--- In randrdesulfatorforum@yahoogroups.com, Rick
<fun_4_me_now20012000@...> wrote:
>
> Hello spartakplutonium
>  
>  
> If you feel you must, you should use a constant current charger of
about 300ma. A constant voltage charger is not a good idea as it will
put out it's max current until the battery voltage rises, and if it
doesn't rise (like if you have a shorted cell), you will bubble your
battery to death and maybe start a fire or create an explosion.
>  
> As for the 10.5v battery, it sounds like you have a shorted cell.
The pulses will bypass a shorted cell and therefore never do it any
good. That said, if you have a constant current circuit (like using
an lm317 configured to regulate current), it may be worth a shot.
>  
> RIck.
>
Thankyou so much. You are quite right. On investigation one cell has
a short circuit.

I didn't think of configuring the LM350T as a precision current
regulator. Clearly a mark 2 on the way. Is there any way of using the
PIC/PCB as it stands to turn the charger on and off?

On the bright side your board arrived from Courtiestown quite quickly
for New Zealand and worked first time. I was very happy with the PCB
and components - a design to be proud of.

I've had the battery connected for a day now and I'm a bit confused
although that's not unusual. Notwithstanding the bridged cell the
gravity of the other cells has fallen markedly and the open circuit
voltage across the battery has fallen to 10.25v. Ambient temperature
is a steady 18C.

Maybe I'm being daft about the way I've got this rigged. I've put a
picture of the system being tested on this board called 'Graham's' in
it you can see that I've attached the 13.8 volt lines directly to the
battery connectors which are clamped to the fat cables connected to
the pulser. Is this a mistake?

Anyway Rick thanks for your time and all the best.

Graham

> --------------------------------------------------------------------
--------------------
>
> --- On Tue, 10/28/08, spartakplutonium <spartakplutonium@...> wrote:
>
>
> From: spartakplutonium <spartakplutonium@...>
> Subject: [randrdesulfatorforum] Noob Knob Just About to Assemble a
Courtiestown PIC Pulser
> To: randrdesulfatorforum@yahoogroups.com
> Date: Tuesday, October 28, 2008, 9:33 AM
>
>
>
>
>
>
> Hello and thankyou to this group.
>
> After nearly a year now of lurking around desulfator boards and
> postings I am about to receive (should God and the New Zealand
Postal
> service will it) a Coutiestown PIC desulfator.
>
> Coutiestown have already e-mailed me with the schematic and build
> notes but I would like to ask if anyone has any top tips that
aren't
> on the release notes.
>
> The schematic has no version number so I'm not too sure what I'm
> actually getting. The build notes do say that there is a pot that
> should be trimmed at build time.
>
> I have just finished making a trickle charger to go with the pulser
> which has a variable regulated output between about 10 and 16
volts.
> What kind of voltage should I start at please?
>
> My first candidate is an automotive battery originally from a great
> big BMW. A regular battery charger never thinks it's charged and as
> soon as the charger is disconnected the battery's voltage quickly
> drops to 10.5 volts then slowly to nothing. Does this sound like
> a 'good' candidate?
>
> Anyhow, at the risk of confiming my credentials as a nerdy
knobhead,
> I'm really excited about this project and would truly appreciate
any
> words of wisdom.
>
> All the Best Everyone
>