Hi,

In an attempt to restore a pair of sulphatated Trojan T105 batteries I
ordered a desulphator kit, soldered it together and hooked it up to
the batteries. After it had been pulsing for a week and a half, the
batteries needed to be recharged (the pulser is powered by the
batteries). I connected my nice CTEK 15 A charger WITH THE PULSER
STILL ATTACHED to the batteries. I'm afraid this was a mistake. In my
understanding, the batteries should absorb the peaks produced by the
pulser and not damage the charger. However, now it seems that my
charger is only outputting 17.0 volts (always) and heavily
overcharging any battery that I connect it to. The peaks from the
pulser might have been higher than I thought.

I opened the casing of the charger, but couldn't any component that
looked fried. Can anyone tell me where to start looking for the
defective component? It is quite a complicated microcontroller
controlled charger, but I still have some hope that there is a single
component that needs replacement for it to start functioning properly
again.

Many thanks,
Joost

On Sun, 25 Mar 2012 13:18:24 -0700 (PDT), joost
put finger to keyboard and composed:

However, now it seems that my
charger is only outputting 17.0 volts (always) and heavily
overcharging any battery that I connect it to.

I'm not familiar with your charger, but I would look for a device, eg
a MOSFET, in series with the output.

A photo of the innards might help.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

On 3/25/2012 1:18 PM, joost wrote:
Hi,

In an attempt to restore a pair of sulphatated Trojan T105 batteries I
ordered a desulphator kit, soldered it together and hooked it up to
the batteries. After it had been pulsing for a week and a half, the
batteries needed to be recharged (the pulser is powered by the
batteries). I connected my nice CTEK 15 A charger WITH THE PULSER
STILL ATTACHED to the batteries. I'm afraid this was a mistake. In my
understanding, the batteries should absorb the peaks produced by the
pulser and not damage the charger. However, now it seems that my
charger is only outputting 17.0 volts (always) and heavily
overcharging any battery that I connect it to. The peaks from the
pulser might have been higher than I thought.

I opened the casing of the charger, but couldn't any component that
looked fried. Can anyone tell me where to start looking for the
defective component? It is quite a complicated microcontroller
controlled charger, but I still have some hope that there is a single
component that needs replacement for it to start functioning properly
again.

Many thanks,
Joost
There are lots of claims made by desulphator vendors. I've never read
anything, outside the vendor sphere of information, that said they
worked at all. My experiments agree that they don't work.
I assume you wired the desulphator correctly?

The symptom of a sulphated battery is high internal resistance.
One theory is that if you put a huge voltage spike into the battery,
you can dislodge or reverse the sulphation.

One measure of the progress of desulphation is to watch the
amplitude of the spikes go down as the process proceeds.
In my experiments, I never saw any reduction in spike amplitude
and never experienced any improvement in ability to take/deliver charge.

So, if your batteries are sulphated, you'll see high voltage spikes.
Only a good battery could absorb the spikes...in which case you'd not
need a desulphator.

Sounds like you shorted whatever controls the charge current in your
charger.
May be a FET or SCR.
Is there any activity on the lights on power up that suggests the
logic might still be working? I assume you checked for a fuse
somewhere in the logic supply? If the pulser jacked the VCC up to
the peak of the voltage spikes, you probably fried the whole thing.

Not clear what charger you have, so downloading the manual is ineffective.
Without schematics, or an understanding of battery chargers that you
don't appear to have, it's gonna be difficult to fix it.

You're probably going to want to probe around in it live with an
oscilloscope.
Looks like an offline converter that can be dangerous to service without
proper equipment (AKA You get dead).

On 3/25/2012 2:40 PM, mike wrote:
On 3/25/2012 1:18 PM, joost wrote:
Hi,

In an attempt to restore a pair of sulphatated Trojan T105 batteries I
ordered a desulphator kit, soldered it together and hooked it up to
the batteries. After it had been pulsing for a week and a half, the
batteries needed to be recharged (the pulser is powered by the
batteries). I connected my nice CTEK 15 A charger WITH THE PULSER
STILL ATTACHED to the batteries. I'm afraid this was a mistake. In my
understanding, the batteries should absorb the peaks produced by the
pulser and not damage the charger. However, now it seems that my
charger is only outputting 17.0 volts (always) and heavily
overcharging any battery that I connect it to. The peaks from the
pulser might have been higher than I thought.

I opened the casing of the charger, but couldn't any component that
looked fried. Can anyone tell me where to start looking for the
defective component? It is quite a complicated microcontroller
controlled charger, but I still have some hope that there is a single
component that needs replacement for it to start functioning properly
again.

Many thanks,
Joost
There are lots of claims made by desulphator vendors. I've never read
anything, outside the vendor sphere of information, that said they
worked at all. My experiments agree that they don't work.
I assume you wired the desulphator correctly?

The symptom of a sulphated battery is high internal resistance.
One theory is that if you put a huge voltage spike into the battery,
you can dislodge or reverse the sulphation.

One measure of the progress of desulphation is to watch the
amplitude of the spikes go down as the process proceeds.
In my experiments, I never saw any reduction in spike amplitude
and never experienced any improvement in ability to take/deliver charge.

So, if your batteries are sulphated, you'll see high voltage spikes.
Only a good battery could absorb the spikes...in which case you'd not
need a desulphator.

Sounds like you shorted whatever controls the charge current in your
charger.
May be a FET or SCR.
Is there any activity on the lights on power up that suggests the
logic might still be working? I assume you checked for a fuse
somewhere in the logic supply? If the pulser jacked the VCC up to
the peak of the voltage spikes, you probably fried the whole thing.

Not clear what charger you have, so downloading the manual is ineffective.
Without schematics, or an understanding of battery chargers that you
don't appear to have, it's gonna be difficult to fix it.

You're probably going to want to probe around in it live with an
oscilloscope.
Looks like an offline converter that can be dangerous to service without
proper equipment (AKA You get dead).



Just found the model number in the subject line.
Manual says it has a built-in desulphator.
Why did you add a second one?

On Sun, 25 Mar 2012 14:40:56 -0700, mike wrote:

There are lots of claims made by desulphator vendors. I've never read
anything, outside the vendor sphere of information, that said they
worked at all. My experiments agree that they don't work.

I agree. I maintain several mountain top radio and weather station
sites, all on various mutations of battery power. Various experts
have arrived with desulphators and magic anti-sulphation potions
(EDTA), none of which have done anything beyond a short term revival.

One problem is that none of the articles I've read that proclaim
miraculous battery rejuvenation bother to run before and after tests.
I have a West Mountain Radio CBA-II battery tester.
http://www.westmountainradio.com/product_info.php?products_id=cba3&navcode=/cbaLink1
With a 10A discharge rate, the L16 batteries that I usually use (2V
465A-hr) take about 4 days to hit the knee in the curve. Your T105
(6V 225A-hr) should take about 2 days. However, that's with a new
battery. What I've found is that a pre-treatment battery, may have
about 1/4th of it's original capacity, while a post treatment battery
will have even less. The post treatment battery will "take a charge"
better than one that seems sulphated, but the discharge capacity isn't
there.

Diversion: When you discharge a wet cell battery, you solve the lead
plates into the electrolyte solution. When you charge the battery,
you electroplate the lead back onto the plates. It never quite goes
on the same way it came off. Do it often enough, or too fast, and the
lead plates start looking like a coral reef with attendant loss of
capacity.

What's happening is the result of doing a post mortem on only one
battery, so this is admittedly rather anecdotal. What desulfation
does is remove the coating of lead sulphate from the lead plates.
That's fine, except that by the time the battery becomes sulphated,
the normally porous (sintered) lead plates, now look rather like a
coral reef. Exposing more of the lead plate surface should will
improve the ability to take a charge, but the discharge is still at
the mercy of the lack of sufficient surface area, and that's going to
be as bad or worse than what you started. Worse, the shock treatment
of de-sulfation can cause chunks of lead sulphate to fall off the
surface of the lead plates and fall to the bottom (i.e. deep cycle),
taking some of the coral reef looking lead to go with it. The
reduction in the amount of lead in the battery plates will have a
detrimental effect on future charge/discharge cycles.

Links to a typical crude desulphators:
http://homepower.com/view/?file=HP77_pg84_Couper
http://home.comcast.net/~ddenhardt201263/desulfator/desulf.htm

Good battery advice:
http://batteryuniversity.com/learn/article/sulfation_and_how_to_prevent_it
http://batteryuniversity.com

As for connecting two charger in parallel, you're lucky that one of
the chargers didn't blow a fuse, or an internal component. Don't do
that again. If you RTFM at:
http://www.baintech.com.au/download-document/37-ctek-xs-15000-user-manual
it says:
"Do not place the charger on the battery while charging"

You're probably going to want to probe around in it live with an
oscilloscope.
Looks like an offline converter that can be dangerous to service without
proper equipment (AKA You get dead).

I couldn't find a schematic of the CTEK MULTI XS 15000 which might
help with a repair. On paper, it looks like a really nice battery
charger. My guess(tm) is that the desulfation contrivance is capable
of producing some rather high voltage pulses. Those could easily have
destroyed whatever output power FET's are inside.

Make and model of the desulfation device?

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

I am sceptical about the desulphator, but as a new set of batteries
costs me
300 euro, I thought, let's give that 30 euro kit a try. Of course not
knowing that it would kill my 200 euro charger...
To get some more info on my spikes, I just connected a capacitor and
a
diode. It showed 62 volts. Oops. This must certainly have been the
cause of
my charger problem.

The logic of the charger seems to be fine and looking at the amount
of
gassing it also seems to be putting out plenty of current. I did saw
at
least one FET inside and will go and check out that one and others
that I
can find. I tried to find a schematic, but couldn't.

The funny thing indeed is that this charger has a built in
desulphator. This
also led me to think that desulphators could work. If a reliable
manufacturer like CTek is building it into its chargers... The problem
that
is that the CTEK only stays in desulphation mode for about 5 seconds.
I
cannot imagine this to be effective at all. Therefore a tried the
desulphator
kit.

The desulphator comes from Courtiestown:
http://www.courtiestown.co.uk/batter...ust%202011.pdf

Thank you all for your comments. I hope I'm lucky and can get it
running again. Will keep an eye on the peak voltage of the desulphator
too, to see if mine is perhaps dropping.

Joost

On 26 mrt, 01:44, Jeff Liebermann wrote:
On Sun, 25 Mar 2012 14:40:56 -0700, mike wrote:
There are lots of claims made by desulphator vendors. *I've never read
anything, outside the vendor sphere of information, that said they
worked at all. *My experiments agree that they don't work.

I agree. *I maintain several mountain top radio and weather station
sites, all on various mutations of battery power. *Various experts
have arrived with desulphators and magic anti-sulphation potions
(EDTA), none of which have done anything beyond a short term revival.

One problem is that none of the articles I've read that proclaim
miraculous battery rejuvenation bother to run before and after tests.
I have a West Mountain Radio CBA-II battery tester.
http://www.westmountainradio.com/product_info.php?products_id=cba3&na....
With a 10A discharge rate, the L16 batteries that I usually use (2V
465A-hr) take about 4 days to hit the knee in the curve. *Your T105
(6V 225A-hr) should take about 2 days. *However, that's with a new
battery. *What I've found is that a pre-treatment battery, may have
about 1/4th of it's original capacity, while a post treatment battery
will have even less. *The post treatment battery will "take a charge"
better than one that seems sulphated, but the discharge capacity isn't
there.

Diversion: *When you discharge a wet cell battery, you solve the lead
plates into the electrolyte solution. *When you charge the battery,
you electroplate the lead back onto the plates. *It never quite goes
on the same way it came off. *Do it often enough, or too fast, and the
lead plates start looking like a coral reef with attendant loss of
capacity.

What's happening is the result of doing a post mortem on only one
battery, so this is admittedly rather anecdotal. *What desulfation
does is remove the coating of lead sulphate from the lead plates.
That's fine, except that by the time the battery becomes sulphated,
the normally porous (sintered) lead plates, now look rather like a
coral reef. *Exposing more of the lead plate surface should will
improve the ability to take a charge, but the discharge is still at
the mercy of the lack of sufficient surface area, and that's going to
be as bad or worse than what you started. *Worse, the shock treatment
of de-sulfation can cause chunks of lead sulphate to fall off the
surface of the lead plates and fall to the bottom (i.e. deep cycle),
taking some of the coral reef looking lead to go with it. *The
reduction in the amount of lead in the battery plates will have a
detrimental effect on future charge/discharge cycles.

Links to a typical crude desulphators:
http://homepower.com/view/?file=HP77_pg84_Couper
http://home.comcast.net/~ddenhardt201263/desulfator/desulf.htm

Good battery advice:
http://batteryuniversity.com/learn/article/sulfation_and_how_to_preve...
http://batteryuniversity.com

As for connecting two charger in parallel, you're lucky that one of
the chargers didn't blow a fuse, or an internal component. *Don't do
that again. *If you RTFM at:
http://www.baintech.com.au/download-document/37-ctek-xs-15000-user-ma...
it says:
* *"Do not place the charger on the battery while charging"

You're probably going to want to probe around in it live with an
oscilloscope.
Looks like an offline converter that can be dangerous to service without
proper equipment (AKA You get dead).

I couldn't find a schematic of the CTEK MULTI XS 15000 which might
help with a repair. *On paper, it looks like a really nice battery
charger. *My guess(tm) is that the desulfation contrivance is capable
of producing some rather high voltage pulses. *Those could easily have
destroyed whatever output power FET's are inside.

Make and model of the desulfation device?

--
Jeff Liebermann * *
150 Felker St #D * *http://www.LearnByDestroying.com
Santa Cruz CA 95060http://802.11junk.com
Skype: JeffLiebermann * * AE6KS * *831-336-2558

Hi,

It is all not so very accessible inside the charger. I identified at
least one IRF1405 FET. There is second one which might be the same
type. Then there are two larger boxes also attached to the heatsink.
Three heavy legs. One has the writing D4 on the PCB and the other one
D4A. Could these be the SCRs that you mentioned? Are these sensitive
to voltage spikes too?

Joost.

On 25 mrt, 23:40, mike wrote:
On 3/25/2012 1:18 PM, joost wrote:

Hi,

In an attempt to restore a pair of sulphatated Trojan T105 batteries I
ordered a desulphator kit, soldered it together and hooked it up to
the batteries. After it had been pulsing for a week and a half, the
batteries needed to be recharged (the pulser is powered by the
batteries). I connected my nice CTEK 15 A charger WITH THE PULSER
STILL ATTACHED to the batteries. I'm afraid this was a mistake. In my
understanding, the batteries should absorb the peaks produced by the
pulser and not damage the charger. However, now it seems that my
charger is only outputting 17.0 volts (always) and heavily
overcharging any battery that I connect it to. The peaks from the
pulser might have been higher than I thought.

I opened the casing of the charger, but couldn't any component that
looked fried. Can anyone tell me where to start looking for the
defective component? It is quite a complicated microcontroller
controlled charger, but I still have some hope that there is a single
component that needs replacement for it to start functioning properly
again.

Many thanks,
Joost

There are lots of claims made by desulphator vendors. *I've never read
anything, outside the vendor sphere of information, that said they
worked at all. *My experiments agree that they don't work.
I assume you wired the desulphator correctly?

The symptom of a sulphated battery is high internal resistance.
One theory is that if you put a huge voltage spike into the battery,
you can dislodge or reverse the sulphation.

One measure of the progress of desulphation is to watch the
amplitude of the spikes go down as the process proceeds.
In my experiments, I never saw any reduction in spike amplitude
and never experienced any improvement in ability to take/deliver charge.

So, if your batteries are sulphated, you'll see high voltage spikes.
Only a good battery could absorb the spikes...in which case you'd not
need a desulphator.

Sounds like you shorted whatever controls the charge current in your
charger.
May be a FET or SCR.
Is there any activity on the lights on power up that suggests the
logic might still be working? *I assume you checked for a fuse
somewhere in the logic supply? *If the pulser jacked the VCC up to
the peak of the voltage spikes, you probably fried the whole thing.

Not clear what charger you have, so downloading the manual is ineffective..
Without schematics, or an understanding of battery chargers that you
don't appear to have, it's gonna be difficult to fix it.

You're probably going to want to probe around in it live with an
oscilloscope.
Looks like an offline converter that can be dangerous to service without
proper equipment (AKA You get dead).

On 3/26/2012 12:32 PM, joost wrote:
Hi,

It is all not so very accessible inside the charger. I identified at
least one IRF1405 FET. There is second one which might be the same
type. Then there are two larger boxes also attached to the heatsink.
Three heavy legs. One has the writing D4 on the PCB and the other one
D4A. Could these be the SCRs that you mentioned? Are these sensitive
to voltage spikes too?

Joost.

On 25 mrt, 23:40, wrote:
On 3/25/2012 1:18 PM, joost wrote:

Hi,

In an attempt to restore a pair of sulphatated Trojan T105 batteries I
ordered a desulphator kit, soldered it together and hooked it up to
the batteries. After it had been pulsing for a week and a half, the
batteries needed to be recharged (the pulser is powered by the
batteries). I connected my nice CTEK 15 A charger WITH THE PULSER
STILL ATTACHED to the batteries. I'm afraid this was a mistake. In my
understanding, the batteries should absorb the peaks produced by the
pulser and not damage the charger. However, now it seems that my
charger is only outputting 17.0 volts (always) and heavily
overcharging any battery that I connect it to. The peaks from the
pulser might have been higher than I thought.

I opened the casing of the charger, but couldn't any component that
looked fried. Can anyone tell me where to start looking for the
defective component? It is quite a complicated microcontroller
controlled charger, but I still have some hope that there is a single
component that needs replacement for it to start functioning properly
again.

Many thanks,
Joost

There are lots of claims made by desulphator vendors. I've never read
anything, outside the vendor sphere of information, that said they
worked at all. My experiments agree that they don't work.
I assume you wired the desulphator correctly?

The symptom of a sulphated battery is high internal resistance.
One theory is that if you put a huge voltage spike into the battery,
you can dislodge or reverse the sulphation.

One measure of the progress of desulphation is to watch the
amplitude of the spikes go down as the process proceeds.
In my experiments, I never saw any reduction in spike amplitude
and never experienced any improvement in ability to take/deliver charge.

So, if your batteries are sulphated, you'll see high voltage spikes.
Only a good battery could absorb the spikes...in which case you'd not
need a desulphator.

Sounds like you shorted whatever controls the charge current in your
charger.
May be a FET or SCR.
Is there any activity on the lights on power up that suggests the
logic might still be working? I assume you checked for a fuse
somewhere in the logic supply? If the pulser jacked the VCC up to
the peak of the voltage spikes, you probably fried the whole thing.

Not clear what charger you have, so downloading the manual is ineffective.
Without schematics, or an understanding of battery chargers that you
don't appear to have, it's gonna be difficult to fix it.

You're probably going to want to probe around in it live with an
oscilloscope.
Looks like an offline converter that can be dangerous to service without
proper equipment (AKA You get dead).


Output SCR's go with battery chargers having huge transformers.

Your smart charger probably is a straight forward converter with logic
built around the current and voltage sense to control it.
The good news is that it sounds like the charging path is working.
Bad news is that you probably broke something hooked to the output to sense
voltage and current. Follow the signal path from the + and - output
terminals back to some IC. That's probably what you broke...maybe...
There are lots of ways to do this function. Hard to know what to expect
knowing nothing about it.

The things labeled D are probably diodes.

You need an oscilloscope and an Isolation Transformer,
and someone who knows how to use both, to work on this thing.

Don't underestimate the potential of this thing to hurt you.
You don't have to get electrocuted. All you need to do is go
flying across the room and land on the corner of a desk.

Wear safety glasses. I scratched a cornea in a freak accident
when I came flying out the back of a TV set I was working on.
And I've still got scars where a slip of a probe caused a FET
to explode in my face. There's a lot of energy in a tiny space.
Be respectful.

I've avoided using desulfators with any of my intelligent chargers for the
very reason that you've experienced.

BTW, something that seems kinda odd, is that the pdf instructions for the
desulfator kit are dated as modified 25/03/2012, the same date as your post.

The desulfator instructions caution against using sophisticated/intelligent
battery chargers with the desulfator unit.

The desulfators I have are made up of just common components used for
creating the pulsing circuit.

I'm generally very doubtful of "miraculous recovery" products.. dead is dead
(although I do like a good Zombie movie).
Weak, old batteries need to be replaced. Neglect and abuse typically aren't
reversible, IMO.
That said, I do find it believable that a desulfation cycle can be useful as
part of regular service, maintenance and charging routines.
By desulfation cycle, I mean a separate action, not applied while the
charger is connected/active (although marketers claim desulfators can be
connected permanently.. car battery applications, for example).

I'm not familiar with the CTEK charger, but the 17V you're seeing could be
the full upper voltage level of the charger power supply, before it's
regulated down to 13.8V (or the appropriate output voltage), so the
suggestions regarding the likely damaged output devices seem reasonable.

Lead acid batteries are basically the same as they have been for
generations.. the capacity density has been improved and newer production
methods and materials have improved reliability.
Even though chargers now have uP control/monitoring, proper charging
practices are the same. The most practical approach is routine monitoring
and testing.

The most reliable option may be to have CTEK repair and recertify the
charger.

--
Cheers,
WB
..............


"joost" wrote in message
...
Hi,

In an attempt to restore a pair of sulphatated Trojan T105 batteries I
ordered a desulphator kit, soldered it together and hooked it up to
the batteries. After it had been pulsing for a week and a half, the
batteries needed to be recharged (the pulser is powered by the
batteries). I connected my nice CTEK 15 A charger WITH THE PULSER
STILL ATTACHED to the batteries. I'm afraid this was a mistake. In my
understanding, the batteries should absorb the peaks produced by the
pulser and not damage the charger. However, now it seems that my
charger is only outputting 17.0 volts (always) and heavily
overcharging any battery that I connect it to. The peaks from the
pulser might have been higher than I thought.

I opened the casing of the charger, but couldn't any component that
looked fried. Can anyone tell me where to start looking for the
defective component? It is quite a complicated microcontroller
controlled charger, but I still have some hope that there is a single
component that needs replacement for it to start functioning properly
again.

Many thanks,
Joost

On Mon, 26 Mar 2012 12:06:07 -0700 (PDT), joost
wrote:

The desulphator comes from Courtiestown:
http://www.courtiestown.co.uk/batter...ust%202011.pdf

Nice kit. Unless I'm reading the manual incorrectly, it suggests that
it is possible to run a battery charger and this desulfater in
parallel, at the same time.
DO NOT CONNECT THE DESULPHATOR TO THE BATTERY CHARGER
- CONNECT IT TO THE BATTERY & THEN CONNECT THE CHARGER.
MAKE SURE THE BATTERY CHARGER IS UNPLUGGED FROM THE
MAINS SUPPLY BEFORE CONNECTING/ DISCONNECTING.

In my never humble opinion, this is a bad idea, and asking for a
failure. I don't want to think about what high voltage pulses can do
to the attached electronics should the battery discharge and go to
high internal resistance.

The problem that is that the CTEK only stays in desulphation
mode for about 5 seconds.

If repeated at regular intervals, that's allegedly the desireable mode
of operation. Short bursts to break off the lead sulfate
encrustations, and long periods in between bursts for normal
operation.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

The instructions also state:

5. The desulphator should be used in conjunction with a simple trickle
battery charger. We would caution against using the desulphator in
conjunction with more modern intelligent chargers...

And.. recommendations to use a choke in series with (other) inverter type
chargers.

So it seems, the only types of chargers which are considered immune to
damage when used while desulfator pulsers are conected to a battery, are
transformer-rectifier types.

I'd done a considerable amount of reading about desulfator pulsers a few
years ago and found no mention that only the use of basic/dumb chargers as
being the recommended equipment.. although it seemed risky to have high
energy pulses applied to sophisticated chargers' output leads.

--
Cheers,
WB
..............


"Jeff Liebermann" wrote in message
...
On Mon, 26 Mar 2012 12:06:07 -0700 (PDT), joost
wrote:

The desulphator comes from Courtiestown:
http://www.courtiestown.co.uk/batter...ust%202011.pdf

Nice kit. Unless I'm reading the manual incorrectly, it suggests that
it is possible to run a battery charger and this desulfater in
parallel, at the same time.
DO NOT CONNECT THE DESULPHATOR TO THE BATTERY CHARGER
- CONNECT IT TO THE BATTERY & THEN CONNECT THE CHARGER.
MAKE SURE THE BATTERY CHARGER IS UNPLUGGED FROM THE
MAINS SUPPLY BEFORE CONNECTING/ DISCONNECTING.

In my never humble opinion, this is a bad idea, and asking for a
failure. I don't want to think about what high voltage pulses can do
to the attached electronics should the battery discharge and go to
high internal resistance.

The problem that is that the CTEK only stays in desulphation
mode for about 5 seconds.

If repeated at regular intervals, that's allegedly the desireable mode
of operation. Short bursts to break off the lead sulfate
encrustations, and long periods in between bursts for normal
operation.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 3/27/2012 10:48 PM, joost wrote:
It will be difficult to identify any IC. There are some, but all with
unreadable numbers. Thank you for your safety warnings. I wasn't
planning to do anything with the thing switched on. The probes of my
DMM are far to big to have any confidence in not touching the wrong
thing. As it is not worth here having it serviced by a professional, I
think the best shot for me is to take out the two FET's, test them and
replace if they are broken. It is low-cost and if it doesn't fix the
problem I will have to buy a new charger. However taking out the FETs
isn't easy either. It is a doublesided PCB and with only wick and a
sucker it seems impossible to get them off. I will try to cut the legs
and take them out on by one.

Output SCR's go with battery chargers having huge transformers.

Your smart charger probably is a straight forward converter with logic
built around the current and voltage sense to control it.
The good news is that it sounds like the charging path is working.
Bad news is that you probably broke something hooked to the output to sense
voltage and current. Follow the signal path from the + and - output
terminals back to some IC. That's probably what you broke...maybe...
There are lots of ways to do this function. Hard to know what to expect
knowing nothing about it.

The things labeled D are probably diodes.

You need an oscilloscope and an Isolation Transformer,
and someone who knows how to use both, to work on this thing.

Don't underestimate the potential of this thing to hurt you.
You don't have to get electrocuted. All you need to do is go
flying across the room and land on the corner of a desk.

Wear safety glasses. I scratched a cornea in a freak accident
when I came flying out the back of a TV set I was working on.
And I've still got scars where a slip of a probe caused a FET
to explode in my face. There's a lot of energy in a tiny space.
Be respectful.

It's difficult to say without some clues, but
IFF the two fets are on the input side of the transformer,
and the output is 17V, the fets are likely NOT your problem.

joost wrote:
Hi,

In an attempt to restore a pair of sulphatated Trojan T105 batteries I
ordered a desulphator kit, soldered it together and hooked it up to
the batteries. After it had been pulsing for a week and a half, the
batteries needed to be recharged (the pulser is powered by the
batteries). I connected my nice CTEK 15 A charger WITH THE PULSER
STILL ATTACHED to the batteries. I'm afraid this was a mistake. In my
understanding, the batteries should absorb the peaks produced by the
pulser and not damage the charger. However, now it seems that my
charger is only outputting 17.0 volts (always) and heavily
overcharging any battery that I connect it to. The peaks from the
pulser might have been higher than I thought.

I opened the casing of the charger, but couldn't any component that
looked fried. Can anyone tell me where to start looking for the
defective component? It is quite a complicated microcontroller
controlled charger, but I still have some hope that there is a single
component that needs replacement for it to start functioning properly
again.

Test for shorted power semiconductors or anything attached to a heatsink.

It's probably a Murphy's law type thing, but most power supplies fail with
no output, but battery charges like to magically fail at full voltage
output, just to destroy your batteries at the same time.

On Tue, 27 Mar 2012 16:36:27 -0400, "Wild_Bill"
wrote:
(...)

I found this article on sulfation problems and pulse chargers:
http://www.pulsetech.net/assets/Misc/Popular-Communications-August-2011_sm.pdf
from the Aug 2011 issue of Popular Communications magazine. Gordon
West and PulseTech claim that pulse charging works to prevent
sulfation. Nothing on how to deal with an already sulfated battery.
Includes some interesting photos of what the plates look like with
technologies.

More on the X-ray diffraction tests for battery sulfation:
Summary:
http://www.xtremecharge.com/files/support/Malinsky_Scientific_Summary.pdf
Full report is 50 MBytes:
http://xtremecharge.com/themes/XtremeCharge/img/Malinski_Full.pdf


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558