lot of capability.
Just wanted to pop back in and say thanks for the suggestions guys. I think I’m going to gift one of the C3 Charger/Torches to my parents (they want a rechargable flashlight) and pick up a few of the Miller ML102s
I got a nice Opus charger for Christmas so I no longer really need the charger, but I’d like something able to recharge a phone when out hiking or on the bike, or when I forget my 12v cigarette usb thing.
The C3 doesn’t deliver a lot of current and the emitter on mine is very purple. I’ve also seen reports of them going slightly too high on the charging voltage, but evidently not all do. The ML-102 is much better if you want a decent amount of current, though its battery shutoff does seem to be a bit conservative. Both can take protected cells with a bit of effort; in the case of the C3, the plug just sticks out a bit. Not a big problem. With the ML-102, it requires trimming the molded spacers and maybe some bending of the tabs.