Hi,

I just receive my V8 and put a VTC4 to charge in it.
The led goes green at 4.16V.
Can it be solved? Or I just received a buged one?

How old is your VTC4?

Not so old, I think around 6 months and take full charge with my acccell 6.
Now I'm trying my brand new HE2.

I will be back here in a few minutes :)

The problem with Ver7.1 was continuing to charge after the battery was fully charged. Something like a trickle of 20mA. Can you put an DMM set to amps between the battery and charger to see what it reads when the light goes green?

I will do this as soon as I can figure how to do :)

My brand new HE2 charged up to 4.16V too but, it's not a big deal, i put the VTC4 on accucell 6 and charge only 76mah.

I think i will use it anyway at least it's safer than my garbage ThrustFire charger.

V7.1 was worst than a trickle charge of 20mA.
It did not stop the charging process at all while having a CV of 4.5V.
It was an overcharging pos.



@joaomedina
A charger is suppose to stop the charging process when the current drop < ~0.1C of the programmed constant current.
It is not based on the battery voltage nor should it be.
Most chargers have an overvoltage protection tho, usually ~4.25V.
If your charger stop at 4.16V then the battery is full at that voltage.

20mA forever (Version 7.1)

Look at what a CV of 4.5V imply.
Current alone, by itself, is meaningless.
It need a potential difference between two point of a circuit in order to flow through.

The battery is saturated in energy but V7.1 keept trying to push more in it.
Would it have had a CV of 4.15V, and still did not terminate the process, at some point there would not have had any voltage difference to push the current.
It would had simply counter the self discharge of the battery without causing any major problems on short and mid terms.
Long term effect would had been a lost of capacity while doing nothing useful.

Fast charging with a higher CV come at a price, the batteries age faster.
Power wise, V7.1 did well in droping the current before reaching a current of 0.1C.
Keeping the CV the same and not terminating the charging process were huge flaws tho.

Note that the mAh shown in the graph above is based on the energy used to charge the battery, not the actual state of charge of the battery.
Most of the energy pass the ~4.2V mark are used up in fighting the battery in accepting more.
Altho it can give a rough aproximation of the charge state, the voltage of a battery tell nothing about its capacity.
Its maximum capacity is fixed by the chemistry and is unchangeable, charging a battery do not create new free lithium ions.

To use analogies, think of it as a glass filled with paint.

Emptying it will leave a film residu, at each filling/emptying cycle the paint will add to that film residu thickening it.
It represent the lost in capacity at each cycle.

Leaving the paint to dry in the glass and pour more in it to keep it full will create a crust on the surface.
At some point the crust will get thick enough to prevent attempt at emptying the glass.
This represent the lithium plating that occure on the anode when the charging process is never stop and there is still current being pushed through.
Not only does it affect the capacity permanently, the plated lithium bloc ions exchanges.
And on a relatively long term, or short term, depending on the CV used and chemistry type, short circuit the battery internally.

When a glass is full, you simply can not put more in it, no matter how hard you try.

I just measure the trickle in V8.0.
According to my cheap multimeter (Minipa ET-1005) it is 35mA after green LED comes on.

joaomedina wrote:

Crap it is even worse. Miller had claimed they fix this issue! What a shame.. A few versions ago they worked and cost less than 4 bucks. Now twice the money and no performance.

Unfortunately this charger will be leave aside just for trips and emergencies.

I wish I had found compact daily charger.