Any Experiences With Supercapacitor Jump Starters?

[easysurfer]

I have one of those old fashioned lead acid battery type jump starters that need top off charging about once every 2 months to keep alive.

The one I have is over 10 years old, still works like new as long as I top off charge. Have used it successfully for a couple of jump starts in the past.

Yesterday, I stumbled upon on youtube something called a supercapacitor jump starter. I guess they are nothing new (just newer) than the old fashioned jumpers. Seems like the supercapacitor type offer some nice advantages such as not having to recharge a battery (it doesn't use batteries), safer and simple (just connect pos to pos, neg to neg), portability, not weather sensitive.

When you find yourself on the side of the road or in a parking lot with a dead battery, having a jump pack at the ready can come in handy. While everyday battery-powered jump packs may work great, they require lengthy charge times to remain powered up, and they’re big and bulky. Today’s batteryless options offer the same power to start your vehicle in a substantially smaller package.

http://knowhow.napaonline.com/batteryless-jump-starter-pint-sized-power-packs-punch/

 

[JRon]

Saw this post, but had never heard of these before. Did a little reading and it appears they’re legit. They charge using the remaining power left in the battery and then give you a 5 - 10 second power surge to start the vehicle. Very interesting.

 

[easysurfer]

Saw this post, but had never heard of these before. Did a little reading and it appears they’re legit. They charge using the remaining power left in the battery and then give you a 5 - 10 second power surge to start the vehicle. Very interesting.

I hadn't heard of these before either until yesterday. I think very interesting too.

 

[ERD50]

Interesting, but color me skeptical ( I don't understand 'simpler'? Isn't that the same as any portable charger?)

A battery provides all its rated energy over a limited voltage range, ~ 10.2 to ~14 Volts for a lead acid, and Lithium batteries will be series connected for a similar range.

But a capacitor has to go from full voltage to zero volts to deliver all its energy. So if you slow charge off a 12.5 volt low battery, they can really only provide power from that 12.5 V down to maybe ~ 9 V (the point that the starter probably won't kick in). You just can't access ~75% of that energy w/o a voltage converter, but those would be very big $ at the hundreds of amps a car starter needs.

The concept is sound in some ways - those super caps can deliver very high currents for starting, and I can see where you could trickle charge it from a marginal battery for a few minutes and then deliver a short burst of high current for the starter. As an example, draw 2 amps for 300 seconds (5 minutes), and it could deliver 300 starting amps for 2 seconds. But you will need a lots of Farads to crank a starter for more than a few seconds.

Lets see, C = (t * i)/(delta V)

(2*300)/3 = 200 Farads. And Super Caps are low voltage ( ~ 2.5V), so you need ~ 6 in series, which reduces the total capacitance, so 6 x 1200 Farads, ~ 7200 Farads of Super Caps. I don't think you can get that many F into a $100 charger, I'd like to see the detailed specs.

EDIT/ADD: OK, I realize they *can* us a voltage converter to charge the caps. That's a lower current over a longer time, so a battery sitting at even 11.5V could be used to convert and charge those caps up to 14 V, which would help a lot.


-ERD50

 

[Pacinotti]

https://youtu.be/JN8A2nIMUWA

Tested here. Among the worst.

 

[easysurfer]

https://youtu.be/JN8A2nIMUWA

Tested here. Among the worst.

That was a pretty rough testing with most of the jumpers failing. Even the lead acid type jumper failed.

I wonder had he testing on a car instead of tractor how well they would've performed.

I'm surprised that the GB40 performed so poorly also as that seems like a popular brand.

 

[ERD50]

https://youtu.be/JN8A2nIMUWA

Tested here. Among the worst.

Thanks for the link. I was thinking I may have been overly skeptical, but these tests seem to match my rough estimates. If you jump to ~ 10:14 in that video (this link should take you there):

https://youtu.be/JN8A2nIMUWA?t=614

You'll see he uses it to turn over a truck with a battery discharged to ~ 7.5V. The truck is a 2.9L, so a fairly typical engine size. He is in short sleeves, so I assume this is ~ room temperature, and the Super Cap model can only turn the engine for ~ 2 seconds after a full charge from that battery (which took 15 minutes). That should get you started under good conditions.

But if it were cold out, I doubt that thing could crank it long enough. The better units among the competition cranked for 7~8 seconds, which I think might also be marginal in cold weather. I'm not ditching my jumper cables.

-ERD50

 

[ERD50]

That was a pretty rough testing ...

IMO, rough testing would be turning an engine over at -10F.

If you live in a place with cold winters, if you can't count on that thing, you need it and a pair of jumpers. So what's the point?

edit: OK, it *might* get you going charged from the mostly dead battery, and you won't need a second vehicle to jump from. Still seems marginal to me.

-ERD50

 

[sengsational]

If they were all that great, one might expect a vehicle manufacturer to build it into the vehicle. I'll admit to knowing nothing about them, including how big they are, but in principle, a capacitor shouldn't wear out, so would last as long as other components.

 

[easysurfer]

In the comparison tests of that video, I would have liked to seen a top of the line lead acid type model jumper included in the test instead of the Black and Decker. If I was looking for a reliable jump starter, Black and Decker would not be my first choice.

Regardless of brand, I'd want one that's reliable and can start if I mistakenly left the lights on overnight and barely get at click in the morning.

Whether one works in very extreme conditions, that varies with individuals' driving environments.

Similar to when I got in impact wrench to remove lug nuts in case of a flat. I don't want one that may or may not work (not much use if I'm stranded somewhere and fails). I want one that's gets the job done without worry.

 

[nap470]

Last winter I purchased a Schumacher brand (at Wal-Mart) of these handheld jump starters at the urging of my wife prior to one of our road trips to visit our daughter at college. Surprisingly, the next week I had a chance to use it at our local dog park when a lady's car would not start. It was about 15 degrees if I remember correctly. Amazingly, it started her car right away. It was a Toyota Corolla and she was so thrilled that I'm sure she went and purchased one immediately. It may have been pure coincidence that the car started. I have not used it since. Actually this posting has reminded me to get it out of DW's car and charge it up. Storing in cold temperatures seems to reduce the charge rather quickly.

 

[easysurfer]

Last winter I purchased a Schumacher brand (at Wal-Mart) of these handheld jump starters at the urging of my wife prior to one of our road trips to visit our daughter at college. Surprisingly, the next week I had a chance to use it at our local dog park when a lady's car would not start. It was about 15 degrees if I remember correctly. Amazingly, it started her car right away. It was a Toyota Corolla and she was so thrilled that I'm sure she went and purchased one immediately. It may have been pure coincidence that the car started. I have not used it since. Actually this posting has reminded me to get it out of DW's car and charge it up. Storing in cold temperatures seems to reduce the charge rather quickly.

This posting reminded me I need to take my car out for a drive since it's been sitting in the garage for almost a month. I do have a tester for the battery that shows state of health 89%, state of charge (about, can't remember exact) 45% - recharge.

 

[sengsational]

... I don't want one that may or may not work (not much use if I'm stranded somewhere and fails). I want one that's gets the job done without worry.

Right. It's a less robust solution if it depends on a less than completely dead battery. Maybe they need one with a crank that allows you to exchange mechanical energy to get the plates charged.

 

[Sunset]

Last winter I purchased a Schumacher brand (at Wal-Mart) of these handheld jump starters at the urging of my wife prior to one of our road trips to visit our daughter at college. Surprisingly, the next week I had a chance to use it at our local dog park when a lady's car would not start. It was about 15 degrees if I remember correctly. Amazingly, it started her car right away. It was a Toyota Corolla and she was so thrilled that I'm sure she went and purchased one immediately. It may have been pure coincidence that the car started. I have not used it since. Actually this posting has reminded me to get it out of DW's car and charge it up. Storing in cold temperatures seems to reduce the charge rather quickly.

I wonder if the battery just reads a lower charge when cold, and if you let it warm up, that it would show a higher charge.

 

[ERD50]

If they were all that great, one might expect a vehicle manufacturer to build it into the vehicle. I'll admit to knowing nothing about them, including how big they are, but in principle, a capacitor shouldn't wear out, so would last as long as other components.

About a year ago, I watched some youtube videos of a guy who was trying to replace his lead-acid starter battery with a super-cap array.

He lived in a hot climate, and heat is tough on lead-acid batteries. So his goal was not to have to replace his battery every couple years.

IIRC, his super-cap solution worked pretty well for him, but it couldn't supply the drain current over the course of a day or two (again, super-caps are great at short bursts of current, but it takes a LOT of them to store a lot of energy). He ended up adding a motorcycle battery in parallel, which supplied the drain currents, and the super-caps handled the starting current.

I think he decided the cost difference of a motorcycle battery plus super-cap wasn't a great trade off. But it did work.

Some numbers... 200 Amps for 2 seconds is 400 amp-seconds (seems modern cars start almost instantly in warm weather, so even 2 seconds is probably much longer than typical), and that's 0.111 Amp-Hours (111 mAh). And that would be just 5 Milli-amps over a 24 hour period, and I think many cars are in the 20~30 Mill-amp range for drain current ( ~600 mAh to work backwards again) . So a day of idle time takes ~ 5 times more energy than a start does.

-ERD50

 

[Music Lover]

You'll see he uses it to turn over a truck with a battery discharged to ~ 7.5V. The truck is a 2.9L, so a fairly typical engine size. He is in short sleeves, so I assume this is ~ room temperature, and the Super Cap model can only turn the engine for ~ 2 seconds after a full charge from that battery (which took 15 minutes). That should get you started under good conditions.

But if it were cold out, I doubt that thing could crank it long enough. The better units among the competition cranked for 7~8 seconds, which I think might also be marginal in cold weather. I'm not ditching my jumper cables.

-ERD50

That's a deal breaker for me...it gets to -35 here and I have no interest waiting 15 minutes and then hoping it will start. The portable jump starters are small and some come with an LED light and a phone charger. I can't think of any reason to switch but plenty of reasons not to.

 

[GTFan]

Yeah I'm also not seeing the issue with current lithium starters, they're small enough and hold a charge a long time. It's not like they're a problem vs. a supercap that may or may not work.

Plus they can be used as temp power banks for phones etc. if your power goes out.

 

[easysurfer]

Here is a review of the super capacitor jump starter. Looks like that jumper (there are other supercaps out there) was a Kickstarter project from summer last year.

A fair review I think. Somewhere in the middle between yay or nay.

Jumpstarting a car is always a pain, mostly because it means you’ll be late reaching your destination. Just how late, of course, depends on the method you use; jumper cables are a cheap, but time-consuming hassle that require a second vehicle. Jump boxes—basically portable batteries—can cut the second car out of the equation, saving time, but cost significantly more, take up extra space in your trunk, and are often just as cumbersome as cables. If there were a way to jumpstart a car with less unwieldy equipment, it’d be worth looking into, hence our decision to test out an Autowit Supercap 2.

https://www.carnewscafe.com/2020/04/gadget-review-autowit-supercap-2-jump-starter/

 

[Music Lover]

That article claims that jump boxes need to be plugged in once a week...that's false. If they're not used the battery doesn't run down anywhere near that fast. And the "inconvenience" of charging it up for a few hours? Really?

 

[easysurfer]

That article claims that jump boxes need to be plugged in once a week...that's false. If they're not used the battery doesn't run down anywhere near that fast. And the "inconvenience" of charging it up for a few hours? Really?

Maybe my old eyes are failing me, but I don't see in the article where he says that jump boxes need to be plugged in once a week. He does say for hours which is incomplete because he doesn't say hours per what?

In my jump box experience, when not used, I plug the jump box and recharge overnight about once every two months. Also, if used then I recharge overnight.

I see the supercap jumper as maybe handy for a quick try to jump. But still probably want to have a more able jumper just in case. So begs the question is it more a luxury or just something extra to deal with?

I've got recharging my jump starter every 2 months down to a habit so really isn't much of an inconvenience. Going on over 10 years, works like new .

 

[Music Lover]

Maybe my old eyes are failing me, but I don't see in the article where he says that jump boxes need to be plugged in once a week. He does say for hours which is incomplete because he doesn't say hours per what?

In my jump box experience, when not used, I plug the jump box and recharge overnight about once every two months. Also, if used then I recharge overnight.

I see the supercap jumper as maybe handy for a quick try to jump. But still probably want to have a more able jumper just in case. So begs the question is it more a luxury or just something extra to deal with?

I've got recharging my jump starter every 2 months down to a habit so really isn't much of an inconvenience. Going on over 10 years, works like new .

I guess it's an inconvenience charging if you need it right now, but the initial charge and maybe topping it up every few months just to be safe isn't really an inconvenience. It's no different than charging a cell phone...you plug it in at a convenient time and come back later.

I got the impression he was saying they needed to be charged weekly from this sentence:

"But if you need the simplest solution to a car that won’t start, buying the cheapest traditional jump box you can find still strikes us as the pennywise option—even if it comes with the inconvenience of plugging it in weekly."

But maybe there are real cheap ones that need to be charged more often?

 

[ncbill]

I'd just buy a lithium battery jump starter...from personal experience they're good to go even after sitting in the vehicle for a few months.

 

[ERD50]

... A fair review I think. ...

I'll leave "fair" or "unfair" to the eye of the beholder, but I'd say it is a poorly done review.



emphasis mine

.... jumper cables are a cheap, but time-consuming hassle that require a second vehicle. ....

we hooked the Supercap 2 up directly to the battery as suggested, and the gadget indeed began to charge itself off the discharged battery. Its charge percentage grew slowly off the bad battery, so to save some time, we switched it to a fully charged battery, and found it charged far more quickly.

So the described advantage of a jump box (battery or super-cap) is it can save time by not needing to get access to a second vehicle or wait for a service truck. But then what do they do? They charge it from a second vehicle, because it was charging up "slowly", and found it "charged far more quickly" from the good battery.

How about some frame of reference for "slowly" and "far more quickly"?

He also assumes you'd have to wait for a lithium jump box to charge, but the idea is that you keep it charged once a month or so, so it should be ready at any time (true, people will forget, but it probably still has significant charge left after 6 months or so?).

I haven't looked yet, but it sure seems the lithium battery packs could pull the same 'trick' of charging off a mostly dead battery with an internal voltage booster circuit. Yes, you can charge up Super Caps at a faster rate than batteries, but assuming your Lithium is fairly well topped off, it shouldn't take too long?

-ERD50

 

[easysurfer]

I guess it's an inconvenience charging if you need it right now, but the initial charge and maybe topping it up every few months just to be safe isn't really an inconvenience. It's no different than charging a cell phone...you plug it in at a convenient time and come back later.

I got the impression he was saying they needed to be charged weekly from this sentence:

"But if you need the simplest solution to a car that won’t start, buying the cheapest traditional jump box you can find still strikes us as the pennywise option—even if it comes with the inconvenience of plugging it in weekly."

But maybe there are real cheap ones that need to be charged more often?

You're right, he did mention weekly. My old tired eyes did fail me .

 

[GTFan]

I'd just buy a lithium battery jump starter...from personal experience they're good to go even after sitting in the vehicle for a few months.

My lithium starter is good to go after a year, I rarely charge it. Always shows full charge when I check it - I end up charging it as a precaution but I don't think it needs it. I used it once to start a friend's 6 liter V8 truck after it had been sitting in my car for many months and it handled it with no issue.

Really no need nowadays to look any further than these boxes.