car booster help please

[happyhero]

Hi I was thinking of getting one of those boosters that you can plug into the mains and charge up and then start your car if the battery is flat, usually comes with a car tyre pump and torch.

But how do I know what rating etc I need. I have an old Mitsubishi Shogun 3 liter petrol. We have another vehicle and on the odd occasion (I know its not ideal) we leave it unused for a week plus and on a couple of occasions it has resulted in it being flat.

I know you need a more powerful booster the bigger the engine you want to start, but don't really know what I need. I don't want to pay the earth but I don't want to buy some incapable rubbish, so any guidance appreciated.

Any help appreciated.

 

[^neo^]

As long as you remember they are just "booster" packs, Clarke do some pretty resonable ones. Most of the time the battery will just require a little bit of extra juice to start the car, if the battery is dead then you have next to no chance of starting with a booster pack.

Have a look on Machine Mart website

 

[happyhero]

Cheers ^neo^, what I was worried about is that I have heard many times, people say, if you get a cheap one it will start a small car but wont be man enough to start something bigger like my 3 liter Shogun

 

[^neo^]

One ive seen that clarke do is supposed to be 700 boost with 400 amp cranking, so should be more than enough for what you want. About £35 i think

 

[Belle427]

id agree with all that,if the battery is flat as a pancake you dont stand a chance of starting it with the cheaper versions

 

[davieboy]

clarke booster pack starts my jones iron fairey 6 cyl diesel crane no probs. about 6 litre ford diesel. get no lights at all on dash, connect booster pack and away she goes. quite surprising

 

[chapmanbilly]

They must be very good cos you have to get a diesel engine turning over to at least 100 rpm before you have any chance of getting it to fire.
Might buy one of those myself if they're that good.

 

[happyhero]

Cheers for all that info guys, I am tempted with the Clarke booster but one thought, obviously you may not need to use these things too often if you are lucky, so what does that do to it, ie I assume they have an internal battery that gets charged up when you plug it into the mains.

Well if you charge it up and use it once and then end up leaving it in the cupboard for 8 months etc, doesn't that ruin the internal battery, ie if you kept a car battery for ages and didn't use it, isn't it bad for it? Heard something about storing batteries for ages unused is not good but not really sure about it.

 

[^neo^]

If its the one with the light and/or compressor then i guess it would be an idea to let it run flat every 3 months or so and recharge it.

Never really thought of that before tbh

 

[Coniferman]

I have a cheap one from b+q. The manual says something like it will keep for up to 3 months in a car boot and then just connect it up to keep it charged.(either via cig. lighter or mains) IMHO it is just best to keep it fully charged as much as possible rather than discharging. Mine has a lead acid battery but is slightly more deep-cycle resilient than a car battery.

They really do work. Turned out my car had a duff alternator but it got me going every time and even after jump starting a small car a few times it only needed a few minutes to fully charge itself up again.

One thing I happen to like about the model I got (which seems to vary to the manual slightly) is that there is an on/off switch for the jump leads. I guess this means there is less likelihood of causing sparks and potentially exploding the battery as it is connected. This means you can connect both clamps direct to the battery without having to bother with finding a negative ground. (This is just my supposition - at your risk) Maybe they all have a switch - just that the manual didn't seem to know about it.