Overclocker
10 kW
ford ecosport 1.5 liter gasoline
how many amps do i need to start this?
i'm thinking Sony VTC5A or the cheaper LG HB6
18650 pack to jump start a small car...
- Thread starter Overclocker
- Start date
ford ecosport 1.5 liter gasoline
how many amps do i need to start this?
i'm thinking Sony VTC5A or the cheaper LG HB6
Whatever the best price is on HB2/HB4/HB6.
They are only 1500-mAh each, but....you only need them to do their thing for about three seconds. 4S / 4P, 16 cells.
Maybe use pressure contacts with thick copper strips? Recharge them all in 1P at 4.1v?
They are only 1500-mAh each, but....you only need them to do their thing for about three seconds. 4S / 4P, 16 cells.
Maybe use pressure contacts with thick copper strips? Recharge them all in 1P at 4.1v?
Icewrench
10 kW
Large old American V-8`s can take up to 200 plus amps to get the motor turning and @ 100 plus amps to keep it rolling over.
Starters work best when sag does not go below 10 volts.
Starters work best when sag does not go below 10 volts.
rojitor
100 kW
Why not supercapacitors?
Super-capacitors would cost more, but...they are absolutely the appropriate tech for starting a car. I have read that Russians and Canadians sometimes use supercaps, due to severely cold winters.
https://www.youtube.com/watch?v=9y4pwcFyLOE
[youtube]9y4pwcFyLOE[/youtube]
https://www.youtube.com/watch?v=9y4pwcFyLOE
[youtube]9y4pwcFyLOE[/youtube]
skeetab5780
1 MW
Doctorbass did this years ago. The best booster pack to start a car is 4 or 8 26650 a123 lifepo4 cells in series 4s1p or 4s2p. Its incredibly small form and can take over 120a burst per cell
HB6 has been tested by quite a few reviewers. Can provide 40A, but will get too hot if you draw that amount for any length of time. At 30A continuous it reaches 77C (170F), but...for a 3 second burst to start a car, a 16-cell pack will never reach these temps. They are $5 each right now.
To buy 16 of them is $80 plus tax and shipping. 4P can produce 160A to get the engine started turning, and 120A continuous to keep it spinning (and it would likely draw 80A or less at that point). How many seconds does it take to start your car?
https://www.e-cigarette-forum.com/f...antastic-30a-battery-but-low-capacity.714450/
To buy 16 of them is $80 plus tax and shipping. 4P can produce 160A to get the engine started turning, and 120A continuous to keep it spinning (and it would likely draw 80A or less at that point). How many seconds does it take to start your car?
https://www.e-cigarette-forum.com/f...antastic-30a-battery-but-low-capacity.714450/
That's a good point, I don't know. Probably best to start with 3S / 4P and see how it goes.
Fully charged lead-acid is around 13V, so I would guess that it can't turn over a car at 11V? I'd suggest that it would be best to disconnect the lead-acid battery to start the car, then reconnect after it is running.
In this application, a fully charged 4.1V set of cells will be 12.3V at 3S, so...why not? If 3S works, no need to buy those other 4 cells.
The pack would now be 3S / 4P for 12 cells, $60 plus T&S. Or...you could add another P-string to make up for the lower volts, 3S / 5P for 15 cells? $75?
Fully charged lead-acid is around 13V, so I would guess that it can't turn over a car at 11V? I'd suggest that it would be best to disconnect the lead-acid battery to start the car, then reconnect after it is running.
In this application, a fully charged 4.1V set of cells will be 12.3V at 3S, so...why not? If 3S works, no need to buy those other 4 cells.
The pack would now be 3S / 4P for 12 cells, $60 plus T&S. Or...you could add another P-string to make up for the lower volts, 3S / 5P for 15 cells? $75?
maydaverave
10 kW
- Joined
- Jan 13, 2009
- Messages
- 542
They sell super capacitor packs to be installed parallel with your lead acid battery for cold weather and just generally save your battery and have more powerful faster starts.
http://www.amazon.com/gp/aw/d/B00PU4J7GY/ref=ya_aw_oh_bia_dp?ie=UTF8&psc=1
http://www.amazon.com/gp/aw/d/B00PU4J7GY/ref=ya_aw_oh_bia_dp?ie=UTF8&psc=1
Rassy
1 MW
I know this thread is about a DIY jump starter, but, I recently purchased a beatit product on Amazon and had occasion to use it last Friday:
https://www.amazon.com/10800mAh-Portable-Starter-Battery-Booster/dp/B01MXQCZAP
It cost $39.99 shipped. Claims it's capable of producing 500A at 12V, and a capacity of 10.8AH/39.96WH. It weighs less than a pound.
I think their AH claim is at the cell size of 3.7V, so the 10.8AH is probably 4 times larger than the 12v+ AH.
Anyway, I left the key in at accessory mode after opening all the windows on a hot afternoon. When I discovered this the battery was dead, showing 6 volts. It's a 2012 Honda CRV with a 2.4 liter engine, and with the little Beatit Booster it started right up. Sounded close to normal while cranking, but the car has always started easy and it only took 2 or 3 seconds.
When I put the unit on a charger it still showed 3/4 charge, and took about 1 hour to charge up. Wasn't home and don't know how much juice was used during the recharge.
Nice things about the kit it includes an adequate set of battery clamps for starting, a multi connection cable that is used to connect the clamps for starting and also can be used to charge a phone or camera, etc., and it recharges directly from a USB wall wart. My car came with a USB outlet wired in the center console so after using the unit you can be charging it while you drive.
https://www.amazon.com/10800mAh-Portable-Starter-Battery-Booster/dp/B01MXQCZAP
It cost $39.99 shipped. Claims it's capable of producing 500A at 12V, and a capacity of 10.8AH/39.96WH. It weighs less than a pound.
I think their AH claim is at the cell size of 3.7V, so the 10.8AH is probably 4 times larger than the 12v+ AH.
Anyway, I left the key in at accessory mode after opening all the windows on a hot afternoon. When I discovered this the battery was dead, showing 6 volts. It's a 2012 Honda CRV with a 2.4 liter engine, and with the little Beatit Booster it started right up. Sounded close to normal while cranking, but the car has always started easy and it only took 2 or 3 seconds.
When I put the unit on a charger it still showed 3/4 charge, and took about 1 hour to charge up. Wasn't home and don't know how much juice was used during the recharge.
Nice things about the kit it includes an adequate set of battery clamps for starting, a multi connection cable that is used to connect the clamps for starting and also can be used to charge a phone or camera, etc., and it recharges directly from a USB wall wart. My car came with a USB outlet wired in the center console so after using the unit you can be charging it while you drive.
skeetab5780
1 MW
This is the problem with lithium ion 3.7 nominal cells and 12v applications its easier to use 3.2v lifepo4 since 3 cell is not enough and four cells is too much voltage for the systems. But with lifepo4 4s is perfect.minimum said:
Problem with 3.7 18650 is 3s voltage will be to low for the system and you will need twice the watthours to make up for the sag
Hillhater
100 TW
Talk about re-inventing the wheel !..
How many times does this topic come up ?,..why dont folk use the search function.
Most of the commercial "glovebox jump starters" use 3S lipo pouches...Hobbyking even sell one specifically for this.
But if you want to build your own , go for the 3S, 100C , Nanotech RC pack.
How many times does this topic come up ?,..why dont folk use the search function.
Most of the commercial "glovebox jump starters" use 3S lipo pouches...Hobbyking even sell one specifically for this.
But if you want to build your own , go for the 3S, 100C , Nanotech RC pack.
There's a search function? OMG I had no idea.... :lol:Hillhater said:
https://endless-sphere.com/forums/search.php?keywords=jump*+start*&terms=all&author=&sc=1&sf=titleonly&sk=t&sd=d&sr=topics&st=0&ch=300&t=0&submit=Search
https://endless-sphere.com/forums/search.php?keywords=starter+pack&terms=all&author=&sc=1&sf=titleonly&sk=t&sd=d&sr=topics&st=0&ch=300&t=0&submit=Search
Less relevant stuff but some
https://endless-sphere.com/forums/search.php?keywords=car+battery&terms=all&author=&sc=1&sf=titleonly&sk=t&sd=d&sr=topics&st=0&ch=300&t=0&submit=Search
The fingers
10 TW
It's that little box with the magnifying glass at the top right of the page. 
Overclocker
10 kW
haha actually my question is how many amps is needed to start this small 1.5L engine. that's all i need to know, i can deal w/ cell selection myself
think honda jazz engine, or hyundai accent
the objective is to use as few cells as possible
think honda jazz engine, or hyundai accent
the objective is to use as few cells as possible
Icewrench
10 kW
Well here in my shop the only 4 banger is a 87 Camry 2.0. Surprisingly it takes near 200 amps to start turning over and a bit over 100 amps to keep it spinning.
skeetab5780
1 MW
Icewrench said:
and then when its 20 degrees outside and frosty it could take another 50-75amps
If you absolutely MUST use 18650 cells for 200A/100A peak/continuous...using HB6 we are now up to 3S / 6P = 18 cells.
This might be a job for the DeWalt 21700 cells? Samsung 30T...60A/30A...3S / 4P, 12 cells...$7 each, $84?
This might be a job for the DeWalt 21700 cells? Samsung 30T...60A/30A...3S / 4P, 12 cells...$7 each, $84?
mistercrash
10 kW
Once I had to jump start my 2014 Mazda CX5. We were at the RC airplane club so I used one of my kid's Hobby King 2.2 Ah 40C 3S battery. Worked like a charm.
Sunder
10 MW
There is a big difference between jumping a car with no battery attached at all, and one whose battery is a little flat or just old.
The first needs a very high surge power for a very short time. The second just needs to provide ~14v for 30 seconds to give the lead acid battery a surface charge. In other words, the dead lead acid becomes somewhat of the world's worst capacitor...
Don't know if you really want something slick that works in all circumstances, or something basic that will bail you out 90% of the time, but the bar is really lowered if its the latter.
The first needs a very high surge power for a very short time. The second just needs to provide ~14v for 30 seconds to give the lead acid battery a surface charge. In other words, the dead lead acid becomes somewhat of the world's worst capacitor...
Don't know if you really want something slick that works in all circumstances, or something basic that will bail you out 90% of the time, but the bar is really lowered if its the latter.
Sunder
10 MW
By the way, the three things that contribute to cold cranking amps requirement are:
1. Mass of the rotating parts - crankshaft, conrods, pistons, camshafts, valves, etc. A minor contributor to this will be valve spring strength, and cam duration.
2. Compression of the motor - a 8:1 motor is going to be easier to turn than an 11:1 motor
3. Accessories attached to the crank. Power steer, air conditioning, fan belts, etc, are all going to make it harder to crank
All that said, it looks like the CCA of the original battery was 240ish Amps, by IEC standards, higher by SAE standards. You probably don't need that much power for a single start, because there's always buffer to ensure long battery life.
1. Mass of the rotating parts - crankshaft, conrods, pistons, camshafts, valves, etc. A minor contributor to this will be valve spring strength, and cam duration.
2. Compression of the motor - a 8:1 motor is going to be easier to turn than an 11:1 motor
3. Accessories attached to the crank. Power steer, air conditioning, fan belts, etc, are all going to make it harder to crank
All that said, it looks like the CCA of the original battery was 240ish Amps, by IEC standards, higher by SAE standards. You probably don't need that much power for a single start, because there's always buffer to ensure long battery life.
Hillhater
100 TW
True, but also beware if the main battery has died from an internal failure (common) ..Sunder said:
Open circuit fail is not a problem, but some fail and short a cell internally , which can pull down any voltage from the jumper pack and prevent a restart.
You may need to disconnect the main battery in that case.
I have found that a 4 year old lead starter battery is past its use by date and should be replaced before it lets you down somewhere you do not want to be, or at a time you cannot afford to be delayed ..
...cheap insurance.!..... For the price of a decent meal.
okashira
10 kW
Started a 5L V8 with a 7p4s pack of Tesla cells (no lead acid - disconnected) easily....
Food must be much more expensive down there...or you have more expensive standards than I do.Hillhater said:
