9 replies to this topic

[IronmanG]

This is about a jcb we have at work where the battery keeps going flat. It literally goes flat within minutes of being run and needs to be boosted.
I'm just looking for a couple of ideas.
I put my accumate on it without disconnecting the battery. 48 hours later it was still charging. So I disconnected the battery and it was charged in 20 minutes.
So the drain is constant and more than the charger puts out. That must be something quite heavy draw to do that. Even a short
I'm thinking just put a kill switch on it. On the positive side so that if there is a short somewhere it will stop that until it needs to be run

[Ethel]

Perhaps it was nearly charged. Disconnect the battery, if it still goes flat it can only be an internal fault. If it is on the digger it sounds bad enough to need finding & fixing.

[IronmanG]

No I connected the battery back up, reconnected the accurate and it wouldn't finish charging again. Definitely a big drain somewhere

[bpirie1000]

Before you get stuck into doing things as above.. check your engine earth strap. Add one ( or two) and make sure you have a really good connection.

More earthstraps the better I would say.. not going to do it any harm.

Under engine steady near to master cylinders in right hand drive cars...
Also added one to the Front panel mount. Onto the bell housing bolts.

Worth a try before major headaches start....

Would also check the positive from the boot to the solenoid... seen these melt to exhausts and cause issues you describe. .

[IronmanG]

Before you get stuck into doing things as above.. check your engine earth strap. Add one ( or two) and make sure you have a really good connection.

More earthstraps the better I would say.. not going to do it any harm.

Under engine steady near to master cylinders in right hand drive cars...
Also added one to the Front panel mount. Onto the bell housing bolts.

Worth a try before major headaches start....

Would also check the positive from the boot to the solenoid... seen these melt to exhausts and cause issues you describe. .

It's on the JCB at work but same principles apply. I tested the earth and its got 0 resistance

[68+86auto]

We can't really help remotely other than throwing guesses at you as to what the load might be. Measure the voltage drop across all the fuses to try and find the load. I would put a clamp meter on a battery lead.

Edited by 68+86auto, 03 August 2024 - 09:55 PM.

[IronmanG]

We can't really help remotely other than throwing guesses at you as to what the load might be. Measure the voltage drop across all the fuses to try and find the load. I would put a clamp meter on a battery lead.

Yep will do. There is a box on the positive post with about 5 wires coming off it. I will test each of those individually

[PACINO]

Hello. I've spent half my life having problems starting the engine, especially on cold days. At first when I bought this car (1992) it was horrible. Shortly after buying a new battery, it was losing power and I finally had to take it to be recharged. I knew very little about classic Minis and I didn't understand many things. Over the years I learned that it is very important to make a good ground connection of the negative cable on the metal sheet of the boot. Also that the ground is optimal in the starter solenoid that is screwed into the sheet metal in front of the clutch cover in the engine compartment. I changed the dynamo for an alternator. I improved the distributor, coil, spark plug wires. And now finally, I have put in the largest battery that fits in that hole. Portuguese Volta battery.
-12 V 90Ah 820A EN
-315x175x175 mm
Very strong battery with two years warranty.

[coopertaz]

if there is a draw that large the battery lead will spark when attached, connect a digital meter in line with the battery lead, not parallel and this should read 0amps with all off. if above this repaet on feeds from live post to find the draw. meters are usually fused at 10A so if greater will just blow internal fuse

[Rorf]

Take it to an auto electrician before you set fire to the car