Charging batteries---- Help!!!

[Visus]

I have a tp4056 charger and it says do not charge a 14500 battery because it charges @1000mah its actually 850mah in test.

http://www.ebay.com/itm/like/231070634174?lpid=82

I have 14500efest v2's and they can take up to 4c charge rate would it be ok to use this charger with efest IMR14500x2= 1400mah?

http://www.ebay.com/itm/2-EFEST-IMR-14500-Li-Mn-700maH-HIGH-DRAIN-Rechargeable-Battery-3-7V-BUTTON-TOP-/231118880171?pt=US_Rechargeable_Batteries&hash=item35cfc23dab

I hope not to have to change the resistor since the batts say 4c thats over 2amps charging but the charger maybe because IMR 14500 are so new the charger has old documentation?  Anyone know for sure I wont ruin the charger?

[Visus]

The test

http://lygte-info.dk/review/Review%20Charger%20TP4056%20UK.html

[Breaktru]

I've used that USB charger before. The charger comes set at 500mah. At least it did a year and a half ago. I would need to test it again. I have several in stock. I also measured 850 mah with the resistor set for 1A.
As a matter of fact the Li-Po blow out I had yesterday had that board in it and is now toast.

UPDATE: Just looked at he last batch I bought and it has the 122 resistor which is a 1.2K ohm meaning that it is set for 1A.

Here is a comparison of size:

[CraigHB]

An IMR 14500 can handle a 2C charging rate which would be 1200mA or 1.2 Amps.  Keep in mind there is a pretty big difference in wear between a 1C and a 2C rate, but it's so not so huge as to be impractical. 

Now the standard protected 14500s can only handle a 1C rate so you would be going over the limit with those.  If the board is testing out at 850mA then it's only marginally over the 1C limit there which is 700mA.  Probably be close enough not to be a problem.

None of these charging rate limits are hard limits, but rather they're recommended for acceptable wear levels.  If you go drastically over, then it can be a safety issue.  I probably wouldn't go above 2C for safety considerations even with an IMR cell.  I routinely charge the hobby LiPo that sits on my workbench for testing at 2C.  That one doesn't seem any worse for wear.

[Visus]

I've used that USB charger before. The charger comes set at 500mah. At least it did a year and a half ago. I would need to test it again. I have several in stock. I also measured 850 mah with the resistor set for 1A.
As a matter of fact the Li-Po blow out I had yesterday had that board in it and is now toast.

Here is a comparison of size:

UT oh not good news I hope all fingers and other parts are in tact..
I hope it wasnt the charger at fault
The 4056  looks huge next to the dna charger
I just checked my resistor, seems I am set at 500mah has a 221 resistor
says its a 1amp on purchase page and I would have to change the resistor
woot  great news but not so great I wanted the faster charge rate..  I already charge @420ma

[Visus]

An IMR 14500 can handle a 2C charging rate which would be 1200mA or 1.2 Amps.  Keep in mind there is a pretty big difference in wear between a 1C and a 2C rate, but it's so not so huge as to be impractical. 

Now the standard protected 14500s can only handle a 1C rate so you would be going over the limit with those.  If the board is testing out at 850mA then it's only marginally over the 1C limit there which is 700mA.  Probably be close enough not to be a problem.

None of these charging rate limits are hard limits, but rather they're recommended for acceptable wear levels.  If you go drastically over, then it can be a safety issue.  I probably wouldn't go above 2C for safety considerations even with an IMR cell.  I routinely charge the hobby LiPo that sits on my workbench for testing at 2C.  That one doesn't seem any worse for wear.

The charger gets really hot when charging and was why I was asking I have not benched it
Yeah the IMR cells I have, have a 4c charge rate so i knew they would be ok but the charger, will it blow?  I dont know..

[CraigHB]

The charger controller chip actually has to dissipate a good amount of heat.  It's the highest when the battery is lowest.  For example with a 5V USB input and a battery at 3.5V (pretty much the cell voltage when first put on the charger), the chip has to dissipate 1.5 Watts for a 1A rate which is a lot for a package that size.

I'm not familiar at all with the chip on that Chinese board and even if I could find the data sheet, it's probably in Chinese.  Likely it has "thermal limiting" which means the chip will drop the rate as required to keep die temperatures within tolerance.  In that case, you might find the rate lower than expected when the differential between USB input voltage and battery voltage is large.

Any chip with a 1A rate is going to require a thermal pad with a copper fill type of mounting for heat dissipation.  It does not look like that chip has a thermal pad so even if you change out the resistor for a 1A rate, it will likely hit thermal limiting and be unable to actually maintain a rate that high. 

The 1A charger boards you get from Adafruit use a Microchip MCP73833 charger controller which has the thermal pad mounted to a copper fill so those can actually maintain a 1A rate when set to use a 1A rate.  The same chip is also available without the thermal pad and those can't to better than 500mA.

In any case, it's not unusual for the chip to get pretty hot.  It should have thermal limiting and automatically protect itself from overheating.

[CraigHB]

Oh, BTW, those eFest 14500s test out to 600mAh even though they say 700mAh on the ratings.  The numbers I used before for the 2C rate on a 14500 are for an AW IMR 14500 which has an accurate rating of 600mAh.

http://lygte-info.dk/review/batteries2012/Efest%20IMR14500%20V2%20700mAh%20%28Red%29%20UK.html

It's a bad sign for battery makers when they exaggerate the ratings, but I've seen worse so the eFest batteries aren't horrible batteries by any means.

[Breaktru]

I'm not familiar at all with the chip on that Chinese board and even if I could find the data sheet, it's probably in Chinese.  Likely it has "thermal limiting" which means the chip will drop the rate as required to keep die temperatures within tolerance.  In that case, you might find the rate lower than expected when the differential between USB input voltage and battery voltage is large.

I have the Chinese TP4056 charger datasheet posted HERE

[CraigHB]

Well, at least someone translated it, though it's pretty sketchy and there's some Chenglish in there.

It has a thermal pad so that's good, you can see that in the little photo provided in the document.  Though it depends on if it's actually soldered to a a copper fill on that cheapo board.  If so, it can maintain a 1A rate, if not it can't. 

This is pretty dismal, "Preset 4.2V Charge Voltage with 1.5% Accuracy".  1.5% is a lot of error for a charger controller.  The Microchip controllers are half that.

Leakage is pretty high, it's in the microamps.  The Microchip controllers are in the nanoamps.

It has thermal limiting, it would have to really, "Thermal feedback regulates the charge current to limit the die temperature during high power operation or high ambient temperature".

In any case, it looks like it should be able to do the job alright.  Not a quality charger board by any means, but for $2 you can't expect too much.

[Breaktru]

I just checked my resistor, seems I am set at 500mah has a 221 resistor

Could it be that you are looking at the resistor upside down? That's what I did at first and then realized it was 122 not 221.
221 is 220 ohms and 122 is 1.2K ohms

For 500ma you would need something like a 2.4k (242) or 2.5k (252) resistor.

[Visus]

LOL holy cow I am set to 1 amp you are correct,  upside down read LOL..  Thatnks for data sheet..
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@ Craig I hope that it is soldered;  the guy does says use a heatsink and it helps amazingly.  I have an old pc heatsink, I was gonna use some kapton isolation and run it like that.   I have a wide roll of kapton,  will it insulate the heatsink too much IDK..
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I am vaping a 1.5Ohm micro coil, 2.5mm airhole, a dripper,  and whoa room fogger.    The batts with this ohm coil when they get to 6.7v the rattle snake sound starts on an 08100.  Really cool,  I know now when to charge without idiot notifier..  If I get this charger running smooth only 1.5hr to charge them as opposed to 4.7hr now..

[CraigHB]

Oh, I finally noticed that link to the review on that board, lots of thermal data there so no problem on the thermal characteristics, they're fine.  The failure to achieve a 1A rate is probably due to controller error for the the rate adjustment.  You could probably extend the value of that resistor to achieve the 1A rate.  You can see the high controller error in his data and he comments on the leakage.  It's high, though he doesn't make an issue of it.

[Breaktru]

I had bought 10 for about a buck a piece w/ free shipping and used most of them which worked well.
Yesterday I hooked one up and the board was dead. I checked for 5v between IN+ and IN- and had nothing. Checked for continuity from Pin 1 to IN- and Pin 5 to IN+. Both showed open. So I hit it w/ some solder and it's working now.

[Visus]

WOOT


They are quite huge but the price is right and for 10,  wow, that is giving them away..
 

2014 HNY!

[Breaktru]

Here are 5pc for $4.90 plus $1 US shipping Mini USB 1A With shipping thats $1.18 a piece.
About the size, it has it's place in certain mod boxes. Where size is a factor I use the evolv charger.

The Sparkfun charges are nice too. You can cut the board down.
MCP73831T

[Visus]

Wow thanks Break that cut makes that charger smaller than the 4056 and everyone raves about it in reviews woot..

I do  have a 500mah model its 2.1k on meter unfortunately..  80 more mah than the 420 I charge at now will be a tad quicker.   
I so wanted the 850mah without soldering..