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Tiny LIPO based car engine starter - too good to be true?
Pete W.:
Hi there, Andrew and Steve,
A couple of decades or so ago, I was a member of a development team working on a system, some of whose units would need to be battery powered. We'd assumed NiCd rechargeables because that was common in the customer's inventory already.
One day we had a visit from a sales rep for a branch of a well-known multinational company - he'd come to try to convert us from NiCd to Lithium (I don't remember which lithium) batteries. He did a very skilful delivery of his sales pitch and it all sounded quite modern and marvellous. But then I think there might have been a mention of a visit to his firm's premises for some demonstrations. At this, his demeanour changed, his face fell and he said that would not be possible - their laboratory had burned down!!
But he made a quick recovery - his face brightened and he said 'Well, I did tell you Lithium's a high energy system'!!!!!!!!!!!!!!!!!!!!! :lol: :lol: :lol:
BaronJ:
Just sticking in my 2 penny worth here because I've never had one of those booster packs.
However my theory goes like this, You connect the booster pack across the existing car battery, and the first thing that happens is the fully charged booster pack starts charging the relatively flat car battery and at a fairly high current. This causes the car battery to charge up. After a period of time there is now sufficient charge in the car battery plus whatever is left in the booster pack. This is probably enough to start a car engine.
If you have ever noticed even with a battery so discharged that it can barely turn the engine over, the car can usually be push started.
dsquire:
--- Quote from: Baron on January 06, 2015, 04:41:44 PM ---Just sticking in my 2 penny worth here because I've never had one of those booster packs.
However my theory goes like this, You connect the booster pack across the existing car battery, and the first thing that happens is the fully charged booster pack starts charging the relatively flat car battery and at a fairly high current. This causes the car battery to charge up. After a period of time there is now sufficient charge in the car battery plus whatever is left in the booster pack. This is probably enough to start a car engine.
If you have ever noticed even with a battery so discharged that it can barely turn the engine over, the car can usually be push started.
--- End quote ---
This only works for cars and trucks with standard transmisions. :D
Cheers :beer:
Don
vtsteam:
Baron, that would be do-able -- maybe it works that way. You'd need a fairly high voltage to push say 80-100 amps into the other battery like a fast charger does. Four lipo cells would produce about 16 volts. I don't know if that is enough to do it. The more cells at 16,800 mah the higher the cost. But maybe it works that way.
You couldn't just clip and go, you'd need to wait a few minutes to get enough charge. Maybe that's how they do it...
Pete.:
Well I'm one of the responders in the welding forum thread AND I have one of these packs, so let me pass along my experiences.
Firstly, my pack is not Li-po - it's Li-ion. The one discussed is I believe a Li-po, and it's less than half the cost of mine (actually looks to be a Chinese rip-off since it uses a similar case, leads, clips and charging adapters).
I got mine because someone lent me theirs and I was impressed with it. We have a diesel-engined skid-steer loader on site and one day it wouldn't start, a dodgy relay connector was stopping it from injecting diesel so the guys did what comes naturally and cranked it until the battery was flat. The fitter who came the next day carried one of these in his van and at first I scoffed at it but he said 'try it and see' so I clipped it to the starter hit the key straight away and it cranked quite smartly and fired right up.
I realised that this would be a handy thing to own so I got the wife to buy me one for Christmas. Right out of the box with no charging done I used it to charge my phone from half-flat and my tablet from half-flat and the battery indicator was still above half (about 3 hours charging done). I then gave it a full charge.
When I went back to work in the new year I took it because I knew one of the 5-ton diggers had a tired battery and sure enough it was too flat to start. I clipped this onto the battery gave it two heats on the plugs and it too fired right up. No waiting involved.
So what do I think of it? Let's see.
Does it charge stuff like it says it does? Yes, it does do that. I think the figures quoted are 'up to' and definitely best-case but if you're travelling and you need a boost for your phone or to power your laptop for a hour then it'll do that with ease.
Does it crank engines like it says? Yes it does. Both times I have tried it I've hooked it to a flat, but not totally dead battery and both times it bolstered that battery enough for an instant start. The fitted had claimed that he had disconnected the battery from his transit and started it 3 times in a row, though I did notice that the booster wires on his showed signs of having been heated.
Do I believe the performance specs? No, I don't see how you can put 400 amps down those wires, but that doesn't mean it doesn't work as a booster-pack - I've used it and it surely does.
Am I satisfied? Damn right! Would have been even more so if I had known you can get them for less half the cost I paid for mine (though the quality is as yet un-proven) but even at £150 I'm happy with it. I had four tipper lorries booked and a flat 5-ton digger to load them with. It paid for itself on the first working day of this year and with interest.
Would I recommend it to others - yep I would and I have. I think that so long as you understand what it's intended for - boosting a flagging battery on a family runaround, not cold-cranking a Scammell truck - you'll not be disappointed. For me the most endearing feature is the tiny size of it. 6"x3"x1" is tiny for what it can do.
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