Postbag #20: Car Jump Starter, 600mAh LiPo, Pointer Knob

[@AnsyCrofts]

Retro pointer knob! Had two of those to tune my one-valve shortwave radio I made when I was about 12...(over 45 years ago). Happy memories - didn't know I could still get 'em. Pisser that, from Finland to UK they're a quid each, but four quid to post. I'll try from China. Free shipping, natch!

[@JerryEricsson]

I went out and got me one of those, well ordered it off Amazon.com, that exact model. The first few times I tried to jump start anything, it was my riding lawn mower, it worked fine for that, hell saved me the cost of a new battery for 2 years. Last winter, I headed South as we usually do, and drove from South Dakota to the Arizona/Nevada/California border. When I had just made it into California with our RV, we stopped at a rest area, to, well, rest. Using the RV for that purpose is OK but we needed to get out and walk a bit, stretch and all. My book on my Ford Edge that I towed behind our Class A Motor Home needed to be started at every stop and ran for 5 minutes to insure the transmission remained lubed. Well I jumped behind the wheel, as I had at every stop, and there was not even a damn CLICK! NOTHING. Well, I though, great place to try that booster deal. I got in the cargo area of the RV and retrieved the starter kit. I checked and she was showing a full charge, so I hooked her up, got behind the wheel of my Ford Edge, and turned the key. CLICK, CLICK, MAGIC SMOKE rising from the booster pack, as the cells in her began to swell, opening the case. I disconnected her and tossed her in the cargo area once more, then drove the last 100 miles to our RV park. A few hours on a battery charger and my Ford was on the road again. As far as the booster pack, after resting up, the swelling went down, i gave her a full charge, and she has been serving me as an impromptu 12 volt power pack, and 19 volt emergency laptop power package.

[@akhurash]

Interested in seeing how well the car starter works. I'm looking for a battery backup for a aquarium I have and I think I might be able to use that.

[@danljohnston]

Hi Julian, Not to influence your review of the Jumper Starter, but I have one (different brand name) and have used it 2 times to start my 50 HP diesel tractor. Now, I must say that the instructions clearly states that it is not meant for diesels. The reasons for this are their higher compression ratios and some models have glow plugs for preheat. I live in a warmer climate, so the glow plugs wasn't used. Also 50 HP is rather small for a diesel. The battery in my tractor was completely drained, because somehow I had left the key on. The little lipo pack started the engine instantly. I was amazed. Having said all of this, I wouldn't even try this on my diesel truck which is about 250 HP and uses 2-12 volt batteries in parallel.

[@MrBanzoid]

Ahhhh the good old chicken head knobs - I love them - very retro!

[@MyBigThing2010]

I wanna know how to build one of these jump starters with eBay components and a little bit of soldering

[@fuzzybobbles]

I've started a 2 litre Toyota Celica using a Turnigy Nanotech 5000mah li-po pack after flying my octocopter on a day out and flattened the car battery charging it a few times. The li-po was about 70% charged and coupled that with the little charge left in the car's battery just about started it and saved us from being stranded in Wales. I will look forward to seeing the full review of the jump starter.

[@JulianIlett]

fuzzybobbles I have a sneaking suspicion there will be a 3S radio control flight battery inside the box. I've not opened it yet, but I don't think I'll be able to resist cracking it open during the review.

[@fuzzybobbles]

Julian Ilett I think there will be too. The case seems very small for a 12,000mah pack though. Might be worth having a peek on the Hobbyking website as they sell single cells on there to make your own packs with and they give the dimensions of them for each type, so quite easy to estimate the capacity of the pack inside the jump charger.

[@1974Alfa5Spd]

The 60 in XT60 does in fact stand for 60 amps, there's also another, albeit incompatible version called the XT90, and then I think you have to move to the EC style connectors to get any more current. I've seen those big EC5 connectors on extraordinarily large multirotors and 1/4 scale electric aircraft, which can draw well over 200 amps.

[@tobortine]

I have a smaller jump starter that I always carry in the car - my phone and the number of the AA ;-) Enjoyed the video.

[@PilotPlater]

very excited to see that car starter in action. Would be incredible if it works as advertised. I would assume you only get one good try at it, but hopefully that's all you need if you just left the lights on.

[@PilotPlater]

Doing some quick math, assuming it was a perfect 1200mAh, you could pull 200 amps for 21.6 seconds, that's actually quite a lot. Considering you typically are only cranking the car for maybe 3 or 4 seconds you should be able to get a few tries in I would think.

[@Luke-san]

+1 seriously want to see proof that you can start a real car, not an rc car, with this. If it can instantly deliver a couple of 100 Amps it must be an extremely dangerous item to short circuit.

[@abyssunderground]

The videos I've seen of these and similar units is promising but I doubt it will start a large engine with a totally dead battery. I also wouldn't expect the pack to last long with repeated jump starts all the time as I don't think they're really built for it. It really is one of those emergency things I'd say. Definitely going to wait for the video though. It would be nice to get a clamp meter around it to see what sort of current it can really produce too.

[@JulianIlett]

Luc Peeters Yep, me too. I'll be starting my real Citroen C1 (small 998cc 3-cylinder petrol) with a completely dead battery. Should be fun!

[@PilotPlater]

Luc Peeters Indeed, when he put those scope probes on there I was thinking "oh noes what if that slips, looks like fun"

[@deangreenhough3479]

Looking forward to you testing this post bag

[@psp10004]

That heatshrunk box is probably hiding a high power diode, this prevents high current from flowing back in the LiPo (and possibly detonating it) once the engine starts.

[@JahanZeb1976]

Looking forward for Innori car start and unpacking review. Regards,

[@ELECTROHAXZ]

Where is your review on the jumpstarter?

[@extendedp1]

I am glad you got that mini jumper battery, I was going to suggest you get one after I watched your last power bank video :-). I hope you give it a thorough review, capacity tests too, maybe even open it up? Do you think it would be possible to hook 4 of them, in series to use as a 48v electric bike battery?

[@macro820]

Does sound like a RC lipo, most of them are 25c, ie. 25c x 12Ah = 300amps

[@bgdwiepp]

That type of knob is a "Chicken Head Knob" , i love it.

[@fabts4]

Did you end up testing the car jump starter then?

[@RobB_VK6ES]

I had a very nervous time soldering new balance leads to a LiPo just the other day. I now have a great respect for the people assembling these packs for a living :) One false move and it can get very exciting especially when you consider the propensity for these cells to self destruct when mistreated. BTW if you are in the market for a charger take a look at the turd igy 'Reactor' from HK, a very capable 300 Chinese watt charger with data logging and high rate discharging functions. Have a close look at the specs and I think you will agree the extra functionality is worth the extra cost especially given your interest in solar power and battery performance. Only problem is they are so popular they are always out of stock. Egg sucking time. When choosing a charger don't forget the theory of conservation of energy, input volts & current vs output volts & current vs power capacity of a boost buck charger. It's easy to be mislead by the headline charge current when they quote max volts and max current in the same breath. Which leads onto a possible topic for a future video. How to safely convert a PC power supply into a power source for these portable chargers. There are plenty videos out there on this subject but nearly all of them are at best dodgey to the downright dangerous. Produced by people with no real understanding of what they are doing.

[@JulianIlett]

Rob B Hi Rob - I'll be fitting balance leads to my LiFePo4 pack when I can afford to buy it. It'll be an 8S pack, so a 9-way connector. Unfortunately that rules out the Reaktor charger as it's only available as a 6S. So the Accucel 8S still looks like the favourite.

[@stevefox3763]

The XT60 is officially a 60A connector but in the RC world we regularly exceed that draw by a significant amount. My 450 size quadcopter is not by any means the most current thirsty out there and I pull just over 90A at full throttle, there are quads that pull substantially more current than that :) I have a large scale fixed wing which also pulls substantial current at full throttle @ 82A, full throttle on that is something which unlike a quad is often sustained for extended periods and the connector handles it just fine. I'm not sure what I think about lipo powered car starters, whilst lipos have a large energy density and can deliver massive current, they should not be left fully charged and should be stored at 65% or 3.85v per cell otherwise they sustain rapid degradation and internal resistance buildup, a car starter you need to charge before you use it isn't much use for sudden need cases! A lead acid might not be as small or hold the capacity per cc of space taken up but they can and should be stored fully charged and can still deliver substantial current albeit for a shorter period of time.

[@jusb1066]

it would always lose position when the cpu powers down, it cannot see the absolute position, but there is another switch that can do so, the absolute rotary encoder

[@JulianIlett]

jusb1066 True, it will always lose position through a power cycle, but it really ought to be able to hold sync during normal use.

[@jusb1066]

Julian Ilett these are mostly used as a volume or menu select, if they miss the odd once it doesnt matter at all , i am surprised as you was, that they are not optical but mechanical

[@christopher4636]

I'm guessing it must be one large Lipo pack in that jump starter. Perhaps a 11.1V (3S) pack with a rating of something like 35C on a 5500mAh pack. That would give you a discharge current of 192amps at 12.6V when fully charged and around 12Ah at 5V. While that's ample current and the capacity is probably OK I'm not entirely convinced yet so I really look forward to your full review of it. The 10AWG wires are a bit smaller than most found on jump packs but they should be just fine as they're only a few inches long and good for 200A at that length. If you start your car using it combined with a dead car battery I'd be interested to know just how low the voltage drops under load. Also please be careful Julian, if you connect that thing to a completely dead car battery then it's gonna instantly try and put a LOT of amps into your dead car battery as I'm sure you know, while I'd be happy doing this with longer cables (-ve clamp on an earth point) and using a normal lead acid jump pack I'd personally be uncomfortable using a lipo as they're inherently a lot less stable.

[@oreubens]

quick guess says it doesn't use LiIon 18650 cells but instead uses the same type of high discharge lipo's used in RC.

[@flash001USA]

10 AWG is rated at around 15 amps. What they are doing is using the power pack to work in unison with the car battery. If you have a dead battery that has lost it's ability to hold any current it probably will not crank the car.

[@JulianIlett]

flash001USA I'm very tempted to attempt starting the car with NO lead-acid battery at all. The chart I looked at had 55A for 10AWG cable - www.powerstream.com/Wire_Size.htm

[@flash001USA]

Julian Ilett "Maximum amps for power transmission" ---> POWER TRANSMISSION

[@flash001USA]

Julian Ilett I forgot to mention this. You may be able to crank the car with just the starter pack but it will be extremely hard on the starter pack and possibly damage it so be careful.

[@smallenginedude71]

remember its silicone coated

[@flash001USA]

smallenginedude71 What does the silicone do?

[@Zentrius]

can you maybe give some feedback about the actual capacity of the lipo battery since they usually print fake nubers on there :) its probably more around 400mah (hope not :))

[@JulianIlett]

Zentrius I'm very close to buying an 8-cell LiPo charger (Turnigy Accucel 8). If it can do single cell discharge testing, I'll measure it.

[@Zentrius]

simple and cheap imax b6 clone(20$) just works fine im happy with it and its quite accurate. but only 6 cells

[@JulianIlett]

Zentrius That would be my first choice. But my electric bike project looks like it will have 8 cells LiFePo4 in series. There aren't many 8S chargers to choose between.

[@RobB_VK6ES]

Julian Ilett Charge as 2 - 4cells in parallel and connect in series in use. works a treat.

[@CraigOverend]

Julian Ilett I have a B6 and it works well but now wish I had an 8. I discovered I can data log with my B6 using the donationware LogView Studio if I plug into a USB/Serial to TTL (haven't yet). I believe the Accucell 8 is also supported, but don't quote me on that. :)

[@smallenginedude71]

awesome stuff!

[@smallenginedude71]

it would be an rc 11.1 3s lipo verrry high curent discharge

[@JulianIlett]

smallenginedude71 Yep. It is.

[@smallenginedude71]

Julian Ilett i have 3 of them in my ebike, they are great.

[@Mandrag0ras]

Isn't the car jump starter too small to have the energy of 15 high current 18650 cells? 12000mah sounds way too much.

[@poptartmcjelly7054]

You should consider getting a Li-Ion battery instead of a Li-Po because Li-Ions have 50% higher energy density, thus you can make em 50% smaller than what a Li-Po would be.

[@ForViewingOnly]

Incredible that this small lithium battery jump starter could produce enough current to start a car! Hope you can do a teardown & explanation Julian. Would the jump starter contain Li-Po batteries rather than Li-Ion? From my limited understanding, Li-Po batteries are used for high current applications, quicker discharge applications. Also, how dangerous are Li-Po batteries really? Some RC Model forums tell stories of batteries spontaneously combusting, and people storing them in metal boxes when not in use. In fact, can anybody recommend a link for learning about the difference between Li-Ion and Li-Po batteries... there's so much conflicting information out there that it's hard to separate the wheat from the chaff!

[@JulianIlett]

ForViewingOnly I'm sure Dave Jones once said there's no actual difference between LiPo and Li-ion. Wikipedia seems to unravel this pretty well in the first few paragraphs - en.wikipedia.org/wiki/Lithium_polymer_battery

[@ForViewingOnly]

Julian Ilett Thanks Julian. Ah, no wonder there was confusion if 'Li-Po' had two meanings. As you say, the more popular definition (polymer pouch) means that the Li-Po is effectively the same as the Li-Ion, apart from the outer case material.

[@haydenc2742]

LiFePO4 3.6vdc batteries, not the typical 18650 Li Ion you would find in laptop or cordless tool packs. Very cool little jump starter kit. en.wikipedia.org/wiki/Lithium_iron_phosphate_battery

[@bruceberadino]

looks like that thing would kick ass on a motorcycle

[@theduosolution93]

If you by a 12ah lipo battery from china just multiply it by 0.6789 Then you have the correct amp (In thaiwan its 0.6345)