Problem with regulation of Fenix E20

[Swedpat]

I really like this modern "successor of the Mini Maglite". Bright with a long runtime and comfortable to hold. Something is wrong with it, however. After a while, within an hour of use the brightness will significantly decrease. It starts after a second or two after put it on, and then instantly the brightness level fall down to much lower, I could estimate half of the normal. I use recheargable 2700mAh NiMh cells.
This flashlight shall provide +3 hours of constant brightness using such batteries, but not mine.

Regards, Patric.

 

[Rossymeister]

What brand of NiMH are you using?

 

[Marduke]

Sounds like worn out cells.

 

[Swedpat]

When I check the batteries I see that these two are not 2700mAh, but 2500. That would not be a deciding factor anyway. The brand is Vanson.
The reason I thought I had 2700mAh cells is that I have several of GP 2700mAh, and also Duracell 2650mAh, to other applications.

Regards, Patric

 

[sol-leks]

yeah try a new pair of rechargeables

 

[Marduke]

All the 2500 cells out there have proven to be less than stellar (some less so than others), so yeah, your best bet is to use good cells.

 

[Rossymeister]

I recommend upgrading to some Eneloops

 

[Rossymeister]

Could it also be possible that your charger isnt fully charging the batteries?

 

[Swedpat]

I will make a new try with a pair of GP 2700mAh cells. My charger is a GP model GPPB60, which has an individual charging of every cell and can charge any number of cells between 1-4. It has a display which shows the charging status and stop the charging when the cells are fully charged.
None of my cells are charged even 20 times so the cells cannot be too much used, and I am careful to discharge the cells before every new charging.

Regards, Patric

 

[Marduke]

I will make a new try with a pair of GP 2700mAh cells. My charger is a GP model GPPB60, which has an individual charging of every cell and can charge any number of cells between 1-4. It has a display which shows the charging status and stop the charging when the cells are fully charged.
None of my cells are charged even 20 times so the cells cannot be too much used, and I am careful to discharge the cells before every new charging.

Regards, Patric

That could be your problem. Some cells (especially the 2500 series) are VERY sensitive to over discharge. You don't need to discharge your cells for every cycle. That came from the old NiCad days and is no longer necessary.

Edit: When charging only 1 or 2 cells, that charger also seems a touch heavy handed on the charging current, which can be hard on weak cells. I would waiting to charge until you have 3 or 4 cells ready, so the charge current is a bit lower.

 

[kramer5150]

and I am careful to discharge the cells before every new charging.

Regards, Patric

Thats your problem I think... NimH cells can be sensitive to over discharge. You can rapidly shorten their lifespan and reduce their capacity with repeated over-discharging. You don't need to discharge them fully every time, because the chemistry does not have "cell memory". That was something that plagued nicads, and the solution was to make sure they were thoroughly (but not overly) discharged when stored for long periods without use.

 

[Swedpat]

Thanks for your advices!

I understand that I have made a mistake by discharge the cells until the flashlight is dead...

What is the best; shall I recharge the cells as soon the flashlight starts to significantly dim? Or is it even ok to recharge as soon I notice any decreasing of the brightness?

Regards, Patric

 

[Marduke]

Do you use the light on a regular basis?

Say you can generally go every 2 weeks on a charge. It might be a good idea to charge up every week so you always have a good charge left on your cells.

 

[Swedpat]

Marduke,

It can vary. Sometimes every day, often just for fun...
Do you mean it's ok to recharge the cells regularly even if they are not used more than partly of the usable runtime with high output?

Regards, Patric

 

[Marduke]

Marduke,

It can vary. Sometimes every day, often just for fun...
Do you mean it's ok to recharge the cells regularly even if they are not used more than partly of the usable runtime with high output?

Regards, Patric

Yes, it's fine to just top off cells periodically. If you have used the light a decent bit, and it's convenient to do so, go ahead and top off the cells.

 

[NewFenix]

Hi all, new to forum, appreciate all your helpfulness and hope you can help me. I just bought/received an Fenix E20 and have the same problem with regular 1.5 v AA batteries, or with my rechargeables. 5 minutes of beautiful brightness and then dimming until useless. Brand new, out the box this problem. any suggestions for me? I would greatly appreciate it because I am traveling, it would cost me the price of a new one just to ship it back.