Portable jump starter

[undyingking]

I was quite pleased to see that there exists such a thing as a portable jump starter, ie. a device that you plug in to the mains to charge it up, and you can then subsequently use it to jump start your car. This one at Maplin is an example.

Unfortunately, a bit of hunting around turns up reviews ranging fairly evenly from "it works, brilliant" to "it doesn't work, rubbish".

Anyone actually tried using one of these, and how does it compare with a normal trickle charger?

Comments

[zengineer.livejournal.com]

When I worked at Nissan we used them all the time for cars with flat batteries from electrical testing. The key things are current, it does take hundreds of amp to start a car, and lead size. This one seems a bit cheap but the specs look OK. Since it has a battery and was probably made in China then how it was maintained during shipping is critical. This may explain the varying reviews.
If you leave your car with a flat battery for long periods it degrades the cells so generally you need a new battery but this will at least start the car so you can drive to Halfords and buy one.

[undyingking.livejournal.com]

may explain the varying reviews

Mm, I was wondering about that -- makes sense.

Twenty quid seems almost too cheap not to give it a go, although the "what's the worst thing that could happen?" options are quite appreciable (especially as it's not my car).

[zengineer.livejournal.com]

Probably the worst that could happen is the car won't start so not too serious.

[undyingking.livejournal.com]

I was thinking of electric shock, explosion, blinding by hot acid... ;-)

[zengineer.livejournal.com]

12V DC so not too much danger of shock (keep your hands clear of the coil and the plugs if the engine is running). Sealed unit so not too much acid risk. Explosion is possible but very rare.

[wimble.livejournal.com]

I've had three over the years, two of which are defunct. The third's going.
The first one's dead because it's got very peculiar leads, and I've misplaced the charger.
The second no longer seems to hold a charge.
The third is still working.

I've also got a trickle charger, which is more reliable (assuming the problem is simply a discharged battery).

They have the advantage over trickle chargers in that they don't involve removing your existing battery from the car; they work reasonably instantly, without a need for a mains supply (at the point of your emergency); they might get you moving when the problem is the battery itself (rather than the lack of charge); they provide 12v DC for other accessories (I pump up my bike tyres with an electricly powered compressor, from the jump-starter).

The downside is that they're heavy buggers, because, in essence, you're carrying a spare battery. If you need it more than rarely, you've got a separate problem (which is the bit I got very wrong).

[undyingking.livejournal.com]

It is just a battery gone flat from unuse, I don't really have any other purpose for it at the moment. WOuld be good to not have to remove the battery -- I hate doing that -- although I hear that there are very clever trickle chargers now which don't need that either. Not to mention solar-powered ones, which I assume are entirely useless. What a wonderful world we live in.

[waistcoatmark.livejournal.com]

A solar-powered trickle-charger kept my battery going for 6 months longer than it should have done. The problem with modern car batteries (well the high-current ones you need for diesels at any rate) is that they wheese a bit for a week or two and then just die dead.

The last time it had struggled a bit to start (30 secs rather than 2) for a week. I then drove all the way down to Exeter during the day - so giving the alternator plenty of time to charge up the battery and when I tried starting the battery the next day it was dead. AA man checked all the electrics - it's just that batteries die v quickly and drastically these days

[undyingking.livejournal.com]

Mm, it'll be interesting to see if this flat period has degraded the battery, when I do get it back to life. Hadn't had any trouble with it before, but it wouldn't surprise me if it became rather more vulnerable.

[thefon.livejournal.com]

I have one, it works fine.
It cost a bit more (£50?) but it was a Sunday, only shop open within walking distance. It can pump tires, and also has a power socket you could plug other things into.

[undyingking.livejournal.com]

Mm, does sound like it could be a pretty handy thing to have around generally.

[caffeine-fairy.livejournal.com]

One of my neighbours has one and swears by it, but reckopns the cheap ones aren't worth it.

[undyingking.livejournal.com]

Mm, I noticed Black and Decker do a similar thing at about twice the price.

[rotwang.livejournal.com]

It does depend on the car and the charge required to start it. My diesel requires a lot of current - the couple of times I've had Green Flag out to start me their industrial strength portable starters weren't up to the job and they ended up attaching both them _and_ regular jump leads from their van engines to get mine started.

When I had to start mine from bibliogirl's car, I needed to run hers for about 25 mins charging mine before it would jump.

[undyingking.livejournal.com]

This is a petrol car, I think they're a bit less demanding. We shall see...