jump starter battery

These things are IMO a waste of money unless used on a regular basis and recharged. Scrap it and rely on a long pair of jump leads and a friendly passing motorist.

Yes but I suspect you don't live in London on a narrow road with Victorian terraces and bugger all room for a jump start without blocking traffic :)

And if maintained as you suggest I find them sometimes useful as a portable work light or standby in case of power cuts (so long as you use LEDs and not the silly festoon lamps often fitted to them).

Lead acid batteries don't take kindly to being let go flat. And left like that. They need to be charged on a regular basis - say every couple of months or so. And they hold their charge better than any other type of battery. ;-)

Buying in bulk. It's the same as you'll find with power tools. A new battery can cost as much as the entire thing.

Carry a set of jump leads?

My jump start pack has a tyre compressor built in. So does get used.

Maplin sell several different versions. If you paid less than 50 quid for yours it's unlikely to be powerful enough to start a car whose battery is flat, anyway. BTDTGTTS!

I've now got a heavy duty jobbie - which cost me about £75 on special offer. It has really heavy cables which are only live when a large rotary switch is turned. It also has a built-in compressor for inflating tyres. I *have* used that in anger to start my wife's Puma - and it worked a treat. Haven't needed to use it on my 2.4 litre Volvo diesel though - that'll be the real test!

So, get yourself a decent one - and keep it charged.

En el artículo , Chris Whelan escribió:

They do if some dimbulb (i.e. yours truly) drives and parks up, turns the lights full on instead of full off and doesn't hear the (too quiet) alarm, then returns some hours later and wonders why the plipper isn't working to unlock the car.

BTDTGTTSTMT :)

Unless used in very extreme situations, modern cars don't get flat batteries. They also generally last 10 years or so.

Put the money towards AA membership would be my advice.

Chris

Or you have a 7yr old car and go away for a frosty month with the car outside.

My cover is via my bank account (Nationwide). The recovery vehicle was here within 3 mins of my call! Is that a record?

PS what's with the F/up?

Personally I would forget lead acid batteries and get something like this:

I have a couple of them. One had a switch failure after a couple of months with trivial use, but Amazon replaced it without any dispute.

I use them to power CCTV but have used them as jump starters, lights, and for powering or charging USB devices (phones and satnavs). Much lighter and more compact than yours, fits in a (large) glovebox.

Correction mine is this one

One came with an air pump, but that is pretty rubbish.

Actually, very old cars are likely to start after being unused more than newer ones - as they don't have the same quiescent load on the battery. Many modern cars will flatten their battery in about 3 weeks. Immobilisers, remote locking, ICE etc all take current even with the car stopped.

Can you guarantee that will hold a charge unused for longer than a lead acid?

I'd say it almost certainly won't.

The original batteries are low quality and really cheap and nasty. If you are not likely to look after it then just get RAC cover. Otherwise buy a decent battery (yuasa) and fit it to your unit and give it a charge every 6 weeks or so. If you just buy a complete cheap unit it will just have another cheap short life battery and you will go back to square one. I found that even regularly charged and used the original in a clarke jump pack will only give a year or so before being too weak to help when needed. I cut the case about and added a fiesta size battery, now that gives you some serious life and starting capacity, but does make the unit pretty heavy.

They are *claiming* need to recharge at ~ 6 months. Old lead acid batteries don't last that long. As it happens, the way I use them they get recharged at least monthly. They are a fraction of the size and weight of lead acid. Granted there is some fire risk, but you don't get an acid spill if you drop one. Plus, they make a good emergency light if you get stuck on a wet night on a hard shoulder with no electrics. A couple of times I have been able to recharge a flat mobile phone away from mains without having to leave a vehicle engine running.

Not saying they are for everyone, but *I* find them handy.

If by old you mean knackered, I'd agree. But lead acid in good condition has the lowest self discharge rate of any re-chargeable battery.

That makes sense with any battery.

Yes. But a lot more expensive.

You don't need a battery anything like that size or cost just to re-charge a mobile phone. Nor should you need to run the engine in your car either to do this - a mobile phone charger only takes about an amp.

They are certainly interesting. Love to see how many cycles of starting a car they would do before failing. I'd guess less than the fingers on one hand.

I think you have it there. Caning any small battery will shorten its life dramatically. Not sure a posh make like Yuasa would stand it either for more than a few cycles. Far better to use a battery designed for the job, but of course they are bigger and heavier.

My jump start pack came from Lidl when they were still new in the UK. Cost about half Halford price for the same sort of thing. And it still works for pumping up tyres or anything where you want a portable 12v supply. But won't deliver as much current as when new. I'm amazed it's lasted this long. ;-)

They claim to be able to supply 600 amps for 3 seconds - but the cables feeding the large croc clips don't look to me like they'd handle 600 amps.

they might, for 3 seconds.

I assume these are LI-ION packs - well they are very very good at delivering high peak currents.

Supercaps?

Quite, my 14 plate puts itself to sleep after about ten minutes, wether you want it to or not. That means shutting down the ICE, shutting down the "permanent" 12 V to the interior lights...