Pila charger quandry

[oplholik]

Ok, so I'm wanting to get another charger as I'm getting a lot of batts to keep charged. I already have a wf-188 and a Pila. The Pila I have only has one working bay out of the two. One bay shows about 4.12 on my mm, and the other bay reads about 4.03. It's been this way since shortly after I got it. I did send it back to where I bought it from(not Pila), to be checked out, and it was returned as working as it should. So I decided that I was not going to pay shipping again to send it to Pila, as they require only Pila battery use for the warranty. I don't know how that works, but I've never owned a Pila batt.
So my quandry is, should I take a chance and get another Pila? I do want a good charger, and I'm thinking that I just got 1 out of I don't know how many, that happened to have a problem.
Any thoughts on this from you Pila owners? Thanks.

 

[WillyB]

. One bay shows about 4.12 on my mm, and the other bay reads about 4.03.

Are you talking about the charger volts? Have you actually checked the cells when they come off the charger?

 

[oplholik]

I checked the batts when I take them off. One bays charges just fine, the other bay won't fully charge the batt, and on that one bay the lights wont work correctly.

 

[WillyB]

Well about the only thing you can do is to try and make sure it is fact making firm contact at both ends. Look at it hard, you could also try a thin aluminum foil shim to tighten things up a bit.

You didn't say if the spacers are involved.

Too bad though.

 

[oplholik]

This morning I put on two batts from a set. Batt in left bay charged to 4.15v in a short time, the batt in the right bay I left on for an additional 45 minutes as the light was still red, checked it and was only charged to 3.78v, which is probably what it started at.
This is typical of how all my batts do on this charger. Definately has been a bum charger, thus my hesitancey in getting another one.

 

[WillyB]

Batt in left bay charged to 4.15v in a short time,

That also doesn't sound good, especially if that's right off the charger. One of the big deals about Pila is how well they consistently nail a properly saturated 4.2V.

Who did you buy it from? Sure seems like you got a bad one.

 

[jpracing]

You got the 1 in a hundred thousand that doesn't work like a swiss watch.
I have a few of them and every one charges bang on to 4.2v.
Get another one.....or three.

 

[oplholik]

That's kinda been what I have been thinking.

You got the 1 in a hundred thousand that doesn't work like a swiss watch.

 

[jpracing]

If you do decide to get another one, or three , buy it new from a Pila distributor.
My pila chargers have been great at keeping my batts in top condition.
I haven't seen any of them come off the charger at below 4.2v yet.

That's kinda been what I have been thinking.

 

[Dan Patrick]

I use mine everyday and it works like a champ. It charges batteries my wife's cheapo Trustfire by her bed says are charged but are still dead and gives them new life. Though I don't know if that's a good thing or not?

 

[oplholik]

Just ordered another from RTDVapor(crossing fingers). The first one I had ordered from a different vendor, not that it matters, but get my batts from RTD, so went there for the charger.

 

[jpracing]

Good luck and let us know how it goes.

Just ordered another from RTDVapor(crossing fingers). The first one I had ordered from a different vendor, not that it matters, but get my batts from RTD, so went there for the charger.

 

[rolygate]

Just for the sake of full info, some people take their Li-Mn's off charge at 4.1v or sometimes 4.0v. The reason is that the cell will take more recharges if you do that - the service life is increased. The downside is that if using a single batt mod then you lose the first 0.2v of the highest 'hit', and the batt will need a recharge sooner.

But if you don't really notice that (and certainly if it is a 2-cell mod) then it would be a way to save money, as those batts aren't cheap.

Doubt if many people do this, but it is not 'wrong' to take a cell off charge at 4.1 or even 4.0, if it suits you.

It's probably more interesting to discuss what voltage to drop it down to as the minimum. The one thing I'd really like, that is missing on basic mods, is a minimum voltage warning LED. Then people would argue what to set it at...

 

[Dan Patrick]

Yeah, I have a Boge Lea and it has a button that changes color with charge. Green, Yellow, Red. I always charge it at Yellow. And of course the Provari blinks at you once the battery gets to a certain voltage. I always put them on the charger the second they blink. But i think my wife's og buzz is just taking the charge down to nothing, and they get so low that her charger can't even recognize the voltage they they are at.

 

[oplholik]

When I first got the Pila, I noticed on the protected batts, that they would only charge to about 4.17-4.18v, and I questioned the vendor about this, and was told that the Pila is designed to charge to that voltage, and that the cells would last longer. The IMR's will charge to 4.2v however I found, which I think has to do with lower resistance.

Just for the sake of full info, some people take their Li-Mn's off charge at 4.1v or sometimes 4.0v. The reason is that the cell will take more recharges if you do that - the service life is increased. The downside is that if using a single batt mod then you lose the first 0.2v of the highest 'hit', and the batt will need a recharge sooner.

But if you don't really notice that (and certainly if it is a 2-cell mod) then it would be a way to save money, as those batts aren't cheap.

Doubt if many people do this, but it is not 'wrong' to take a cell off charge at 4.1 or even 4.0, if it suits you.

It's probably more interesting to discuss what voltage to drop it down to as the minimum. The one thing I'd really like, that is missing on basic mods, is a minimum voltage warning LED. Then people would argue what to set it at...

 

[WillyB]

Just for the sake of full info, some people take their Li-Mn's off charge at 4.1v or sometimes 4.0v. The reason is that the cell will take more recharges if you do that - the service life is increased. The downside is that if using a single batt mod then you lose the first 0.2v of the highest 'hit', and the batt will need a recharge sooner.

Doubt if many people do this, but it is not 'wrong' to take a cell off charge at 4.1 or even 4.0, if it suits you.

It's probably more interesting to discuss what voltage to drop it down to as the minimum. The one thing I'd really like, that is missing on basic mods, is a minimum voltage warning LED. Then people would argue what to set it at...

No offense but that doesn't seem very practical, unless of course you have no problem charging to about 75-80% of your cells capacity. A cell yanked from the charger at 4.1V after a short rest may well end up at 3.8V... unacceptable. At BatteryU they use the term saturation.

Note that a Li-ion battery that received a fully saturated charge will keep the higher voltage longer than one that was fast-charged and terminated at the voltage threshold without a saturation charge.

Cheap chargers or yanking will simply cut-off at a voltage limit, but that is only half the battle.

Basically a proper CC/CV cycle will charge at the current limit until it reaches the voltage limit, but it does not stop at this point. The charger is held at the voltage limit, but continues with current.

Here's a blurb from Power Stream:

The lithium ion battery is easy to charge. Charging safely is more difficult. The basic algorithm is to charge at constant current (0.2 C to 0.7 C depending on manufacturer) until the battery reaches 4.2 Vpc (volts per cell), and hold the voltage at 4.2 volts until the charge current has dropped to 10% of the initial charge rate. The termination condition is the drop in charge current to 10%. The top charging voltage and the termination current varies slightly with the manufacturer.

The moral of the story is that you check a cell charged in a chintzy charger and you see 4.2V, you charge the same cell with a good charger that follows the correct CC/CV algorithm and it too shows 4.2V, but that cell may in fact have 10-20% more capacity.

 

[rolygate]

That is all true.

However I'm talking about a different thing here, the data available indicates that a Li-Mn cell has a longer service life if not fully charged. This is the direct opposite of several other types of cells.

For example:
an Li-Mn cell taken off charge at 4.1v can be found to be 4.1v after several days

repeated recharging of an Li-Mn cell to any level has no effect on its capacity, but it has a considerable effect on its service life if those recharges are to less than 100% capacity - service life can be more than doubled

an Li-Mn cell charged to 4.0v has >500 potential recharges
an Li-Mn cell charged to 4.1v has >300 potential recharges
an Li-Mn cell charged to 4.2v has >200 potential recharges


From memory this was the data I found. In my case, a charge to 4.1v or even 4.0v is preferable since I don't vape the cell down to the bottom as there is no need. For my usage profile, a battery that lasts twice as long looks to be a good deal. This may not apply to others but it seems worth mentioning, to me.

I spent many years working with battery stored power systems for remote living. This included half a dozen different types of cells, different generators such as wind turbines, diesel engines with vastly different types of alternators and alternator controllers, solar panels, and hydraulic turbines; the management panels for the systems including monitoring, metering and regulators of different sorts; and the different types of inverters used for differing purposes. It's likely that I know more about this area than the person who writes Battery University, since most fields are too large to specialize in everything. I did find some inaccuracies in their material on my specialist area, some years back, but expect that to have been corrected as that is what technical authors do - they edit over time.

As far as Li-Mn cells go, I can only re-cycle data found elsewhere and trust to its accuracy. Li-Mn cells are not lead acid or Nicads, they are very different. If I read information from a manufacturer or vendor or expert user who has the data from thousands of tests of Li-Mn cells, I just have to assume they know what they're talking about. I certainly don't, in that area.

Who knows

 

[WillyB]

I understand your point, if you are only charging to 80% each cycle you'll get more 80% cycles. But What I'm saying is to take an already mAh challenged 1600mAh cell and make it a 1200mAh cell is not what I would do.

When you said:

repeated recharging of an Li-Mn cell to any level has no effect on its capacity, but it has a considerable effect on its service life if those recharges are to less

Are you inferring that a LiMn does not need the standard CC/CV charging algorithm? I think it applies.

You said.

an Li-Mn cell taken off charge at 4.1v

Here's a typical charging profile.

In this case we see that we get to 4.2V rather quickly, about 1.6 hours but at that time our capacity is only at about 80%. To get to full capacity we need at least double that time. Sanyo on one of their cells has the termination listed as when the current drops to 50mA.

As far as charge cycles there is no free lunch. Sanyo provides some accurate details (they have to with the customers they deal will). For their UR18650F they list 500 charge cycles, but looking at their graph at 100 cycles capacity has dropped by ~6%.

Oh well, food for thought...

 

[oplholik]

I'm glad you guys understand all this.
I got the new Pila today, and saved some batts for it to see how it does. Now I got 1 1/2 Pilas. If this one is good, I'll feel more comfortable about getting another.