Portable Power Jump Starters

mjt57 · Senior Member

Portable Power Jump Starters

Roving-Dutchy · Guru

The claims made for these power packs seem to be quite extraordinary some are claiming a capacity of 50 ah and why this is always quoted in milliamps seems to be just to exaggerate the capacity even further.
The latest drill batteries now have a capacity of 5 ah and these power packs are stating 10 times that, maybe I have been out of the loop too long but this seems a massive improvement in a package that is even smaller than the latest 5 ah battery packs.
I did buy one of these units about 12 months back and it wouldn't even start a 12.5hp lawn mower.
I doubt that one of theses units would be capable of running a CPAP machine for anymore than about 30 minutes.
Cheers
David

jade46 · Senior Member

How could the leads shown in the picture carry enough current to start a diesel or any engine. Does not seem possible

mjt57 · Senior Member

The guys who bought them are sparkies and very smart. They explained that the leads, which are 6mm2 are short enough to carry the load for a few seconds. As for the amp hour rating if it's accurate they only need to generate a couple of hundred amps for a few seconds, I S'pose. Whereas the 5ah battery will need to deliver its output over s much longer period. Eg. I can get about an hour or so out of a 3ah Makita battery driving an impact driver when screwing down decking timbers. Anyway when the lads get to test them I'll post some feedback. Hopefully it'll be positive.

Aus-Kiwi · Guru

Trouble is batteries don't generally discharge that fast . Unless there's capacitators built into pack..
It will start a diesel if main battery is 3/4 charged..
I know it WONT. Start my 6.5 GM diesel... 6mm carries bugger all amps at 12v ...

Roving-Dutchy · Guru

The amp per hour rating is not an indication of the max amps a battery can deliver but denotes how long a 1amp discharge can be maintained re 5ah = 1amp for 1 hour so if one of these units states 50ah it is not possible that it can maintain a discharge rate of 1 amp for 50 hours rate from a unit of this physical size.
Cheers
David

JackoFJR · Senior Member

I have a Mini Jump Starter , l said on another forum it was rated @ 13800Mah and 600Amps ,
Someone replied that is doesn't add up , a mate has borrowed it , so l can't check ,
I'm sure l have the 13800Mah right , the 600A , l probably have that wrong , might only be 300Amp .

Anyway , l have run my Philips Rem Star Pro , CPAP , for over 9 hours with it .

I have only started a dead flat Suzuki 4x4 with it , it fired up instantly.

JeffRae · Guru

We carry one of these with us...........www.bcf.com.au/online-store/products/XTM-Jump-Starter-1900A.aspx

Haven't used it on our car yet, but have started a Landcruiser with it. It's a bit bigger and heavier than the ebay models

-- Edited by JeffRae on Monday 9th of November 2015 10:00:19 PM

Hey Jim · Guru

Hi All,

Why bother if you have a generator with a DC built in battery charger. We take our Honda on all trips with us. Yes you may be delayed an hour or two but will see you on your way.

Regards Jim

mjt57 · Senior Member

Hey Jim,

Whilst a generator is indeed a handy item, it's also expensive and heavy. My current interest is more in day-to-day driving (van/camping use will come later). For example, my daughter's car's battery failed on her when she was taking the kids to school. Ended up walking them home in the rain. Husband was at work and too far to come home to fix it. Her RACV membership had expired.

First thing that we did when she rang, in tears, asking for help (we're further away than her husband), was to get online and to renew her RACV Roadside Assist for her. They turned up afterwards and got the car running. Diagnosed a failed battery.

If these portable packs work as claimed, one of them in the boot would've avoided a lot of grief.

mjt57 · Senior Member

JeffRae wrote:
We carry one of these with us...........www.bcf.com.au/online-store/products/XTM-Jump-Starter-1900A.aspx

Haven't used it on our car yet, but have started a Landcruiser with it. It's a bit bigger and heavier than the ebay models

-- Edited by JeffRae on Monday 9th of November 2015 10:00:19 PM

That also looks like a handy item. I'll have to pop up to the local BCF for a look-see. Although when I was there on Friday I didn't see many electrical gadgets like that.

How heavy is it? And dimensions?

mjt57 · Senior Member

Roving-Dutchy wrote:
The amp per hour rating is not an indication of the max amps a battery can deliver but denotes how long a 1amp discharge can be maintained re 5ah = 1amp for 1 hour so if one of these units states 50ah it is not possible that it can maintain a discharge rate of 1 amp for 50 hours rate from a unit of this physical size.
Cheers
David

Er, 5ah usually means 5 amps for one hour or 1a for 5hrs.

The featured pack that I posted a link to is around 50ah, I think it was. If you were to base the current capacity on this, then a starter motor drawing 300a would see the battery pack flattened after 576 seconds if my arithmetic is correct. ie. divide 300 into 50 then divide that figure into 3600 (seconds in an hour).

Honestly, I don't know if this is correct or not. And I'd have to say that I don't know what condition that either the battery or its cables would be in after such a workout.

I'm waiting to hear from the mate who bought the above item to see how he went jump starting his backhoe with it.

JackoFJR · Senior Member

mjt57 wrote:
Hey Jim,

Whilst a generator is indeed a handy item, it's also expensive and heavy.

If these portable packs work as claimed, one of them in the boot would've avoided a lot of grief.

Exactly ,they are cheap , take up no room and weigh bugger all , they do seem to work as advertised.

A mate who has a garage as a business, he used to have the trolley with a heavy 12 volt battery , to jump start cars

He now uses one of these mini jump start packs ,

Jaahn · Guru

JeffRae wrote:
We carry one of these with us...........www.bcf.com.au/online-store/products/XTM-Jump-Starter-1900A.aspx

Haven't used it on our car yet, but have started a Landcruiser with it. It's a bit bigger and heavier than the ebay models
-- Edited by JeffRae on Monday 9th of November 2015 10:00:19 PM

Hi biggrin

I have carried a similar old style jump starter for years as I only drive autos. They have a small AGM battery in them so they are a bit heavy and bulky, but work OK for jump starting and as a portable source of 12v for tv or charging phones etc. Usually have a battery with about 7 to 12+ Ahr capacity. I guess I have jump started dozens of vehicles big and small with them. You just have to remember to charge them every now and then. wink I think mine is about 10Ahr.

These new little suckers look very interesting as they are very small and light. AFAIK they have lithium power tool type batteries. Known technology but not usually in the capacity sold here. The capacity of them has rapidly increased from about 7000 mAhrs(7 Ahrs) a year or two ago, up through 16 to now 50Ahr. Where will it end ? Do they actually produce this ? Someone buy them and let us know. cry They certainly would be good if they work as promised. They would be better and smaller and cheaper than my current jumpstarter.

Jaahn

-- Edited by Jaahn on Wednesday 11th of November 2015 09:47:18 AM

dorian · Guru

http://www.ebay.com.au/itm/261933538956?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Battery Weight: 440g
Battery Size: 165 x 79 x 40mm
Starting current::: 300A
Peak current::: 600A ( 3S)
Capacity: 50800mAh

The battery dimensions are exactly the same as the case, so something is wrong there.

I compared the claimed specs against those of other batteries. In the following table it would appear that there is a close correlation between a battery's weight and its Ah capacity.

http://www.ev-power.com.au/-12V-LiFePO4-Batteries-.html

GBS	12V			Bolt	
Model	Capacity	Weight	Size WxLxH	Size	BMS module

LFMP20AH	20Ah	3.2kg	180x77x165mm	M5	CB-LFP
LFMP40AH	40Ah	6.8kg	197x127x190mm	M4x4	CB-LFP/CBM-LFP
LFMP50AH	50Ah	7.2kg	197x127x204mm	M4x4	CB-LFP/CBM-LFP
LFMP60AH	60Ah	9.2kg	273x128x192mm	M4x4	CB-LFP/CBM-LFP
LFMP100AH	100Ah	12.6kg	273x128x245mm	M4x4	CB-LFP/CBM-LFP
LFMP160AH	160Ah	21kg	280x290x190mm	M8	CBM-LFP
LFMP200AH	200Ah	27kg	280x290x245mm	M8	CBM-LFP
LFMP300AH	300Ah	46kg	365x270x320mm	M8	CBM-LFP

Using the 20Ah LiFePO4 battery for comparison, an equivalent battery weighing 440g would have a capacity of ...

20 Ah x (440 grams / 3.2 kg) = 2.75 ampere hours

Sealed lead-acid gel batteries weigh about twice as much as the LiFePO4 types, so a 440g SLA battery would have a capacity of around 1.4 Ah.

http://www.master-instruments.com.au/category/Sealed_Lead_Acid_Gel_Batteries/1553

The device also has a "12V - 1A charge input" which would suggest that it would require more than 2 days to charge a dead flat battery.

-- Edited by dorian on Wednesday 11th of November 2015 10:11:20 AM

Roving-Dutchy · Guru

The trade practises people should be going these sellers for misrepresentation, battery technology may have improved but certainly not to the extent claimed by these sellers.
Cheers
David

dorian · Guru

It appears that these generic "High Power" jump starters are manufactured by Wuhai. Here are the results of a charge/discharge test by a user:

Test capacity on car jump starter:
budgetlightforum.com/node/40676

The car jump i bought had a claimed capacity of 16800mah. (it is write 50800mah on it but seller told me it is 16800)

First, i tested it using the usb port on it and applied a 1A discharge on it.

After 5800mah, the test ended and no more power was coming out of the usb port and the power led show no more power

I charged it again and i hooked my accucel to the car jump clip and run a discharge test at 2A. The power bank go down to 8.13 volt getting only around 5000mah.

Trying to charge using the regular charger did not work ...
So i tried charging using my accucel and after only 3500mah, the cell inflated.

-- Edited by dorian on Wednesday 11th of November 2015 03:42:53 PM

dorian · Guru

I decided to open the battery bak and guess what, it is 3 x 4000mah cell in it :

https://www.dropbox.com/s/yufyawogf00omfq/2015-07-13%2015.08.30.jpg?dl=0

That's 3 x 3.7V / 4Ah lithium polymer batteries in series, which is 11.1V (nominal) at 4Ah in total.

-- Edited by dorian on Wednesday 11th of November 2015 05:04:14 PM

mjt57 · Senior Member

Just spoke to one of the lads who bought these power packs. He just started a Magna with his. It cranked over for 5 seconds, then stopped as per the instructions. Waited about 20 seconds then on the third or so engine rotation it started.

The leads were warm but not hot to melting or whatever.

Now, that's a 4 cyl petrol engine. Also, the car's battery wasn't in the car. Just the power pack connected to its leads. If it had a dead flat battery in it then it may struggle (any battery would as it's a considerable load in itself).

The one that he has is claimed to be able to start diesels. But of course there are limitations to that. It might start my Hyundai i30 (1.6 turbo diesel) but it may or may not start my Jeep (3.0l turbo diesel). I don't know and really, until the day comes that I have a set of jumper leads and another car handy, it's not something that I'd like to test. ie. these things would be a first resort, then backup from RACV Roadside or friend with jumper leads last.

I asked him to perform a test and to flatten his Prado's battery and give that a try. He politely said "no".

JeffRae · Guru

Hi mjt57, the unit from BCF is 330mm wide x 190mm deep x 350mm tall - weighs aroung 10-12kg

(Still trying to find some way I can get notifications from the forum)

dorian · Guru

I notice that the discharge current rating for the 3.7V 4Ah LiPo battery pack is 40C. That's 160A (= 40 x 1C = 40 x 4A). These are the batteries of choice for remote controlled sport applications.

Understanding RC LiPo Batteries:
www.rchelicopterfun.com/rc-lipo-batteries.html

As a very general guide line, 25C to 30C discharge rated packs are the norm for most 250-450 size electric helicopters with general to light sport flying in mind. For larger birds, 30C to 35C discharge rated packs are a safe bet (again for normal to light sport). Once up to aggressive sport or 3D, that is where the 40C and up discharge rated packs come into play.

I see several battery packs that are rated at 40C for "continuous" discharge and 60C "burst".

Jaahn · Guru

dorian wrote:
It appears that these generic "High Power" jump starters are manufactured by Wuhai. Here are the results of a charge/discharge test by a user:

Test capacity on car jump starter:
budgetlightforum.com/node/40676

The car jump i bought had a claimed capacity of 16800mah. (it is write 50800mah on it but seller told me it is 16800)

First, i tested it using the usb port on it and applied a 1A discharge on it.

After 5800mah, the test ended and no more power was coming out of the usb port and the power led show no more power

I charged it again and i hooked my accucel to the car jump clip and run a discharge test at 2A. The power bank go down to 8.13 volt getting only around 5000mah.

Trying to charge using the regular charger did not work ...
So i tried charging using my accucel and after only 3500mah, the cell inflated.

Hi cry

You have just confirmed our worst fears here !! Over in that country they just put whatever they like on the label. Thanks for that investigation hmm

I guess the original cells are OK but of a lower capacity however the ebay resellers just inflate the claims in a bidding war to sound like the best !! confuse

Jaahn

-- Edited by Jaahn on Thursday 12th of November 2015 10:10:03 AM

JackoFJR · Senior Member

A update , l got my Mini Jump Starter back off the mate today . We have a old EL Falcon 4Lt petrol motor , l turned on the Head Lights , Fan and Radio , flattened the Batt dead flat , turn the key nothing .

My Jump Starter claims 13800mAh - start current 300A - peak 600A .

I started the Falcon 12 times , cranked it a few times with the head light on between starts with the Jump Pack disconnect to make sure the Batt stayed dead flat ,

The Jump Starter claims to have 30 starts before it needs charging , l stopped playing at 12 , it still showed full charge .

jonathan · Veteran Member

I've got one of these super mini boosters .. quite a remarkable little unit and very handy.

I will say that so far I haven't needed to use it to kickstart anything, but it makes a great portable power supply when away from normal power sources ..

http://www.threewayworks.com.au/superminibooster-2/

erad · Guru

I had an old style jump starter - one with a small compressor in it as well. Great device until I needed it one day for the guy next door. Dead as a dodo. I have carried it around Oz twice, hoping I wouldn't need it (and didn't). I took the battery out of it and checked it - no way would it take charge. I looked at getting another jump starter, but ultimately I went to the
local Battery World place (fantastic service from this guy) and bought a new battery. It was 12V and 24 AH. It was the largest battery which would fit in the casing.

The big issue with all these things is that they must be charged and kept charged. Even then, they may not work when you need them, but at least you have tried. Generally all you need to do is to top up the charge in your main battery - you rarely start the engine directly off the jump starter. So you probably only need 50 amps for maybe a minute and you hopefulyl will have enough in the main battery to start the engine. Then you must remember to recharge the jump starter again...

JackoFJR · Senior Member

Like anything with a battery that you don't use very often , if you just throw it in the boot and forget about it chances it will be flat when you need it .
Just today I gave my sat Phone a charge ,

mjt57 · Senior Member

Thinking about keeping these charge packs in the boot, most these days have a power outlet. I'd probably leave the battery pack connected to it. That is, if they're designed to maintain a charge this way.