Another charger switch desired?

So I recently got a VP2. Initially I was kind of intimidated by all the settings. The only other Li-ion charger I had was a Fenix. It charged my 18650s. You put them in until the light changed. Pretty simple. This VP2 has switches to select voltage and current. It seemed "complicated".

But I got over it. Now I understand why and when to use which settings for which batteries and I'm loving the flexibility.

Then I get to reading on BU that you can increase battery life by using a shall charge cycles and not leaving the battery fully charged. And it's not a small increase. We're talking 300-500 cycles increasing to over 4,000! That's a lot!

Now I find myself wishing the VP2 had one MORE switch. Call it a max run vs max life vs storage switch. On max run it fully charges the battery. On max life it charges to, say, ~90% (4.1v vs 4.2v on a typical ICR 18650) On storage it would charge (or discharge) the battery to ~60% (say 3.8v)

For my use, I'd just leave it set on max life 90% of the time. I'd only top them off if I was taking the light out of town for a while. I don't think I'd use the storage setting much but I only have a few extra batteries at this point.

Now, I know I can do all this "manually" with the VP2. I can pull batteries off before they are "done", and I've actually started to do this, but this seems like a great idea.

I also know batteries are "cheap" and just buying a new set every year or two isn't a hardship on most people, but still, extending a battery's life from a couple years to maybe 10 seems like a good thing, financially, environmentally and just more convenient. At 10 years, one set of batteries will outlast the "usable" life of the flashlight (even if it works like it did day 1 the technology has advanced)

Is this something you folks would like to see on higher end chargers? Or a complete waste of time and effort. Interested to hear what everyone thinks about this (or does it already exist somewhere?)

Ken

Hi Ken,i guess its down to what people would pay,majority would probably say $40-$50 is enough on a charger,with extra options added then so would the cost.
Of course its just examples but say $100 for all this convenience,how many would sell,how many would see the benefit and think its cost effective long term(charger could pack up after 3yrs) or newer advanced come out anyway for less as time goes on.

Personally i am happy with charging the cells as per norm,i try and run them down to around 3.9v and top off. So if i used for 10 minutes i wont slap them back on charge,but rather 20 mins use(varies depending on light and just using guesstimates) and charge back up. I like to be good to go and it makes it a little more user friendly.Watching the charger for 4.1v obv takes your time at 1st till you can roughly work out,but then you have to clock watch which takes time and some of the enjoyment out of it for me(just my personal opinion here thats all:thumbsup

I have some cells that must be 5yrs old and still good,technology improves so how many cells i have now would i want in 5yrs time.There maybe 4000mah IMR at 40A for example..............or more.
If you worked out the time say from 3.8v to 4.1v at 1A you could maybe set a plug timer for the time to switch off(just a thought here).

The 300-500 cycles is full cycles,so by topping off from 3.9v to 4.2v it is several top offs to =1 cycle which pretty much sums up my style of use.Now and then the odd cell will be down to 3.7v ,but rarely this happens. I have that many cells and lights it would be a full time job for me to do it manually,but to set the voltage cut off would be a good idea if the cost would not be that much higher.

Digital readout,set termination voltage(would not need 3.6v(4.2)/3.8v(4.35) settings) as could manually input 4.1 and 4.35 for example. That i would like but i think manufacturers like to keep things safer/user friendly for the general public as well as remaining competitive cost wise.

Maybe hobby chargers allow this(dont know as dont own one) but if so,maybe that would make an alternative option good to go ........

So in summary(from my waffle) i would like an option to set termination V ,but not enough to pay a high premium over the chargers available right now.

What i would like is something like a vp4 or vp6 with extra bays more than anything.

Regards ven:thumbsup:

As long as I use quality cell, I'm not too concerned about its life. I charge to max capacity because I never know when I'll need the runtime.
Even like this, it will take a while for the cell to go "bad".
Pulling it off the charger manually, I would only use it in single cell lights. For multi-cell, I like them as equal as possible and from the same batch. I don't mix and match not just my li-ions but also my ni-mh/Eneloops.
They are marked, even color coded by batch and how many per set. My singles, I use different colored cells. I don't mind different brands as well as long as I use quality ones. Easy for me since I only have a few cells anyway and the most cell I personally like in a light is 2 li-ions. I really don't have use for lights that are more than that.

Perhaps the others with multi-cell lights can give their opinions/techniques/habits etc.

With my multi cell lights i use a set "set" of cells for each light,so i dont mix any up(yep works out expensive) .Once i have used it(dependent again) i top off all 3 or 4 cells depending on light(dont have any more than 4 cell lights) . Some i have protected,others from vinh IMR too.

I have a bomb draw........spare cells kept here


Others i have are kept down stairs for VV mods etc
Other cells in my lights like vtc5


There are around 6 lights that have 4 cells in and 2 with 3 cells in(tk51/tn35vn for example),rest are single cell(or nimh AA/AAA etc)


There is another 10 or so lights on top of these too,so not easy for me to charge manually to 4.1v regarding time,ones that have not been used i make sure do,then top off cells again.So none are stored too long and the ones i can i lock out too........

So good habit or bad i top off cells be it single or multi,multi together at set times or after set usage times.

:thumbsup:

kbuzbee said:

Then I get to reading on BU that you can increase battery life by using a shall charge cycles and not leaving the battery fully charged. And it's not a small increase. We're talking 300-500 cycles increasing to over 4,000! That's a lot!
<SNIP>

Ken

Click to expand...

Hi Ken,
I suspect that you misinterpreted what you read.

One FULL charge CYCLE equals Multiple small charges. For example twenty 5% charges equals ONE charge CYCLE.

kbuzbee said:

Now I find myself wishing the VP2 had one MORE switch. Call it a max run vs max life vs storage switch. On max run it fully charges the battery. On max life it charges to, say, ~90% (4.1v vs 4.2v on a typical ICR 18650) On storage it would charge (or discharge) the battery to ~60% (say 3.8v)

For my use, I'd just leave it set on max life 90% of the time. I'd only top them off if I was taking the light out of town for a while. I don't think I'd use the storage setting much but I only have a few extra batteries at this point.

Ken

Click to expand...

Ken,
It sounds like a good idea to me.

For the most part, I fully charge the batteries I keep in my lights.
The others I store between 3.9 and 4.0 volts in the refrigerator, (honestly I am not too particular) some may be at full charge before I remember to pull them off the charger.
Age of the battery, number of FULL charge cycles, average % of charge, and temperature are the five variables that determine battery life (other than initial quality).

I can't change the age.
I'll NEVER use all the charge cycles
I want USEABLE batteries the moment the need arises so I keep them above 3.9 volts at all times.
It's easy to control the temperature by putting them in the refrigerator.

I've grown accustomed to NiCads lasting about 1.5 - 2 years before there is an appreciable drop in performance. So 5 years or more out of my 18650s, that's great!

Yes ,so many factors,used on turbo on high demanding lights,used in warm climates will all shorten its life more than a cell used moderately in cooler conditions/climates. Be it a year,maybe 2 ............i dont know.

Chris salvaged some laptop cells of 12yrs young,and hold charge(sony iirc) which is pretty astonishing..............

I am pretty much the same poppy,i want to be good to go and usually my cells are around 4.17 to 4.19v. I dont put mine in the fridge though,the thoughts of a 4.2v sandwich and the explanation of god knows how many cells would be the demise of ven :laughing: The cells i store are around 3.7/3.8v in the draw,temperature is never high ,admittedly not as good as a fridge.
:thumbsup:

ven said:

I am pretty much the same poppy,i want to be good to go and usually my cells are around 4.17 to 4.19v. I dont put mine in the fridge though,the thoughts of a 4.2v sandwich and the explanation of god knows how many cells would be the demise of ven :laughing: The cells i store are around 3.7/3.8v in the draw,temperature is never high ,admittedly not as good as a fridge.
:thumbsup:

Click to expand...

Hmmm... with a little Mayo... :thumbsup:

They're in the spare fridge. And the NiMH batteries are fully charged in a drawer in my desk. They get cycled into blood pressure cuff, pencil sharpener, Wii remotes, (not so much flashlights). The 18650 lights get more use around here.

BloodLust said:

Pulling it off the charger manually, I would only use it in single cell lights. For multi-cell, I like them as equal as possible and from the same batch. I don't mix and match not just my li-ions but also my ni-mh/Eneloops.

Click to expand...

This was exactly the scenario that got me thinking about this. Like you, I don't really care in single cell lights. I only have one light that takes more than one (3x 18650s) - that's not counting a 18650 light as 2x CR123s. The 3x 18650 light I make sure to top off all three cells before using them.

ven said:

Hi Ken,i guess its down to what people would pay,majority would probably say $40-$50 is enough on a charger,with extra options added then so would the cost.... So in summary(from my waffle) i would like an option to set termination V ,but not enough to pay a high premium over the chargers available right now.

Click to expand...

Exactly, cost is a factor, but first I just wanted to see if anyone even thought it was a useful idea. I (based on, well, nothing, actually ) would expect this to add around $10, so a VP2v2 would run ~$60, but I could be WAY off.

ven said:

What i would like is something like a vp4 or vp6 with extra bays more than anything.

Click to expand...

You and me, both, brother!

Poppy said:

Hi Ken,
I suspect that you misinterpreted what you read.

One FULL charge CYCLE equals Multiple small charges. For example twenty 5% charges equals ONE charge CYCLE.

Click to expand...

I actually did read that. And that would impact just how beneficial this might be. Still, the numbers you read for cell life, in general seem to run around 2 years. I have 18650s that are still going strong after 4 so I'm guessing this isn't really needed. Still seems like a cool idea if it could be done cost effectively.

i do like your idea of storing them in the fridge. I can only imagine the comments that would get me

Ken

ven said:

If you worked out the time say from 3.8v to 4.1v at 1A you could maybe set a plug timer for the time to switch off(just a thought here).

Click to expand...

Yeah, I recall someone here did that with their iPad. Used one of those on-off cycling timers to keep their iPad ~70%. Can't recall who but it seemed like a great idea. But even though our original iPad 1s no longer went 10 hours on a charge, they still went 6, which was usually enough. They didn't "die" or anything. We replaced them with Mini 2s for general technology increase, not strictly because of the battery life.

Ken

Yuv could probably mod your charger to do it.
I did.
I adjusted my charger to charge Some batteries to a slightly less voltage so that they would not blow the bulb in One of my sensitive Incan lights.

I then added a switch to switch between this mode and full voltage.

Somewhere in you charger is a resistor that calibrates the cutoff voltage, it you can find it, you can then change it's value to set a custom cut off voltage.

It you charger has a switch that set different voltages that would lead you right to it.

Xtar VP2 you said ?

It has a lifepo4 setting ? That will cutoff at about 3.6something volts which is in and around the storage voltage of a li-ion.
You could just try charging your batteries on the lifepo4 setting and see what happens.

They use the same algorithm I believe, the only difference is the cut off voltage.
At least I know that's how my charger works.
The only difference between lifepo4 mode and Li-ion mode was the resistor I was talking about telling the charger when to quit.

I'm pretty sure you may have your solution right there.

Conte said:

I'm pretty sure you may have your solution right there.

Click to expand...

Half of it, anyway. That would work for the storage setting but it would still need the max life setting. OTOH, running the newer 3.8v batteries on the 4.2 setting may well be the answer. Nicely done!

Are there 3.8v 16340s & 18350s yet? I haven't run across them.

Ken

Not that I'm aware of. To be honest, those new higher voltage batteries are new to me. Didn't know about them a month ago, and I can't say that I've found a sale listing for one yet.

I almost want to offer you send the charger to me for calibration. If you never plan to use the higher voltage batteries, I'd use that position on the switch for your special requirement.

Or maybe you'd consider buying another charger specifically for this task. It'd probably be easy to add a resistor to dock all the positions down to the long life setting. In my charger 1k of resistance dropped the cutoff 0.1v.

How confident are you to open that charger up to take some pictures ? I could tell you what to look for, then we at least know if it can be done and is worth the trouble.

That is a most generous offer, brother. It looks easy enough to pop open, but I think we've already found the solution. I'll be VERY surprised if 3.8v doesn't work it's way into the general scheme of things over the next year or two making this whole question moot. (or, at the least, self manageable )

Ken

One thing I'll point out . . . do you have a multi meter ?
Are you sure the charger is even giving you the voltages it claims ?

Notice that the specs of the VP2 are like 4.2v +/-0.5
It's within tolerance, but it's possible that it's charging your batteries to 4.15 or 4.25v.

In my case, my charge erred in favour of +0.5v, charging my batteries to 4.25v. For the longest time I was none the wiser until I bought some sensitive bulbs that would even tho' they were designed for the batteries I was using. Sure enough, that's when I learned about the overcharge. Which is how I learned to mod my charger to bring it down to 4.15v. I added a switch to keep the 4.25v setting as I had been using it for years and the batteries have not complained.

Just something to think about.

Conte said:

One thing I'll point out . . . do you have a multi meter ?
Are you sure the charger is even giving you the voltages it claims ?

Click to expand...

I do and it's actually pretty close. I read 4.19v when the VP2 is telling me 4.2v. Good thought though. Thanks!

Ken

I've noticed that I can get a .01v-.02v lower reading immediately after taking my cells off the VP2, according to my Rat Shack 22-805 DMM.

I think that this is in part due to the Xtars traditionally 'undercharging' and the fact that the battery starts 'settling' once removed. I'll have left cells in the charger for 20-30 minutes and notice that the voltage display drops, as well.

Chris

Nice thread. I am just starting and new to the use and care of Li-Ion 18650s mah 2600 and Fenix's 3400 with Fenix 2 cell charger. Read some scary bogus cheap high mah battery stories, so I have got the best well known ones for my 2 flashlights. Plan to not use the CR123s except in power failures (in hot humid Louisiana).

Just purchased Army Tec Barracuda (2) cells and Fenix PD 35 (1).

Any basic care and use battery suggestions would be greatly appreciated. Thanks.

Charles