Replace your car battery with capacitors!

[Ecky]

Originally Posted by redpoint5

The balance boards I've seen all show them paired between 2 caps on a single "end". I've got 5 caps, so I wonder if I can put balance boards on both ends as if I'm creating a series circuit? In other words, 4 balance boards for 5 capacitors.

I might buy another cap so I'm not pushing voltage so close to limits.

I'm thinking of selling my 6x 3000F cap bank, if anyone here is interested.


~

EDIT: I settled on a 66F (6x 400F) cap pack paired with a 20Ah LiFePO4 in the summer, and caps + an AGM in the winter. The 500F pack above easily starts the car year round, but it's very easy to drain it sitting for even a few minutes with lights on, or if you have to crank 2-3 times. I'd definitely keep a small battery around, regardless of what you use.

[redpoint5]

Our Allis Chalmers One Ninety uses 2x group 31 batteries with 1,800 CCA to start the diesel motor. Usually the batteries are too abused to start the tractor.

I wonder if a cap bank would be enough to start... it wasn't enough to start my Cummins 5.9L engine.

I might be interested in purchasing the 3000 farad bank if the price were right, but I have no immediate need for them.

[serialk11r]

Originally Posted by redpoint5

Our Allis Chalmers One Ninety uses 2x group 31 batteries with 1,800 CCA to start the diesel motor. Usually the batteries are too abused to start the tractor.

I wonder if a cap bank would be enough to start... it wasn't enough to start my Cummins 5.9L engine.

I might be interested in purchasing the 3000 farad bank if the price were right, but I have no immediate need for them.

Is this enough? https://www.ebay.com/itm/Maxwell-Nes...IAAOSwk5pfMyZ3

In 6S3P that would be 1500 farads, 120kJ. Almost a third of the KERS limit for a lap in F1 IIRC

[redpoint5]

I'll give my existing bank a shot. It's been years since we fired her up since my dad got a medium sized John Deere for around the house. That AC is really only useful for field sized projects, or picking cherries from the tops of trees from the bucket.

We've got a dozer in the front yard (redneck cred) that hasn't started in a decade. It has a gasoline engine (pony motor) you start with a battery, which then starts the diesel engine.

[serialk11r]

Just found this:
https://www.aliexpress.com/item/1005...archweb201603_

28 shipped (probably will go up a few bucks someday when ePacket gets more expensive) for the shrink wrapped with leads version. Should be enough to start any car engine when fully charged.

[redpoint5]

Originally Posted by serialk11r

Just found this:
https://www.aliexpress.com/item/1005...archweb201603_

28 shipped (probably will go up a few bucks someday when ePacket gets more expensive) for the shrink wrapped with leads version. Should be enough to start any car engine when fully charged.

I wonder if there is any balance circuitry? The product description said it lasts 5-10 years, which seems rather short.

[teoman]

Originally Posted by redpoint5

I wonder if there is any balance circuitry? The product description said it lasts 5-10 years, which seems rather short.

I have that,

The caps are very mismatched. When charged up, some can be at 2.3 while others at 2.7. And the balancing function does not work too well either.


Looks the same, i had bought it a long time ago, so not sure if really identical product.

[serialk11r]

If you click the different options they have (you can the bare board with no wires or case), it seems to be LED/regulator balanced (aka very low current), so it wouldn't be surprising to see them go quite out of balance.

10 years is what Maxwell states for their capacitor lifespan. Could be better, but it's not much money.

[serialk11r]

I just got my hall effect ammeter in the mail today, so I went to the old Honda Pilot (3.5L V6) and tried it out. Temperature was probably around 60F, so a fairly easy start. Obviously, cranking is pretty quick and I only have a crappy multimeter so I may have missed the peak of the voltage spike, but the highest number I saw was 233A, the next number that flashed was something like 178, and then maybe like 90?. Maybe we can call it...300 peak?

The little 100F capacitors have a series resistance of 12mohm, so at 300A we're looking at a 3.6V drop (yikes!). Actually, if you're starting at 11V, that lands you at 7.4V, which is still above the "cold cranking" procedure minimum. We have around 5-6 coloumbs of charge before we're down to 9V, which isn't much.

Multiply the capacity by 5 however, and we're in business. The 500F caps would be able to push out 300A without breaking a sweat, and we would have several hundred usable joules for cranking.

[njlou]

great concept!! maybe a compromise of a small battery and some caps, like some of the start packs.