Any charger for Li-ion that stops below 4.20V?

[Cemoi]

According to the excellent Pila IBC charger compendium, if Li-ion are charged up to 4.15V they have 95% of they total capacity left, which is fine for me. Only 5% less capacity, a good trade off IMHO for an optimal long-term battery health.
Is there any way to have the Pila IBC stop below 4.20V, or any other charger that behaves so?

 

[KiwiMark]

Is there any way to have the Pila IBC stop below 4.20V, or any other charger that behaves so?

I have a charger that can charge to 4.2V or to 4.1V, it is a good price but must be connected to a 12V power source and you need a battery holder or magnets to connect it to the battery you want to charge. I use it powered by a PC PSU (short green & black wires from m/board connector and it turns on fine).

This is it:
http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=7028

4.1V would be close to 90% capacity and will allow significantly more charge cycles before the battery 'wears out'.

 

[tino_ale]

Very interesting topic.

I would really like to see a serious "study" about end of charge voltage (4.2, 4.15; 4.1V etc) versus loss of capacity.

I've been waiting for a long time for common electronics goods (like laptop, music players or whatever uses li-ion/li-poly cells) to have a USER setting for max capacity or max battery life.

Now I try to unplug the charging lead when the charge is around 90% (as long as I don't need the full capacity, which is generally easy to plan).

 

[Dynabel]

My Pila IBC stops at 4.17V, charging 18650 and 14500 cells.

 

[CaseyS]

My Ultrafire WF-139 also charges to 4.17V.

 

[mr.snakeman]

My Ultrafire WF-139 also charges to 4.17V.

As does mine :thumbsup:

 

[EngrPaul]

Just a word of advice. Consider the +/- on your meter. It may be a wider range than what you are trying to decipher.

 

[CaseyS]

Just a word of advice. Consider the +/- on your meter. It may be a wider range than what you are trying to decipher.

I'm using a Fluke 115.

 

[556man]

My Ultrafire WF-139 also charges to 4.17V.

Same here

556man

 

[txg]

I've been waiting for a long time for common electronics goods (like laptop, music players or whatever uses li-ion/li-poly cells) to have a USER setting for max capacity or max battery life.

as for laptops, don't wait any longer

with ibm (now lenovo) thinkpads this is possible since ca. 2004. in their battery manager, you can enter the level in per cent where charging should begin (e.g. 85%) and where it should end (e.g 90%).

 

[SunFire900]

My Ultrafire WF-139 also charges to 4.17V.

I'm glad you guys mentioned this. My WF-139 also charges to 4.16-4.17. I think that the reason there has been some negative comments about the WF chargers is because there are different versions made of them. Some good....some not so good. Some dark, some light and some white.

AW sells these chargers exclusively along with some of the best lithium rechargeable cells available. I don't think he would sell a charger that he thought would ruin his cells. That is why I bought my WF-139 as my first li-ion charger.

 

[flatline]

My Pila seems to cut off somewhere around 4.17.

If I periodically roll the cell in the charger, the light will flip to green starting at about 4.11, so if I want to pull them off early, that's what I do.

If I really want the cell charged up to 4.2, then I hit the reset button when it finishes the first time. That usually does it.

--flatine

 

[SunFire900]

I am not one to try to get 3 years of use out of a cheap (low cost) cell. I like a 95-100% full charge each and every time I charge a cell. I don't want to have to roll, pull and reinsert or reset in order to get the charge I want.

Whenever you or I put two cells in a two-bay charger, we should get, on completion, two fully (or close) charged cells with matching voltages. Not one cell having 4.20v and the other with 4.12 or 4.16v. When this happens, you have to perform one of the above actions to get the voltage up to match the other cell. Good luck with that. It is a nuisance, a bother and a waste of time.

I have only had only one charger so far that would charge to 4.20v. per cell, 100% full charge each time. After about 10 charge cycles it burned out Just my luck.

The other chargers I have either overcharge or are inconsistant (uneven termination voltages).

It is important to always check the cells' voltage coming off any charger to be sure the cells are closely matched.:twothumbs Matching cells' capacities is another story altogether.......

 

[KiwiMark]

I have only had only one charger so far that would charge to 4.20v. per cell, 100% full charge each time. After about 10 charge cycles it burned out Just my luck.

The other chargers I have either overcharge or are inconsistant (uneven termination voltages).

It is important to always check the cells' voltage coming off any charger to be sure the cells are closely matched.:twothumbs Matching cells' capacities is another story altogether.......

I have 2 x WF-139 and they were bought from 2 different suppliers at 2 different times - but when I charge 4 x 18650 cells on those chargers they all seem to be charged exactly the same.

For matching cell capacities I think that is one thing were you need to get good quality cells. The cheaper cells are often not made 100% consistently with greater tolerances and bigger variations. Not necessarily just when the cells are new, often over time different cells lose different amounts of capacity and they become more mismatched. Of course they don't need to be exact to the nearest mAh - but they should be close enough so that when one is out of juice the other is out of juice. You don't want a quarter charged cell pushing power through a completely drained cell. 2600mAh and 2585mAh would be OK, but 2400mAh & 1900mAh would be REALLY bad running together.

You should ALWAYS use 2 cells of the same size/brand/age and use them together as a pair. Hopefully they will start out almost the same as each other and slowly degrade the same as each other. It is handy to have single cell devices that can happily run on the cells that have fallen badly out of sync with each other.

 

[SunFire900]

I have 2 x WF-139 and they were bought from 2 different suppliers at 2 different times - but when I charge 4 x 18650 cells on those chargers they all seem to be charged exactly the same.

For matching cell capacities I think that is one thing were you need to get good quality cells. The cheaper cells are often not made 100% consistently with greater tolerances and bigger variations. Not necessarily just when the cells are new, often over time different cells lose different amounts of capacity and they become more mismatched. Of course they don't need to be exact to the nearest mAh - but they should be close enough so that when one is out of juice the other is out of juice. You don't want a quarter charged cell pushing power through a completely drained cell. 2600mAh and 2585mAh would be OK, but 2400mAh & 1900mAh would be REALLY bad running together.

You should ALWAYS use 2 cells of the same size/brand/age and use them together as a pair. Hopefully they will start out almost the same as each other and slowly degrade the same as each other. It is handy to have single cell devices that can happily run on the cells that have fallen badly out of sync with each other.

I fully agree. All my cells are marked/dated as soon as I receive them and they remain as a pair for the duration. If one is bad, it's recycled and the good one is only used in a single cell light. For this reason, I am not a big fan of 3-cell lights.

My 139 almost always ends with one cell 4.14 and the second 4.17v.

 

[PCC]

I was just about to post a question about this.

My brother gave me his old Multiplex LN-5014 hobby charger. I downloaded the instruction sheet and it says that it charges Li-Ion batteries to 4.1V while it charges Li-Po batteries to 4.2V. The battery type is user selectable so I can use the Li-Po setting for Li-Ion cells and was wondering if this would cause me any headaches down the road. After reading this thread I'll leave it in the Li-Ion setting.

 

[KiwiMark]

I was just about to post a question about this.

My brother gave me his old Multiplex LN-5014 hobby charger. I downloaded the instruction sheet and it says that it charges Li-Ion batteries to 4.1V while it charges Li-Po batteries to 4.2V. The battery type is user selectable so I can use the Li-Po setting for Li-Ion cells and was wondering if this would cause me any headaches down the road. After reading this thread I'll leave it in the Li-Ion setting.

Either setting will work quite well
- charging to 4.2V gives the most charge you can get without pushing the cell to an early death.
- Charging to 4.1V gives a good charge (somewhere around 85-90%) while being quite gentle on the cell.

If you charge batteries daily and want to see 2 or 3 years of very regular use then the 4.1V setting might be the best - you will get many more cycles at that setting. For batteries charged every month of 2 it isn't likely to matter much - the Li-ions fail with age and no amount of babying can stop that.

 

[PCC]

Thanks for the info! I guess I'll be using the Li-Po setting from now on since I will be charging these occasionally. Also, these cells were essentially free (I work IT and we had a brand new Dell battery sit on the shelf for too long and the internal circuitry registered the voltage of the cells as too low so it "failed" it at around 3V per cell. I then took it apart and scavenged the unprotected cells from it. I'm using these cells with a drop-in that has a built-in low-voltage cutoff at 2.8V). I'll google the shelf life thing.

 

[flatline]

Thanks for the info! I guess I'll be using the Li-Po setting from now on since I will be charging these occasionally. Also, these cells were essentially free (I work IT and we had a brand new Dell battery sit on the shelf for too long and the internal circuitry registered the voltage of the cells as too low so it "failed" it at around 3V per cell. I then took it apart and scavenged the unprotected cells from it. I'm using these cells with a drop-in that has a built-in low-voltage cutoff at 2.8V). I'll google the shelf life thing.

I bought an MG L-mini II for exactly the same reason. Got 6 perfectly good cells out of my wife's laptop when she replaced the old battery pack and we dump a laptop or two every couple of months at work. I should have an unlimited supply of salvageable unprotected 18650 cells to use. Too good an opportunity to pass up.

If the MG PLI ever shows up with a warm emitter, I'll get one of those, too.

--flatline

 

[Cemoi]

My WF-139 also charges to 4.16-4.17

Your and CaseyS' reply make me think that the WF-139 is a good choice to slightly undercharge the cells, especially considering its low price ($12.30 including shipment: 1/4 the price of the Pila).

I think that the reason there has been some negative comments about the WF chargers is because there are different versions made of them. Some good....some not so good.

According to some of the reviews on the DX page the recent versions of this charger have a higher cut-off voltage (4.25V), harder on the cells.
Some reviewers suspect that there may be some counterfeit WF-139.

AW sells these chargers

I'd be happy to pay the few extra dollars (WRT DX price) as a guarantee against counterfeit or overcharging WF-139. Since AW seems to be a very reputable dealer on CPF, I'm inclined to think he has a more reliable source for Ultrafire chargers than DX and/or checks the chargers before shipping them. Am I correct?