Jump starting a Bongo

[mikeonb4c]

Guys thanks for all your helo.
In the end I have charged the battery as per normal, refitted it and away first time.

I can only presume my car didn't have enough 'ummph' to start the Bongo.

First lesson learnt!

Could have been faulty jump leads, but maybe the flat battery was taking all the juice

[ELZE]

Bongo doors are notorious for not shutting firmly and often need a good 'clunk' My son left mine only latched halfway and battery went totally flat due to interior lights. I was away working at the time so it was not noticed for a week. On my return I purchased a new battery thinking the old was would be dead. Charged the old battery and it seems to be fine £70 I did not need to spend?

Still a spare is not a bad thing...is it?

[windywatson]

If you are using what I think you are, because you said booster cable. Then I can answer your question. The booster cables that you often see advertised that plug into each vehicles cigerate socket are limited to the amount of current that can be passed. And also as the lighter socket on these vehicles is not permanently/directly wired across the battery and only live when the ignition is on, you have to make sure the ignition is on in order to pass charge to the vehicle battery.
The only quick way to jump start a vehicle is with a good set of jump leads directly connected battery to battery. Otherwise with a booster cable on a totaly flat battery your on with a long wait to get enough charge to start a engine. The clue is in the name Booster Cable. They are really designed to give a lowish battery a boost no really meant to recover a flt battery in a short time.

Cheers

[Diplomat]

I assume you have got the engine running on the car??

My preference is to run the donor vehicle for a while to restore some charge to the recipient battery, then switch it off immediately before starting the poorly vehicle but leaving the jump leads in situ to give the benefit of a good battery in parallel.

I used to keep the donor engine running during the restart attempt but went off that idea when I thought about the poor old alternator trying to match the starting current. In those days I was jump starting much smaller cars, not 2.5 litre diesels.


Frank

[briwy]

I assume you have got the engine running on the car??

My preference is to run the donor vehicle for a while to restore some charge to the recipient battery, then switch it off immediately before starting the poorly vehicle but leaving the jump leads in situ to give the benefit of a good battery in parallel.

I used to keep the donor engine running during the restart attempt but went off that idea when I thought about the poor old alternator trying to match the starting current. In those days I was jump starting much smaller cars, not 2.5 litre diesels.


Frank

Yes but the current to start the vehicle is coming from the donor vehicle's battery, not it's alternator. The alternator will just keep running at it's rated output to top the battery so shouldn't come to any harm. If you don't keep the engine running there is a possibility that you could flatten to donor vehicle battery as well then you're in deep doo doo

[mikeonb4c]

I assume you have got the engine running on the car??

My preference is to run the donor vehicle for a while to restore some charge to the recipient battery, then switch it off immediately before starting the poorly vehicle but leaving the jump leads in situ to give the benefit of a good battery in parallel.

I used to keep the donor engine running during the restart attempt but went off that idea when I thought about the poor old alternator trying to match the starting current. In those days I was jump starting much smaller cars, not 2.5 litre diesels.


Frank

Yes but the current to start the vehicle is coming from the donor vehicle's battery, not it's alternator. The alternator will just keep running at it's rated output to top the battery so shouldn't come to any harm. If you don't keep the engine running there is a possibility that you could flatten to donor vehicle battery as well then you're in deep doo doo

I'd have thought it would pull power from whatever is in the circuit and able to deliver it.

[Simon Jones]

You should definitely leave the donor vehicle running:

http://www.theaa.com/motoring_advice/br ... leads.html

[Diplomat]

You should definitely leave the donor vehicle running:

http://www.theaa.com/motoring_advice/br ... leads.html

I used to until I thought about it.

If there is a danger that the donor battery won't subsequently start the donor car, it is probably not a good battery and therefore its internal resistance might not prevent the donor alternator from looking at a very high current in the starting circuit. When starting the donor car the alternator is not functioning but it is once the engine is running and having to replenish a battery which is supplying normal loads such as lighting, fans, wipers etc. but it is not expecting a drain of hundreds of amps, as created by starting another car.

If I know I have a good donor battery, I will start another car with the engine off. If I suspect that my donor battery is borderline I will give both a good charge before trying.

What I sometimes do, on the driveway, is take an extra battery from indoors and parallel it with the donor using more jump leads. Use the best set of leads, with the most aggressive clips, between the two vehicles.

I can understand the AA not wanting to come out to two flat batteries, one of whom is not a member, but should they recommend a procedure that might damage a donor alternator if the donor battery isn't really up to the task and the recipient requires a lot of cranking?

Starting a small car from a Bongo which has a good battery and has just been running is one thing. Starting a cold Bongo from a small car can be something else.

Frank

[scanner]

All advice I have ever read says keep the engine running.

[Gasy]

Of course you keep the engine running
As said above you don't won't to end up with 2 cars with flat battery's do you

[Diplomat]

Of course you keep the engine running
As said above you don't won't to end up with 2 cars with flat battery's do you

All of you and the AA might keep the engine running.

I don't, anymore. Not since I've thought about putting that load, even for a short time, on the alternator diodes. You are asking them to supply what the battery demands plus any shortfall in the starter current that an iffy battery is incapable of fully supplying.

Think about it another way: If it isn't going to be man enough to start another vehicle, should you be expecting it to start its own vehicle reliably?

In the case of something heavy like a Bongo needing starting after its good battery has accidentally gone flat, my procedure would be to feed it from a running car for 5 or 10 minutes, give it some glow plug applications while still being charged and then disconnect and try a self start. If nothing happens, it probably needs a new battery anyway. I would not risk damaging the alternator on my own small car by presenting it with Bongo cranking current except in dire emergency.

That's my policy, even if it's not the AA's and I'm sticking with it. I don't believe that the AA procedure is risk free. Burnt out diodes have a habit of not being noticed for a while, unless you smell them at the time.

Where's Geoff?


Frank

[mikeonb4c]

I'm no techie but I fancy I can see Franks point. On the other hand I'd hate to end up stranded because I helped another motorist and flattened my battery. I think I might decline to service a car with a flat one if I saw it's was bigger than mine. If it's smaller, I think I'd charge it from mine for a few mins before attempting to start it.

[David Edwards]

Something was running my battery down and I cant find what it is, so I have a large plastic crate in the boot with a spare charged battery in it, just in case, of course since I have done this, it has not gone flat one me. typical eh but at least I know it's there if I need it.

[g8dhe]

Keeping out of the discussion

There are two many variables to say which procedure is best!

My own choice on the few occasions of having to jump start a vehicle is simply to let the flat battery charge for as long as possible 10-20 minutes, then to keep the donor engine running on the principle that the extra resistance between the two sets of batteries from the jump leads means that the surge will be handled by the "flat" battery, now with a bit of charge in it, and only the much reduced starter turning over current is being drawn from the pair of batteries and the alternator.