Battery jump start pack vs immobiliser issue

[nomis 12]

I bought a powerful and decent quality little portable battery jump start pack to keep in the boot for times when my 1.9 GTI won't start.

Went out the other day having not driven the car for a while and it wouldn't start, so got the pack out and attached to the battery ready to jump start.

However, it wouldn't properly connect.

I think this is because of the immobiliser, as the battery was so dead the immobiliser light wasn't even flashing.

However, if I connect the car to another car with jump leads the immobiliser light starts flashing and I can then jump start it.

 

I know this pack works, as I have used it on the GTI when the battery wasn't so flat that the immobiliser had stopped working and also on my mum's old Mercedes, which is a 280SL, so has a bigger engine.

 

Anyone else encountered any similar issue or got any thoughts on how to get round this?

 

Thanks

 

Simon

 

[welshpug 1,621]

don't let the battery get so low!   many of the modern chargers and jump packs will not charge/provide jumping power if they don't sense a voltage above a certain threshold.

 

 

[Leslie green 80]

A flat battery is soon a dead battery , they really don't like being flat one bit ,if you get something like a ctek smart charger (other ones are available !) you can leave these connected as long as you like and they will monitor the battery but id guess you may need a new a new battery soon anyway .

[nomis 12]

There is some kind of drain on it, I think. The car regularly doesn't decent length journeys but also short ones regularly.

If the car isn't driven for over a fortnight, it suffers (worse in the cold).

Not managed to track it down. 

I'll redouble my efforts to get someone to do so.

Problem is that the car lives on the road, in London, so trickle charging isn't an option.

[nomis 12]

Thanks for the tips by the way.

So Welshpug, perhaps the immobiliser is a red herring and it is the battery being so low.

[welshpug 1,621]

that is what I would imagine yes.

[nomis 12]

Actually turns out that I did manage to get the pack to start the car from a totally flat battery.

 

I knew it was meant to be a powerful and decent quality one, (DBPower 660A Peak 18000mAh) but couldn't get a connection for it to try to start the car.

 

I emailed and asked them if they knew of the issue and they said they had never heard of that and offered to refund me my money in full and I should keep the pack, which seemed very generous.

 

After that and before using our other car to jump the GTI, I tried again last night. Same problem but then spotted that the instructions for the pack come in two parts and hidden away in one part is something saying if the light stays red press the button next to it for three seconds. Did that and lo and behold it went green, I jumped in the car, saw no immobiliser light flashing to switch off but the main light was on, so gave the key a turn and throttle a blip and the car turned straight over and started on that.

 

Took it for a good drive and will get some miles under its belt over Christmas, so hopefully that will charge up the battery (and I'll get onto finding that drain).

 

So, as it stands, if you are in the market for a portable car jump starter, I can recommend this one.

It's done the GTI and a 2.8 litre Mercedes and previously fully charged a phone via its USB with it only dropping down to 70%.

 

Now I just have to work out how to pay them for it again, as they've already issued the refund!

 

PS, reading instructions in detail can pay off.