I wish to sit down for awhile to experiment with my BA Falcon using ascantool for some period of time. So that I don't run down the battery I've been advised to have charger hooked up to the car whilst working.

First of all, should I do this? Do I need any special type of charger to do this? I thought Lead-Acid chargers were trickle-charge only and would not supply much current.

Secondly, is there any preferred way to hook this up? Would it be the same method you use for jump-starting? ie Charger +ve to Bat +ve, Charger -ve to Chassis Earth (and not Battery -ve) ?


Lukeyson

As Elmer Fudd said "be VERY careful"!
There are two basic types of chargers, those that don't put out enough voltage to damage a batt (UNDER 14.8 vOLTS ) and those that put out over this voltage and are regulated by either their output current or voltage.

Putting a charger onto any vehicle with electronics is risky if the earth lead is left connected.

Chargers (most) are not filtered for spike voltages that constantly come through the 240V supply.

A solar panel will not have dangerous spikes but its output can go from 12 volts to over 18 volts if a no load situation exists, again risky.

Much safer to run off battery and recharge batt while having lunch or overnight, after disconnecting earth strap!!!!!!!!!!!

Many have got away with doing as you suggested but if your luck is like mine, well.

Chargers connect positive to positive etc, same as jumpers.

Sequence is;
Remove earth terminal (negative) from batt.
Place +ve, positive, red charger lead onto battery Positive terminal
Place black charger lead onto negative battery terminal
plug charger in and turn on.

When finished do in reverse order.

It's also a good idea to loosen the cell covers/screws/caps while charging.

REMENBER Hydrogen gas is given off when charging and this is highly explosive so no sparks, smokes and well ventilated.

When jumpering cars with elec components get proper surge absorbing leads or only allow one engine to run at a time. EG. Start with the engine of car with good batt turned off or charge flat batt, remove leads then start previously flat batt car.

Again, connect negative/black/+ve cables last and take off first.

Hope this helps!

See if you can borrow a deep cycle battery (or jsut buy one) ... might be easier and safer.

You could also play it safe by using a battery pack like from Supercheap etc with the cigarette socket, does the scan tool only get power from the OBDII connector or external alligator clips or cig socket.

Just from the OBDII connector.


Lukeyson

I am not familliar with the Scan Tool but unless it draws a fairly heavy current I would not worry about having a charger across your battery while using it. Put a charger on when you have done what you want to do with neg battery lead disconnected.

Alternative is to get a regulated charger or power supply that can be set to 13.8 - 14.0 volts. This will get around the spikes etc. I have used an adjustable 20 amp power supply on my EA and various other cars to do the same job. (When working on radio equipment etc).

Set output to just under 14 volts before connecting, switch off, connect to battery and switch on.

I have not had any failures or problems doing this but would not take any responsibility should you decide to try it.

Cheers, Chris

Get a good charger regulated and filtered.
Its the AC ripple that mainly damages the ecu, they cope with over/undervoltage fairly well.
Its a ford, Not a Mclaren!

I'd have to say, many of us just slap on a charger and leave it on. No changes at all!
In fact I have never heard anyone kill an ECU like this.
However Im sure it has been done.

Play it safe, remove the neg terminal... but this renders your tests useless then doesnt it?