Can Anyone Help Me Please ?

[the_constructor]

Hi Everyone,

I wonder if anyone could offer me some advice please.

I have a mobility scooter and being a little suspicious that the charger was
not operating at full capacity, I decided to make myself a small Voltage and
Amp tester box.

My wiring diagram can be seen on the link below.

http://www.tuppencechange.co.uk/test/box_wiring.jpg

The problem that I have, not being a super electronics techy is this. When I
plug the output of the box into the charger socket of the mobility scooter,
I get a reading on the volt meter. Then, when I plug the charger into the
box, even before pluging thew charger into the mains power supply, I get an
even greater voltage reading. Only, when I plug the charger into the mains
power supply does the Amp meter register.

This box has a 30V and a 10A meter on it.

The mobility scooter charger is for 24V @ 5A

Should I have put a diode into the circuit before the output socket and if
so, what do you suggest.

What is the reason for the greater reading of the volt meter even though the
charger is not connected to the mains power supply.

Your help and encouragement would be most welcome.

Kindest regards,

James

 

[MisterE]

Should I have put a diode into the circuit before the output socket and if
so, what do you suggest.

no point

What is the reason for the greater reading of the volt meter even though
the charger is not connected to the mains power supply.

The output voltage will not be correct until a certain current is drawn.
Considering its specs, its likly that until you draw at least 0.1 amp that
the voltage will be to high, what voltage does it say when plugged into
both.

Your help and encouragement would be most welcome.

5A will be max the charger can output, not the amount it will actually
charge the batteries at. The current meter isn't likly to sell you anything
useful. Just charge the battery and disconnect it every now and then from
the charger and see if the voltage is increasing to the right amount.

 

[Franc Zabkar]

On Thu, 2 Oct 2008 22:11:52 +0100, "the_constructor"
<the_constructor@freeukisp.co.uk> put finger to keyboard and composed:

Hi Everyone,

I wonder if anyone could offer me some advice please.

I have a mobility scooter and being a little suspicious that the charger was
not operating at full capacity, I decided to make myself a small Voltage and
Amp tester box.

My wiring diagram can be seen on the link below.

http://www.tuppencechange.co.uk/test/box_wiring.jpg

The problem that I have, not being a super electronics techy is this. When I
plug the output of the box into the charger socket of the mobility scooter,
I get a reading on the volt meter.

What reading? Is it the battery voltage, ie 24-25V?

Then, when I plug the charger into the
box, even before pluging thew charger into the mains power supply, I get an
even greater voltage reading. Only, when I plug the charger into the mains
power supply does the Amp meter register.

Maybe you are reading the residual voltage of the capacitor on the
charger's output. This voltage could be around 28-29V.

This box has a 30V and a 10A meter on it.

The mobility scooter charger is for 24V @ 5A

Should I have put a diode into the circuit before the output socket and if
so, what do you suggest.

No, you haven't added anything that significantly alters the behaviour
of the charging system.

What is the reason for the greater reading of the volt meter even though the
charger is not connected to the mains power supply.

The charger may be retaining a voltage on its output capacitor from a
previous charging cycle. What was the reading?

Your help and encouragement would be most welcome.

Kindest regards,

James

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