Opus BT C3100 - Weird behaviour when discharging

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Savydude
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Opus BT C3100 - Weird behaviour when discharging

Recently got a Opus BT C3100 which has some weird behaviour when using the discharging mode.

When it starts discharging the charger makes a reasonably loud clicking/ticking sound(starts before the fan switches on and carries on clicking during the whole discharge cycle) and it won't discharge cells(18650's in my case) to 2.8V. It took the 4 cells I used down to a range of 3.2v to 3.8v and then stopped discharging, tried twice. I tried the 500ma discharge rate and 200ma rate and it made no difference, with either mode the cells weren't discharged even close to 2.8V. I tried the supposedly discharged cells in my 400 lumen headlamp and they were still relatively full of juice.

 

Am I doing something wrong perhaps and is the clicking noise normal on the BT 3100 when discharging?

 

How does the selected discharge rate affect the discharge, if I select 500ma does it start the discharge at 500ma and gradually bring the current down over the discharge until the cell reaches 2.8v, or does the charger stop discharging the cell if it can't can't provide the required 500ma?

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Edited by: Savydude on 06/25/2017 - 13:58
Savydude
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Anyone have any idea on what's going on?

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chops728
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First off—The clicking sound you hear—Is the fan running/pulling air
Does it work right in the charging mode—sounds like the fan is obstructed or defective—-when this charger over heats it shuts down
When discharging it should hold close to the set discharge rate—- do you have any other cells you can try—try charging/discharging one cell — see what it does—also most of the time for 18650 cells I use the 1000ma setting—- In the charge mode — the charge rate will fluctuate as the cell gets closer to full charge— I have 2 Opus chargers—I have never experienced these problems—- only had clicking when one fan went bad

Savydude
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chops728 wrote:
First off--The clicking sound you hear--Is the fan running/pulling air Does it work right in the charging mode--sounds like the fan is obstructed or defective---when this charger over heats it shuts down When discharging it should hold close to the set discharge rate--- do you have any other cells you can try--try charging/discharging one cell -- see what it does--also most of the time for 18650 cells I use the 1000ma setting--- In the charge mode -- the charge rate will fluctuate as the cell gets closer to full charge-- I have 2 Opus chargers--I have never experienced these problems--- only had clicking when one fan went bad

 

As I mentioned in the OP the clicking starts immediately as the discharge mode is engaged, well before the fan starts spinning(when temps require it) and the fan is fine, the clicking/ticking sound only happens when discharging.

 

Just tested it again this afternoon and at "full" discharge the cells are at 3.47v/3.48v/3.75v/3.69v - something can't be right.

 

 

 

 

Have light will flash :)

HKJ
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Savydude wrote:

Just tested it again this afternoon and at “full” discharge the cells are at 3.47v/3.48v/3.75v/3.69v – something can’t be right.

That sounds correct enough.

My website with reviews of many chargers and batteries (More than 1000): http://lygte-info.dk/

Savydude
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HKJ wrote:
Savydude wrote:

Just tested it again this afternoon and at "full" discharge the cells are at 3.47v/3.48v/3.75v/3.69v - something can't be right.

That sounds correct enough.

 

How would that be the case, I thought the Opus discharged to 2.8V?

Did you notice the ticking sound during discharge when you tested this charger?

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chops728
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The only thing that could be making a clicking noise is the fan—the rest is just a circuit board—maybe one of the springs is making that noise or a shorting connection—do a charge test on 1 cell @ 1000 ma —see if the results is close to what the cell is rated at
My chargers are silent until the fan starts screaming

chops728
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Savydude wrote:

HKJ wrote:
Savydude wrote:

Just tested it again this afternoon and at “full” discharge the cells are at 3.47v/3.48v/3.75v/3.69v – something can’t be right.


That sounds correct enough.

 


How would that be the case, I thought the Opus discharged to 2.8V?


Did you notice the ticking sound during discharge when you tested this charger?

A cell will self charge back up some—not sure they go that high though

Lowtech
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Have no clicking in my charger as far as i know.

Only time it discharge stops higher then 2.8 – 3v is bad batteries that cant handle the discharge.

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chops728 wrote:
The only thing that could be making a clicking noise is the fan--the rest is just a circuit board--maybe one of the springs is making that noise or a shorting connection--do a charge test on 1 cell @ 1000 ma --see if the results is close to what the cell is rated at My chargers are silent until the fan starts screaming

 

The discharge circuit is separate from the charge circuit from what I understand, I've tried 500ma on the charge side and down to 200ma on the discharge program and it only/always makes the clicking noise on discharge, I'm thinking maybe a poor connection/device that's arcing in the discharge circuit somewhere.

 

chops728 wrote:
A cell will self charge back up some--not sure they go that high though

 

 

It does apparently trickle charge once the cell is discharged to 2.8, that's just so the cell doesn't go below 2.8v. I'm assuming the cell wouldn't bounce back much with a trickle charge, maybe it does but under normal circumstances I don't see it happening to that degree, 3.75v is an almost 1v jump from 2.8v.

 

Lowtech wrote:
Have no clicking in my charger as far as i know. Only time it discharge stops higher then 2.8 - 3v is bad batteries that cant handle the discharge.

 

The batteries are all laptop pulls that I use in my lights, they operate fine, should definitely be able to handle a 200ma discharge all the way down to 2.8v.

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chops728 wrote:
Savydude wrote:

HKJ wrote:
Savydude wrote:

Just tested it again this afternoon and at “full” discharge the cells are at 3.47v/3.48v/3.75v/3.69v – something can’t be right.


That sounds correct enough.

 


How would that be the case, I thought the Opus discharged to 2.8V?


Did you notice the ticking sound during discharge when you tested this charger?

A cell will self charge back up some—not sure they go that high though


At some point in time they changed the discharge voltage.
My older BT-c3100 V 2.1 is 2.8V
My <6months old BT-c3400 V 3.1 is 3.1V.

You stated above that yours is not old so it may be the 3.1V cut volt version.

As for the clicking sound, the fan is the only moving part so start with that.
If the clicking starts as soon as the discharge begins then disconnect the fan wires start a discharge and listen.
If it still clicks it can’t be good. If it stops you know the problem.

HKJ
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Savydude wrote:

HKJ wrote:
Savydude wrote:

Just tested it again this afternoon and at “full” discharge the cells are at 3.47v/3.48v/3.75v/3.69v – something can’t be right.


That sounds correct enough.

 


How would that be the case, I thought the Opus discharged to 2.8V?

It is usual 2.8V, but newer may be 3.1V.

A battery will recover voltage when the discharge stops, how much depends on the battery chemistry and the discharge current.

Savydude wrote:

Did you notice the ticking sound during discharge when you tested this charger?

No. The charger is pulsing the current and something may make a sound due to that.

My website with reviews of many chargers and batteries (More than 1000): http://lygte-info.dk/

bella-headlight
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As HKJ says the newer Opus discharge to 3.1v.
Once the discharge has stopped the cell will bounce back a bit from the 3.1v.
With the fact that you are using lap top pulls which have probably already seen a long hard life before you “pulled” them that could quite possibly be the reason you are seeing the voltages you are after discharge.
As to the “clicking” noise I have no idea.
Have you tried discharging a good new cell to see what voltage that shows after discharge as opposed to old laptop pulls ?

Ian

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  FWIW I put a full 30Q into my 3100 this morning on discharge.

 

No noise.  Resting voltage 3.24V after discharge.

Micha1982
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Got mine today and have the same fast clicking-noise here.

But not only on discharging, also when charging…when it is ready I open it and have a look inside….could take 1-2 days but I am interested what makes that annoying noise.

Savydude
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Micha1982 wrote:
Got mine today and have the same fast clicking-noise here. But not only on discharging, also when charging...when it is ready I open it and have a look inside....could take 1-2 days but I am interested what makes that annoying noise.

Did you discover anything?

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Savydude
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My charger has been seeing hard duty for the last month of so since this thread was started.

Noticed it only charges cells to a max of around 4.15V, probably better for cell longevity.

 

The cooling fan now is making a racket, is there any fix for that?

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