Charging battery problem

[jensenff]

Hi

First charge OK
second charge attempt:   Charger just click's green  and then off.  No red diode . 

Frequency abt' one every second.  I turned it off...
Anyone have a clue?

BR
VK 24

[e-lmer]

You did not say which charger, but it may be the charging
indicator.

On my charger the red light means a problem.

The flashing green is charging,
and the solid green is done.

Did you try measuring the voltage on the battery?

Do the lights do the same thing with or without the battery?

You know that you must plug the battery in before you
plug the charger in or the charger tries infinite voltage to
get the current to run on some kinds of chargers, right?

[Leslie]

You did not say which charger, but it may be the charging
indicator.

On my charger the red light means a problem.

The flashing green is charging,
and the solid green is done.

Did you try measuring the voltage on the battery?

Do the lights do the same thing with or without the battery?

You know that you must plug the battery in before you
plug the charger in or the charger tries infinite voltage to
get the current to run on some kinds of chargers, right?

That's an interesting subject.  On most regulators I build it is totally the opposite,  in one way this is correct, but in other ways it is not.  Charger should use good thermistors to restrict inrush when plugged into the wall then to the bike and charger should have protection diodes to stop inrush when it is not plugged into the wall then plugged into the battery.

The symptoms sound like a bad capacitor or charging switch fet on the switch mode, or barrier diode if they need them.  It worked before and now stumbles to make the high field required for charging.

Check if the voltage switch is set correct on the AC input.  220v or 110v.  If it is too high you may have damage problems if it is too low it may not charge properly..  

Check for a short circuit in the in the plugs or water in the plug can make the charger behave badly.

[jensenff]

Hi again

More details: 

Charger came with the battery, 36V12Ah.  The charger is AC input 100-240V  ( no selection needed).  Output is 40V 1.8A  DC
The indicator is on the charger.  It says green=finish or not connected.  Red = charging.  It type is SANS Electronics
First charge it behaved as it should.
Battery is not empty, measure 39.47V   both on output terminal and on charge input.

No moisture , no short found.  I did check the charger not connected to the battery:  It should have green steady light, but does flash green.  When connecting it to battery, it continues to flash, and start making relay - clicking sounds

I feel I have a bad charger.  I must have killed it somehow.   It is brand new.  I've asked Tom what to do.. 


BR
VK24

[Cornelius]

Please report back to us about your response from Tom.

My brother has exactly the same problem with his charger bought recently...

[jensenff]

Will do!  Not good news there is one more charger not working , recently bought.

[Onetom2]

Will do!  Not good news there is one more charger not working , recently bought.

It seems strange that so many have bought new charges and get the same problem, should that point to something else as the problem, like inside the battery pack?

[jensenff]

Hi
Considering forum - messages with similar topic: Lot of (new) chargers defective, reason unknown.
My self - bought new charger arrived today.  My 36V - pack was badly in need for charge, and is now charging. (3.8.2010, 14:53, UTC+2) New charger seems ok so far.

Reason?  :  still unknown.  Any ideas out there?
- The defective charger was OK for my initial charge
- One detail :  I removed the charger from the battery BEFORE it was finished,  eg RED diode and still charging.
- Next use of charger -->  dead, or output switching between 0V - abt 10V.  Clicking sound when battery connected. Led - indicator blinking at the same time
- I've asked Tom what to do with my defective unit;  Claim warranty.  No answer yet
- I've asked Tom if there is a sequence to follow  ;  connect charger to mains first, then to battery  or the other way around.  Prompt answer from Tom,  just connect it!  No sequence mentioned.

I will surly not disconnect the charger before it has finished this time...
I consider opening my defective charger to check it;  My repair - skills are a bit rusty...

[Leslie]

Hi
Considering forum - messages with similar topic: Lot of (new) chargers defective, reason unknown.
My self - bought new charger arrived today.  My 36V - pack was badly in need for charge, and is now charging. (3.8.2010, 14:53, UTC+2) New charger seems ok so far.

Reason?  :  still unknown.  Any ideas out there?
- The defective charger was OK for my initial charge
- One detail :  I removed the charger from the battery BEFORE it was finished,  eg RED diode and still charging.
- Next use of charger -->  dead, or output switching between 0V - abt 10V.  Clicking sound when battery connected. Led - indicator blinking at the same time
- I've asked Tom what to do with my defective unit;  Claim warranty.  No answer yet
- I've asked Tom if there is a sequence to follow  ;  connect charger to mains first, then to battery  or the other way around.  Prompt answer from Tom,  just connect it!  No sequence mentioned.

I will surly not disconnect the charger before it has finished this time...
I consider opening my defective charger to check it;  My repair - skills are a bit rusty...

Please open it. Take some pic and do share.

Edit.

Important.  Please leave the charger unpluged from mains for a little while before opening to make sure the mains capacitors are discharged.  They can give you a bit of a jolt if they have remaining charge in them.

Do this at your own risk.

[Cornelius]

I've opened my brothers and poked a bit around with a multimeter; both with and without power...
Visually, there's no fault; no bad soldering etc. (none too bad, anyway ... I'm not that good with switched psu's, but I traced the pulsing power to the primary side of the psu; the high-voltage side pulsates from 0V to around 600V +/-...

This charger are the same as Jensen's, with the same symptoms...

[jensenff]

hi. I've stopped trying to find the error. Primary side seemed ok.  probably feedback too quick, shutdown before stabillizing 42 some volts.  I managed to shortcut the poweric before findining the real cause.. Went totally dead ofcource. I got my new charger from china, still ok. New order charger, not on warranty.   I will make my own , spare  charrger just in case.

[karen]

I bought both the 36 and 48v battery and charger. One didnt work but both had a fuse. I changed the fuse from the one working to the other one and then it worked. Could not see anything wrong with the fuse, but the one working I put in the charger I need.