Li-ion to jump start a car?

[thedoc007]

Thanks. Don't you think by now that Li-ion could, perhaps should, be an option for the primary start? AND an why not have an option for a backup jumper battery built-in? Lots of expensive stuff on cars these days that are unnecessary, that people pay for, especially in the premium models; leather interior, electric windows & locks, window tinting, superchargers, tires that will re-inflate if pressure too low, televisions, closed circuit video systems with infrared... the list goes on... how many here with pickup trucks have hand-warmers built-in in to their steering wheel? So what is even $500 extra when you're spending $30K-$80K on a vehicle? This is nonsense, unless there are more reasons than cost.

WITL covered it well, there are definitely other reasons besides cost. I also think the money would be better spent on managing the primary battery. Take the $500 you want to spend on a secondary jumper pack, and use it to build in a cutoff, so your main battery doesn't get drained in the first place. Many cars already have this to some extent, but it could be improved, and would offer a much greater practical benefit.

 

[CTR]

Re: Battery Jumpstarters

Battery question, has anyone used these things to start a car?

http://www.amazon.com/dp/B00KCD05Y6/?tag=cpf0b6-20

Just curious how they work compared to the SLA packs out there. May be something to throw in my motorcycle saddlebag.

I bought a more compact version of the one in your link about 6-8 months ago and tested it on my father's VW golf which has been sat at home without a battery for about a year. First time I connected it up she fired up easily. All electrics worked and I only had the jump starter connected, no battery. It's fantastic if you ask me. I bought it for my wife's honda jazz as she does a lot of short journeys which kills the battery.

I have used SLA versions before, but they are far more heavy and bulky. The one I have easily fits in my coat pocket and hardly weights anything.

 

[Gauss163]

Take the $500 you want to spend on a secondary jumper pack, and use it to build in a cutoff, so your main battery doesn't get drained in the first place.

Li-ion jumper packs are much cheaper than $500, e.g. $45 Buy It Now on eBay, and cheaper at auction (I won one for $13). Compare to $180 at AutoZone. They provide much more utility than alternative solutions since they can charge laptops, phones, etc and are small and light enough to carry around in a jacket pocket.

 

[WalkIntoTheLight]

Li-ion jumper packs are much cheaper than $500, e.g. $45 Buy It Now on eBay, and cheaper at auction (I won one for $13). Compare to $180 at AutoZone. They provide much more utility than alternative solutions since they can charge laptops, phones, etc and are small and light enough to carry around in a jacket pocket.

The $500 was not for an external jumper pack, it was what someone wanted to spend on an integrated jumper built into their car at the factory. Yeah, it probably would cost $500, given the ridiculous cost of other options like floor mats, etc. In any case, it's a bad idea, because the lithium-ion battery in it would probably fail before the main lead-acid battery failed.

 

[Gauss163]

The $500 was not for an external jumper pack, it was what someone wanted to spend on an integrated jumper built into their car at the factory.

Right. My point was to emphasize that it can be done much cheaper if you DIY.

 

[tandem]

Li-ion jumper packs are much cheaper than $500, e.g. $45 Buy It Now on eBay, and cheaper at auction (I won one for $13). Compare to $180 at AutoZone. They provide much more utility than alternative solutions since they can charge laptops, phones, etc and are small and light enough to carry around in a jacket pocket.

Do those eBay packs meet all mandatory safety standards applicable in your jurisdiction? Are they built with new cells? Does the charging circuit implement a proper CC/CV algorithm? Does it terminate at full charge or maintain a trickle charge against all wisdom, as many eBay chargers do? Does the pack incorporate protections against a dead short? Thermal monitoring? Under/over-volt conditions?

Does the pack have forged UL, CSA, RoHS, CE, IEC, and marks from other standards bodies? So many eBay sourced electrical products do. For that matter, so many no-name products originating in China share this same failing.

eBay is one of the last places I would suggest any lay person pick up lithium ion powered products. Alibaba and other direct from China sources would fill in for last place.

 

[Gauss163]

@Tandem The eBay packs are the same as you find in the stores. There appear to be only a handful of variants. I'm not aware of any jumper packs manufactured by reputable companies. In any case my remark was meant to address only market price - not safety (which, as you know, I addressed more generally in other active threads here).

 

[tandem]

Given the frequency of various counterfeit products being flogged on eBay and other on-line sources I would not wish to make a bet that what's for sale on the auction site is the same as is found in a bricks and mortar store in North America even if they compare identically at a superficial level.

Worse, having four walls and a store full of products is no guarantee that what's for sale was built correctly and has appropriate, legitimate, certification. Bad stuff gets imported by wholesalers and retailers all the time. Few merchandisers trouble themselves with such things, and counterfeit UL, CSA and other marks are common.

It's not just the on-line sources that need to be viewed with caution, these days.

 

[StandardBattery]

Re: Battery Jumpstarters

They are built with high-current (RC) LiPo cells, which can indeed supply adequate jump start current. See any of numerous youtube video demonstrations, and many Amazon reviews expressing great surprise that such a small battery can start a car (which shows how little intuition the general public has about the power of Li-ion batteries).

As for the capacity, it is usually exaggerated (typical for Chinese batteries). But capacity matters little for burst-current apps like jump starting.

Btw, some of the Amazon reviews are ridiculous, e.g. see these comments, where the first comment by the seller gives a disingenuous excuse for capacity fraud, and someone swallows hook, line, and sinker, with a bogus gas tank analogy. Perhaps someone with an Amazon account can point them to more knowledgeable forums, e.g. here.

No doubt seen all those and I have my own (2 now just for fun), but that one looked aimed more to charging that jumping even if it could do a jump. I didn't look at it too much just the general impression from it, but it may be as good as the average at jumping also.

 

[WalkIntoTheLight]

Re: Battery Jumpstarters

No doubt seen all those and I have my own (2 now just for fun), but that one looked aimed more to charging that jumping even if it could do a jump. I didn't look at it too much just the general impression from it, but it may be as good as the average at jumping also.

I don't think "jumper cables" are really meant for starting an engine, alone. My jumper cables look to be 8 gauge wires, about 4 feet long? There's no way they can supply the current needed to start an engine, without a huge drop in voltage across them. I think jumper cables are really for giving your car battery a bit of charge, and most of the current actually comes from your own car battery when you start the engine, with a bit of help from the boosting battery.

I've never tried this, but I don't think you'd be able to start an engine if you disconnect your own battery, and try to just use the boosting battery connected to jumper cables. Not with typical cheap jumper cables, anyway.

 

[chazz]

Re: Battery Jumpstarters

I don't think "jumper cables" are really meant for starting an engine, alone. My jumper cables look to be 8 gauge wires, about 4 feet long? There's no way they can supply the current needed to start an engine, without a huge drop in voltage across them. I think jumper cables are really for giving your car battery a bit of charge, and most of the current actually comes from your own car battery when you start the engine, with a bit of help from the boosting battery.

I've never tried this, but I don't think you'd be able to start an engine if you disconnect your own battery, and try to just use the boosting battery connected to jumper cables. Not with typical cheap jumper cables, anyway.

That is why if you want real jumper cables you will buy some heavier gauge cables, I made my own with 2/0 welding cable. They will indeed start a car even if that car has NO battery, I have done it more than a few times. I once jumped a diesel truck with my cables after the guy tried with his tiny "speaker wire" sized cables that would not even turn it over, needless to say he was impressed and was going to buy some more impressive cables.

I Think these Li-ion jumper packs are a great idea for the just in case, plus you could use most of them to charge a phone or whatever which would be nice. I will probably be getting one at some point, just need to figure out what one is decent quality and good value.

I have read at least a couple articles talking about auto makers possibly switching to Li-ion batteries for the primary starter battery, the main reason for them is weight savings (weight saved is mpg gained). It would not surprise me to see something like this happen in the next 5-10 years, but who knows.

 

[Gauss163]

Re: Battery Jumpstarters

I don't think "jumper cables" are really meant for starting an engine, alone. My jumper cables look to be 8 gauge wires, about 4 feet long? There's no way they can supply the current needed to start an engine, without a huge drop in voltage across them. I think jumper cables are really for giving your car battery a bit of charge, and most of the current actually comes from your own car battery when you start the engine, with a bit of help from the boosting battery.

I've never tried this, but I don't think you'd be able to start an engine if you disconnect your own battery, and try to just use the boosting battery connected to jumper cables. Not with typical cheap jumper cables, anyway.

But I've read many reviews that claim success starting a car with just the jumper pack (no car battery). In fact, some say that it is necessary to disconnect the car battery when the jumper pack is low (so that all of the jumper's juice goes to starting the car, and not also charging the car battery).

The common jump cables in the photos I posted use about 1 foot of 10 AWG wire and EC5 connectors. Here's what one RC site claims for their 10 AWG

This 10 AWG wire is rated for 8 min continuous 130 Amps with 10mph x 80degF air flow, and 200 Amp burst rating for 5 seconds provided the average current (including the bursts) is not more than 80 Amps.

 

[chazz]

Re: Battery Jumpstarters

But I've read many reviews that claim success starting a car with the jumper pack alone. In fact, some say that it is necessary to disconnect the car battery when the jumper pack is low (so that all of the jumper's juice goes to starting the car, and not also charging the car battery).

The common jump cables in the photos I posted use about 1 foot of 10 AWG wire and EC5 connectors. Here's what one RC site claims for their 10 AWG

I have personally done this as well, worked at an auto body shop for a few years, and often we would need to start and move a car with no battery in it. At that point the jump pack we used was a AGM (sealed lead acid) based and was probably 20+ lbs. I would be curious how well one of these smaller Li-ion units would hold up to actual use.

The shorter the cable the more current it will carry vs a longer cable, so a jumper pack with fairly short cables will still handle decent current. Obviously if you are trying to start a big diesel tractor or some other equipment that normally has huge primary batteries you will need some different equipment to jump it, but most of what we are talking about is regular autos, cars etc.

 

[SubLGT]

Re: Battery Jumpstarters

NOCO has entered this market with their Genius Boost GB30 Ultra Safe 400A device. I could not find any specifics on the Li-ion cell they are using, other than it having a 24Wh capacity.

http://www.geniuschargers.com/boost

 

[Lynx_Arc]

Re: Battery Jumpstarters

24Wh is pretty small considering SLAs in even the cheap starters are most likely 12v 10Ah or 120wh. It sounds like it may start a car that starts easily but if one needs to crank a few times for a few minutes the battery may not have enough power to do that as many car batteries have in excess of 700 cranking amps for when it gets really cold outside

 

[bella-headlight]

Re: Battery Jumpstarters

I watched my local garage start a Mitsubishi L200 3 litre turbo diesel (higher compression than a petrol motor so harder to turn over) with just one of these (no regular battery connected) http://www.ebay.co.uk/itm/Mini-3000...908?pt=LH_DefaultDomain_3&hash=item48778eddcc
The engine had just had a top end re-build & this was the first start.
Turned the motor over fast.
He left the jump pack connected for several minutes with the engine running although I see from the advert that it states to remove after 30 seconds ?
I must admit that I am tempted to get one as a "just in case" item as they are so easy to carry.
In fact I am thinking of getting 2, one to leave in my car & one to leave on my boat.

 

[Lynx_Arc]

Re: Battery Jumpstarters

I watched my local garage start a Mitsubishi L200 3 litre turbo diesel (higher compression than a petrol motor so harder to turn over) with just one of these (no regular battery connected) http://www.ebay.co.uk/itm/Mini-3000...908?pt=LH_DefaultDomain_3&hash=item48778eddcc
The engine had just had a top end re-build & this was the first start.
Turned the motor over fast.
He left the jump pack connected for several minutes with the engine running although I see from the advert that it states to remove after 30 seconds ?
I must admit that I am tempted to get one as a "just in case" item as they are so easy to carry.
In fact I am thinking of getting 2, one to leave in my car & one to leave on my boat.

If that is truly 30,000mah or 30Ah then it is about 360 watts which has more available power than SLA packs. I think there is two things needed... high current capability and enough capacity to sustain cranking long enough to start an engine. Most engines these days start a lot easier than older engines but if you did get a car that has a hard time starting some of these packs may poop out after the pack depletes. a 30Ah pack that is turning an engine that takes 400-500 amps can theoretically maintain cranking for about 6 minutes or so but one thing to consider is that battery packs wear in time and capacity is reduced so half way through the life of the pack your 6 minutes of cranking time may drop to closer to 3 minutes which would have you needing to recharge it after every use. I have a feeling we will see more and more of these lion packs in stores as people will be more impressed by the small size and claims than realizing the actual use of them may not meet up with expectations a few years down the line.

 

[Gauss163]

Re: Battery Jumpstarters

If that is truly 30,000mah or 30Ah then it is about 360 watts which has more available power than SLA packs..

30Ah is at the nominal 3.7V, so it would be 30Ah * 3.7V = 111Wh. But the capacity on these packs is usually exaggerated, as for most Chinese cells from nonreputable sources. It is probably 40-50Wh at best.

 

[Lynx_Arc]

Re: Battery Jumpstarters

No, 30Ah is at the nominal 3.7V, so it would be 30Ah * 3.7V = 111Wh. But the capacity on these packs is usually exaggerated, as for most Chinese cells from nonreputable sources. It is probably 40-50Ah at best.

That would make some sense as I'm guessing the average 18650 sold in stuff worth anything is about 2000mah it would take 15 of them to equal 30Ah and they would be in 5 strings of 3 or 4 strings of 4 which would reduce the capacity at 12v down to 1/3 or 1/4 of the 30Ah figure lets say 7.5-10Ah.... which to me is not any better than a decent SLA pack and I certainly don't think 18650s can take nearly as much abuse as SLAs can.

 

[Gauss163]

Re: Battery Jumpstarters

Yes, one can often refute bogus capacity claims just by doing simple arithmetic that shows the energy density would be higher than the current known limit for Li-ion cells.

You managed to quote me during the two minutes before I fixed the typo: it should say 40-50Wh (not Ah).