Turnigy Accucell-6...Am I missing something?

[KiwiMark]

Has anyone tried to calibrate the volt-meter to -.15v to trick the charger into charging the 4.35v Samsung ICD-18650-30a?

Good idea, but the calibration doesn't let you change the voltage by that much, you'd be pushing to get as much as -0.05V with the calibration for a maximum of 4.25V.

Some chargers offer more settings - the iChargers can charge to 4.30V, so if you calibrated one of them to -0.05V out and then set the LiPo charge to 4.30V you would get 4.35V, you could then set the LiIo charge to 4.15Va and you would get 4.20V on that setting and you could set the LiFe charge to 3.55V and get 3.60V with that. That would work really well for all Li-ion cells.

On the Accucell, even if you could alter the calibration by -0.15V (which I am certain you can't), then your Li-Io setting would become 4.25V instead of 4.10V and your LiFe setting would give you 3.75V instead of 3.60V - so you'd need to recalibrate every time you charged a different type of battery.

 

[hellokitty[hk]]

Then I assume the imax b6 and all those other bantam chargers are all too limited too...
Can I ask if there are an cheap (<$30 USD) that would accommodate 4.35v?

 

[dizhu]

So, once you have brought it up to 3.6V then what happens when you try to charge it with the LiPo or LiIo setting?

Yeah, that is what I figured out. Have to change the program once the battery voltage is up.

 

[dizhu]

Has anyone tried to calibrate the volt-meter to -.15v to trick the charger into charging the 4.35v Samsung ICD-18650-30a?

How to bring up the calibration menu? I don't know how.

 

[45/70]

I just got one and tried to charge my depleted IMR 26500. The screen shows voltage too low and refuse to charge. Only I change to LiFe mode and it starts charging. But that only give me 3.6 charged. Any suggestion?

My advice would be to pitch the cell. The reason the Accucel displays this warning, is because the cell has been discharged to too low a level, and thus has been damaged, and should not be charged. This feature that hobby chargers provide is there for a purpose, not just to annoy the user. Sure you may find a way to circumvent this warning, but you'd be better off just recycling the cell. This is especially true if the cell remained in the over discharged state for any length of time.

Just like LiCo cells, IMR (LiMn) cells (as well as LiFePO4 cells and all of the other Li-Ion chemistries) are damaged when subjected to over discharge. They may not "vent with flame" as easily as a LiCo cell might, when charged, but the danger is still there when cells have been abused. The IMR chemistry is "safer", not actually "safe", as many dealers and distributors like to call them. At any rate, over discharged Li-Ion cells of any chemistry have been damaged to some degree, and it's better to just replace and move on.

Dave

 

[PapaLumen]

How to bring up the calibration menu? I don't know how.

Press and hold "<" and "start" together while powering on the charger, keep holding until calibration adjustment appears.

 

[dizhu]

Press and hold "<" and "start" together while powering on the charger, keep holding until calibration adjustment appears.

Thanks. Adjusted to +20 now.

 

[dizhu]

My advice would be to pitch the cell. The reason the Accucel displays this warning, is because the cell has been discharged to too low a level, and thus has been damaged, and should not be charged. This feature that hobby chargers provide is there for a purpose, not just to annoy the user. Sure you may find a way to circumvent this warning, but you'd be better off just recycling the cell. This is especially true if the cell remained in the over discharged state for any length of time.

Just like LiCo cells, IMR (LiMn) cells (as well as LiFePO4 cells and all of the other Li-Ion chemistries) are damaged when subjected to over discharge. They may not "vent with flame" as easily as a LiCo cell might, when charged, but the danger is still there when cells have been abused. The IMR chemistry is "safer", not actually "safe", as many dealers and distributors like to call them. At any rate, over discharged Li-Ion cells of any chemistry have been damaged to some degree, and it's better to just replace and move on.

Dave

Wow, my new IMR batteries all gone

The thing is that the flashlight cuts off when each battery reaches around 2.3 V. Before that it is hard to know how low it is. Is there way I can buy parts and add a protection circuit to my Mag 2C? Suggestion anyone?

 

[45/70]

Wow, my new IMR batteries all gone

The thing is that the flashlight cuts off when each battery reaches around 2.3 V.

Well, don't panic yet. If the light cuts out when the cell voltage is 2.3 Volts under load, you may be OK. What is puzzling here though, is that when cells are used under all but light current loads, the cell's voltage should recover to a voltage level (typically 3.0 Volts, or more) after resting a bit, where your Accucel will charge it. The only condition where this wouldn't be the case, is when a cell is discharged at a low current rate. In this situation the cell may be discharged to an unacceptable level and the voltage may not recover.

This is a problem with cells that include an added protection circuit, as well. Unlike most laptops and other consumer devices that utilize Li-Ion battery packs, where the protection circuit is designed specifically for that device's usage habits, the protection circuits added to individual Li-Ion cells by distributors, cannot accurately predict how the cell will actually be used. In many cases, under low current usage, the protection circuit on protected cells will not trip in time either, to prevent over discharge.

If you think this may be your problem, what you might try, if you tend to use your light(s) at low output levels quite a bit, is occasionally bump the output up to max, during use. If, when you crank up the output, your light cuts off, you'll know that the cell is discharged. This may help over discharging the cells some, anyway. I do this with my Li-Ion powered lights, and it at least helps, in this situation. On the other hand, when I use a light, I usually want "light", so I don't normally use them at lower output levels very much, but rather use a light with less maximum output when needed for long periods, instead.

Dave

 

[stoli67]

I love my accucell 6. .... If only you could turn the speaker off! So loud.... One beep may have been enough

Is there a reason to charge in parallel over a serial setup like I have been using?

 

[KiwiMark]

I love my accucell 6. .... If only you could turn the speaker off! So loud.... One beep may have been enough

There is a setting - you CAN turn the speaker off.

 

[stoli67]

I will have to look harder obviously!


EDIT: Much better with the speaker off.....

 

[HKJ]

Is there a reason to charge in parallel over a serial setup like I have been using?

The parallel setup is usual faster with unbalanced cells (The balancing function is often only at a low current).
A more practical reason is that a parallel cradle can be used for any number of cells, up to capacity, without moving any wires.

 

[Nisei]

I'm thinking about buying this not for charging but for measuring the capacity of my Li-ion batteries.
The LiPo mode charges to 4.2 which is correct for Li-ion but it discharges to 3.0V which is too low for my liking. Can the low voltage termination be set to 3.2V for this mode?

 

[torukmakto4]

I believe you can use NiMH Discharge and set the cutoff voltage to whatever you want. (WARNING: Risk of :poof:. Be careful to check settings and not accidentally use NiMH Charge or Cycle on the Li-ion cells after doing this!)

Also, what cells do you have? I would only worry about 3.0V/cell being stressful for straight LiCo cells with a stated 3.0V cutoff voltage in the datasheet.

 

[Nisei]

Thanks for the response torukmakto4
I'm going to use it with my Sanyo UR14500P and Panasonic 18650B batteries.
I'm aware of the need to check the correct settings. I just didn't know for sure if there's a way to set the discharge low current cut off. If it's possible with this charger then it seems like it's what I'm looking for.

 

[Nisei]

Oh by the way, has anyone tried this? I mean, when you set it to NiMH discharge mode it expects a voltage of around 1.2V
Connecting a Li-ion battery would be 3 times as much. It shouldn't make a difference for discharging but does the charger accept that voltage in NiMH mode?

 

[torukmakto4]

NiMH discharge is for packs. The charger is rated to charge and discharge 15 cell series packs. You can set the cutoff voltage for NiMH Discharge between 0.1V and 25V.

More here: http://www.hobbyking.com/hobbyking/store/uploads/ACCUCEL_manual(2).pdf

 

[Nisei]

Yup, saw that later on as well :)
i was thinking 1-cell only but it can go up to 15 so my post made no sense. Thanks for responding.

 

[Nisei]

Another question now that I've received it:
I want to test the Storage mode and have it set for Li-Ion (not Li-Po) giving a 3.75 cut off voltage. The battery I want to charge for storage was first discharged to 3.0V so there's no need for the program to discharge first.
The battery is 900mAh and I have set the charge rate to 0.4A. However, when I run the program it soon drops down to 0.1A charge rate which is way too low. It's been on for an hour and a half now and has only charged something in the 200mA range. Since it doesn't display the actual battery voltage in Storage mode I have no idea why it throttles down to such a low rate. Why does it drop down to 0.1A while I have it set for 0.4A?
And I was thinking: storage is best at around 50% capacity. However, the charger can only determine this by measuring the voltage. If you discharge a Li-Ion to 3V it will soon climb back up 3.6V or so. So how can the charger know how full the battery already is?