Jump Leads vs Battery Jump Pack vs Charger

Soldato
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Hi - we have two cars. I have (embarrassingly) occasionally left the lights on my car, leading to a flat battery. The other car has not been started for over two months and didn't really have enough juice in the battery to start the other say.

I have a borrowed set of jump leads that have been used successfully to sort that issue as well as a borrowed charger that has topped up my car overnight. The two items need to be returned so I'm trying to work out the best thing to buy in case of a similar issue.

A charger is less than ideal as the vehicles are parked in a communal car park away from the house. I like the simplicity of a set of jump leads but there is a remote possibility both vehicles "could" have flat batteries at the same time. I like the idea of one of the lithium jump packs as a self contained device but there are so many to choose from. Vehicles are a 3l petrol and a 1.4l diesel.

What say motors? Cheers :)
 
A lot of modern cars don't like being jump started, we see quite a few in the main dealer which no longer start after attempting a jump start, normally it's a replacement ECU. We always disconnect the battery and charge the battery which is the safest way.
 
Charger if you don't need to go out instantly and can plan ahead to have it on the car 4-8 hours. Jump pack for that instant get up and go feeling, but you'd need to have a long drive planned to charge up the battery. If the battery is flatlining then leads are going to take a long time to do anything but I've had good success using a jump pack in a similar situation.

Had the same issue with communal parking, luckily we have a perimeter path around the edge of the building so I parked it on the grass right up against the building and dropped the power lead from an upstairs window locked both in the house and in the car so it couldn't be tampered with or tripped over. One neighbour offered jump leads when she saw the car charging (note in the window explaining why the car was parked there) but with no long drives planned I wanted the car on charge.
 
A charger is probably better, you could always bring the battery indoors and charge it up there? I used to do that before i built my garage and i couldn't get a car close enough to the house.

If you jump start a car it'll take a long time to charge it up enough as car alternators are pretty rubbish chargers, saying that i always have a set of jump leads in my boot just in case. I've used them on other peoples cars more than my own and for a few quid they're well worth having as a last resort.
 
I've got a small lithium jump pack and it has got myself and others out of trouble enough times to easily justify the cost of buying one. Plus it doubles as a portable power source for 5 and 12v devices. More convenient than cables as you are not dependent on someone else being there, their vehicle having enough power to start yours, and placement of vehicles in regards to attaching the cables.

Pair that with a battery charger/conditioner and you have all bases covered.
 
I have a lithium jump pack - seems to work and as above you can also use it to power small 12v and 5v devices if needed. They can usually also put out enough power to partially charge the car battery if you want to do it that way which then gives it enough power to start up the car itself. The only downside is remembering to keep it charged up every ~4 months or so.

EDIT: It is much better for the battery to charge it properly though if you are doing it anything like regularly.
 
Just to jump on this post and ask - if the battery is completely dead (so even unlocking has to be a manual thing) is the advice any different? I have been putting off starting my car as I had no time to drive it a reasonable distance, and now I have tried to start it... well... it's quite clearly entirely flat.

Do the small lithium ones cover this to? I am amazed that they've all become so small these days (the last one I had was a hefty thing - it worked though!)
 
Yes they do. I had the same with my car this weekend, totally flat battery and couldn't get in. Key wouldn't work in the door lock either (it's keyless usually) without an injection and soak in wd40. Anyway battery measured 2V on multi meter while trying to run interior lights as the door was open. Lithium pack on didn't work starting the car in normal mode but did in the full power on boost (I think battery too low to trigger the pack when starter tried, on boost I think it just switches on). Car started and ran fine apart from I had to reset the steering lock sensors before it was driveable. It's a 2010 mazda6 2.2d with 220k on the clock so not in its first spring of youth. Pack was https://www.halfords.com/motoring/b...ters/gb40-1000a-noco-jump-starter-721898.html
 
totally flat battery and couldn't get in. Key wouldn't work in the door lock either (it's keyless usually) without an injection and soak in wd40. l

I have always felt that cars should be fitted with one of these externally accessible (Behind flap in bumper or whatever) so cars with flat batteries can be powered up so doors can be opened electronically and subsequently safely started.

Also for making positive connections with BSU's when carrying out work such as software updates rather than relying on not terribly reliable battery clips. (which are not much good for either role)

It really wouldn't cost much to implement and would make life a great deal simpler in the event of problems
 
The lithium booster packs are surprisingly good. The AA were testing one out at work on various vehicles when they first came out, and on a totally flat 2.0 Transit van, it would make a reasonable attempt to crank it. It wasn't enough to start it, but we were surprised it even managed to crank it over. On something just needing a bit help, they worked well.

If the cars are parked outside, it might be worth considering a small solar panel to keep the one that doesn't get used much topped up.
 
Yes they do. I had the same with my car this weekend, totally flat battery and couldn't get in. Key wouldn't work in the door lock either (it's keyless usually) without an injection and soak in wd40. Anyway battery measured 2V on multi meter while trying to run interior lights as the door was open. Lithium pack on didn't work starting the car in normal mode but did in the full power on boost (I think battery too low to trigger the pack when starter tried, on boost I think it just switches on). Car started and ran fine apart from I had to reset the steering lock sensors before it was driveable. It's a 2010 mazda6 2.2d with 220k on the clock so not in its first spring of youth. Pack was https://www.halfords.com/motoring/b...ters/gb40-1000a-noco-jump-starter-721898.html

Excellent thanks - have ordered one and hopefully all will go well.
 
A lot of modern cars don't like being jump started, we see quite a few in the main dealer which no longer start after attempting a jump start, normally it's a replacement ECU. We always disconnect the battery and charge the battery which is the safest way.

Would one of those Lithium jump packs risk damaging the ECU or would they be safe like using a Battery charger?
 
Would one of those Lithium jump packs risk damaging the ECU or would they be safe like using a Battery charger?

The only ECU failures I've seen after attempted jump starts, have been down to idiots connecting jump leads the wrong way around.
Battery gases is only one reason the final connection should be made to the body/engine rather than the battery terminal. The other reason is if you do have the positive lead on the wrong place (aka the negative terminal), you'll just short out the jump leads (lots of sparks), rather than put reverse voltage through the entire system.
However with modern vehicles with dedicated jump start points, you no longer have that protection option.
 
A lot of modern cars don't like being jump-started, we see quite a few in the main dealer which no longer start after attempting a jump start, normally it's a replacement ECU. We always disconnect the battery and charge the battery which is the safest way.
Same with modern trucks, you'll often see them with stickers on the back of the cab saying "do not jump start" - especially Iveco's for some reason...

On the rare occasion these days that the truck won't start due to a battery problem Scania (or whoever) will come out and change the batteries rather than jump start it.
 
I have one of the Sealey Electrostart 800 packs. Basically a bunch of capacitors that your flat car battery (providing it’s hold 5 Volts or better) energises for 2-3 minutes and then makes this power available to turn the engine over for 20-30 seconds.

If the vehicle’s battery is dead flat, you can charge the pack from the 12V accessory socket in another car or from a USB charger.

Have started a number of 2.2 and 3 litre diesel vans with it in the U.K. and a particularly surprised and impressed firewood delivery man’s ancient Renault truck with it over here.
 
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