Pocket jump start !!

[normspanners]

WELL it had its first test THIS MORNING the wifes Merc ran perfect on Sat then today nothing, didnt even try , she is screamin at me I'm gonna be late --------so no problem---------- I have my pressie, connected up and she fired straight away,
I didnt put it in the car case I need it (my excuse) hopefully it won't start for her to come home tonight then I can have some peace.

DAMN forgot they have one at work!!! thats where she got the idea.

 

[Cobbler]

HA HA -------If my back was turned I would see them!!!

I know a few that can talk out of there Norm, but to be able to see out of it must be a biological miracle. It explains the expression "I've got mud in my eye" though.

 

[normspanners]

WELL BLOW ME----- that is not an invitation BTW -------
The lad went out this morning at 6 had a low tyre, he opened the disco to get tyre inflater out and left the lights on, so I had a flat battery!! it was cranking but not fast enough for the diesel to fire from cold.
I thought this will be a test put the pack on it and bingo away she went.
Well chuffed with it.

 

[Migmac]

Sounds like a really handy bit of kit, nice to see someone getting a pressie that's useful

 

[awemawson]

I'm really pleased that it's worked for you (now at least twice) but I find it hard to understand how it can. From reading the specs iirc it can deliver 600 amps for 3 seconds but is only about 17 ampere hours capacity. I can only assume that it has an ultra low internal resistance. When things seem too good to be true they usually work out to be just that. This sounds such a handy thing to have on the farm on a cold morning - but how does it work?

 

[normspanners]

AFAIK it is the battery formation lipo they are now used for model airplanes etc where you can fly battery powered planes for long periods etc
the wifes boss Dave could not believe it when at a drifting meeting, a car would not start and this guy got, in daves words, a fag packet out and was about to start the car dave said F couggh, I'll get the jumper leads and bring mine over before he could walk a metre the car was running and the bonnet down, hence the garage has one now.
And thankfully me

 

[Pete.]

I was doubtful when I first saw mine too, a plant fitter went to hand it to me and I said "No mate, I meant your booster pack". He smiled and said that he had the same reaction when he first saw one, so the rep told him to take the battery off his Transit, hooked this up and started the van 3 times in a row.

 

[Maker]

I'm really pleased that it's worked for you (now at least twice) but I find it hard to understand how it can. From reading the specs iirc it can deliver 600 amps for 3 seconds but is only about 17 ampere hours capacity. I can only assume that it has an ultra low internal resistance. When things seem too good to be true they usually work out to be just that. This sounds such a handy thing to have on the farm on a cold morning - but how does it work?

A 16.8 ah battery could in theory supply 600 amps around 141 seconds (But I doubt it could as it would overheat/go wrong in some way).

AFAIK it is the battery formation lipo they are now used for model airplanes etc where you can fly battery powered planes for long periods etc

I don't think LiPo is used much for RC any more, lithium ion and lithium ferro-phosphate (LiFePo4, a better type of Li-ion) are more common because they hold their charge longer and are safer (Lipo have been known to explode if overcharged).

 

[normspanners]

What are LiPo batteries and why are they so popular in the RC world?
LiPo batteries (short for Lithium Polymer) are a type of rechargeable battery that has taken the electric RC world by storm, especially for planes, helicopters, and multi-rotor. They are the main reason electric flight is now a very viable option over fuel powered models.

RC LiPo batteries have three main things going for them that make them the perfect battery choice for RC planes and even more so for RC helicopters over conventional rechargeable battery types such as NiCad, or NiMH.

• RC LiPo batteries are light weight and can be made in almost any shape and size.
• RC LiPo batteries have large capacities, meaning they hold lots of power in a small package.
• RC LiPo batteries have high discharge rates to power the most demanding electric motors.

In short, LiPo’s provide high energy storage to weight ratios in an endless variety of shapes and sizes.

 

[Maker]

In that case, I take it back then. I only (think I) know what I do from about a year or two ago when I looked into building a Quadcopter.

 

[normspanners]

I dont know, I just took that from here http://www.rchelicopterfun.com/rc-lipo-batteries.html

Differences in Lithium Ion (Li-Ion) Lithium Polymer (LiPo) batteries.
In the RC world today, most battery packs are of the LiPo type. I thought I should include a short discussion on the Li-Ion type of pack just in case you come across one as they are used in some higher end radios. Li-Ion and LiPo batteries have essentially the same chemical make-up, they both rely on lithium ion exchange between the lithium carbon cathode & anode, and are cared for in the same way; the primary differences are in how the cells are packaged and the type of electrolyte that is used.

Li-Ion

Li-Ion batteries use a flammable solvent based organic liquid as the electrolyte. This electrolyte is responsible for the lithium ion exchange between the electrodes (anode and cathode) just like any type of battery. Li-Ion batteries are usually encased in a hard metal can (again like a more conventional battery) to keep the electrodes wound up tight against the separator sheet adding weight and not allowing many different options as far as shape and size.

LiPo

A true LiPo battery doesn’t use a liquid electrolyte but instead uses a dry electrolyte polymer separator sheet that resembles a thin plastic film. This separator is sandwiched (actually laminated) between the anode and cathode of the battery (lithium carbon coated aluminum & copper plates) allowing for the lithium ion exchange – thus the name lithium polymer. This method allows for a very thin and wide range of shapes and sizes of cells.

The problem with true LiPo cell construction is the lithium ion exchange through the dry electrolyte polymer is slow and thus greatly reduces the discharge and charging rates. This problem can be somewhat overcome by heating up the battery to allow for a faster lithium ion exchange through the polymer between anode and cathode, but is not practical for most applications.

If they could crack this problem, the safety risk of lithium batteries would be greatly reduced. With the big push towards electric cars and energy storage, there is no doubt some pretty huge developments will be made in ultra light weight dry and safe LiPo’s in the coming years. Seeing that theoretically this type of battery could be made flexible, almost like a fabric, just think of the possibilities.

LiPo Hybrids

All RC LiPo batteries out there at the time of this write up (March 2014) are actually a hybrid lithium polymer battery. The correct name for this type of battery is lithium-ion polymer, but the battery world of today simply calls them lithium polymer even though they are not a true dry type LiPo battery.

By introducing a gelled organic/solvent based electrolyte to saturate the polymer separator, the lithium ion exchange rate between anode and cathode is improved immensely. LiPo hybrids like Li-Ion can still burst and catch on fire if over charged, shorted, punctured, or incinerated.

When first introduced, LiPo batteries were more expensive than Li-Ion because they are more labor intensive to manufacture. Fortunately prices have dropped substantially since they have become as, if not more popular than Li-Ion battery technology. This holds especially true for electric powered RC aircraft and the real driver behind LiPo battery research – portable communication/entertainment devices.

LiPo hybrids use the same flat cell structure as their dry counter parts meaning they have the same flexibility with sizes and shapes allowing for very specialized shaped battery packs perfect for use in our RC models.

Almost every RC LiPo battery cell is packaged in a foil pouch coincidentally called a pouch cell. The picture to the right shows a typical 2 cell LiPo RC battery pack.

Pouch cells are the perfect solution for building multi celled battery packs since the flat pouch cell can be stacked with no wasted air spaces like found within round celled battery packs. Of course since LiPo’s use this light weight pouch instead of a metal can, less weight is the result making LiPo’s the preferred choice over Li-Ion in a weight conscious application such as RC aircraft.

43
If you ever open up a LiPo foil pouch cell, this is what you will find. A long piece of very thin plastic film (the polymer) with the thin lithium carbon coated aluminum & copper anode & cathode electrodes laminated in an alternating pattern on the front and back side of the polymer separator film. The works will be saturated with the greasy solvent based organic electrolyte.

This long film (over 7 feet long in the case of this 5000 mAh cell), is then folded accordion style back and forth upon itself. The entire folded cell matrix is then heat sealed into the foil pouch along with the gelled electrolyte which incidentally has a very sweet solvent smell much like nail polish remover/acetone.

If you're wondering what the burnt hole is in the center of all the cell folds, I purposely drove a nail through this cell to discharge it rapidly & watch the fireworks. The cell rapidly ballooned out, burst, and vented a fair amount of flammable electrolyte but never caught on fire. On the positive side, if it would have burst into flame, I wouldn't have this picture to show the "guts". I only did this because I dropped this heavy 6S 5000mAh LiPo pack on the hard concrete floor (yes - very dumb & costly butter finger moment) and one cell was damaged in the process. Lesson learned, don't carry more LiPo's than you can safely hold!

Here's a good video of the processes involved in manufacturing LiPo cells & packs.


One interesting characteristic hybrid LiPo batteries share to an extent with their dry counterparts is they do get more efficient at ion exchange once warmed up. If you have ever noticed your RC model seem to gain a little more power a minute or so after working the battery; what you are experiencing is the increase in ion exchange efficiency once the battery chemistry warms up.

This should have you thinking that if you fly your electric RC helicopter or plane in the winter time, you might want to keep your RC LiPo battery packs in a warm place prior to the flight.

 

[Paul99]

Hmm think I got to seriously consider getting one of these - I had a nightmare getting vehicles started today. How long do they take to re-charge? not that it matters all that much but just curious and I couldn't see it mentioned anywhere.

 

[Bill Edwards]

They really do look too good to be true.
I'd like one to try on the tractors when they don't go, starting cars is one thing but I think that big, cold diesels must be too much?

 

[Paul99]

Well it's been a year or so since these fluoreon packs were mentioned. Is yours still working ok Normspanners? mine was faultless until my brother "borrowed it" and cooked it cranking an engine over and over over until the solder on the crocodile clips melted livid isn't the word - well it knackered the battery too, it seems, as it will not hold any sort of charge any more... Some people just don't have any common sense.

 

[awemawson]

... but he's presumably replaced it for you. So how's the new one doing ........

 

[Paul99]

... but he's presumably replaced it for you. So how's the new one doing ........

Has he hell - he reckoned that it's not his fault if it can't turn a 2l tdi over for a few minutes What was worse was he handed it back and neither he or the old man, who it turns out was his partner in crime, said nothing at all until I went to use it again myself the air most certainly turned blue which is unusual for me - livid wasn't the word.

He doesn't even ask to borrow tools now as he knows what the response will be....

Back to the point of reviving the thread - I plan to buy another and absolutely keep it to myself. I just wondered how the batteries fare with careful / proper use as batteries always seem to be the weak point with cheap tools.

 

[awemawson]

... you can choose your friends but you're stuck with your relatives

 

[Robotstar5]

Back to the point of reviving the thread - I plan to buy another and absolutely keep it to myself. I just wondered how the batteries fare with careful / proper use as batteries always seem to be the weak point with cheap tools.

Shop around on the bay and you can find them for £38ish now

 

[normspanners]

Mine seems to be fine but I have heard what damages them is flattening them then leaving the on the car whilst it is charging, you should disconnect asap because it over boosts them I have heard of a couple that have done that, I used mine only yesterday it was only to start charging a totally flat battery, some smart chargers wont kick in if the battery is absolutely flat.
My passat is aright pain if the battery is totally flat for some reason if the key is left in the ign it sometimes flattens the battery very quickly i think the engine heaters are still switched in like the relay sticks and if it is like that I have to use two sets of jump leads to fire it up. It is that amp hungry, strange thing is if the battery will turn it one compression it will start usually it is a cracking starter usually.

 

[AndyStobbs]

My standard battery test now is IGN and headlights on for 5 minutes. The quality of the start (or lack of) forms the basis of my battery report.
Fed up of the Picoscope test claiming every battery is knackered, or in need of recharging when I have just driven the car in, and it requires access to the often buried battery.