Got a question about Peltier TEG’s – Are they going to give me enough power for my racing car?

I’m adding some more electrical gear to the engine on the car, and in years past it’s just run on a plain battery with no generator/alternator to charge it up again. Since it only runs for about ten minutes or so at a time it’s never been a problem. But I’m adding computer control to the ignition system and also an electric water pump (Davies Craig Aussie unit) and I want to look at various options to make a bit of power somehow.
There’s no room to fit even a small alternator anywhere. The engine won’t have the distributor sticking out of the back of the head any more – See the ignition leads at the back of the head in this photo –

- So I thought about fitting a small electric motor in that hole to make it work as a generator. It’d be doing a maximum of 4,000 rpm and get down as low as about 2,500 rpm at times. (Half engine speed) I tried a couple of spare brushed electric motors I have here and at full speed in my drill, about 1,700 rpm, they made a less-than-stellar 0.5 volts and naff-all amps.
Plan B with that was to try a brushless electric motor & rectifier as there are one available that should be able to make reasonable power. One of the ratings they use for them is something like 200 kv, which means that for 1 volt the motor will do 200 rpm. They also come with much higher kv’s, but that of course means that they need a heap of revs up to make power. So the lower kv engines are the types needed. E.g. – https://hobbyking.com/en_us/kd-53-30-high-voltage-brushless-outrunner-190kv.html
I was after any opinions if this is likely to be able to make the 13 volts & about 10 amps that I’d like?

Another possibility was to use Peltier TEG units. There’s plenty of heat around the edges of the radiator – The water will run at about 80° C and the airflow around it would be between 25° to about 35°, so a reasonable temperature differential. There’s also the option of putting them near the exhaust pipes, which is rather hot. I can also organise cooling air for the other side of the Peltiers in that case.
When searching for those units, one type seems to be the most common, a 40 mm x 40 mm type. E.G – Like this one

Is the Peltier system going to be even remotely close to the 13 volts & ~ 10 amps I’m after? Is it as simple as adding them in parallel & series to get that amount of power?

Bill, where the electric motors you tried permanent magnet motors?

Spiny Norman said:

Got a question about Peltier TEG’s – Are they going to give me enough power for my racing car?

I’m adding some more electrical gear to the engine on the car, and in years past it’s just run on a plain battery with no generator/alternator to charge it up again. Since it only runs for about ten minutes or so at a time it’s never been a problem. But I’m adding computer control to the ignition system and also an electric water pump (Davies Craig Aussie unit) and I want to look at various options to make a bit of power somehow.
There’s no room to fit even a small alternator anywhere. The engine won’t have the distributor sticking out of the back of the head any more – See the ignition leads at the back of the head in this photo –

- So I thought about fitting a small electric motor in that hole to make it work as a generator. It’d be doing a maximum of 4,000 rpm and get down as low as about 2,500 rpm at times. (Half engine speed) I tried a couple of spare brushed electric motors I have here and at full speed in my drill, about 1,700 rpm, they made a less-than-stellar 0.5 volts and naff-all amps.
Plan B with that was to try a brushless electric motor & rectifier as there are one available that should be able to make reasonable power. One of the ratings they use for them is something like 200 kv, which means that for 1 volt the motor will do 200 rpm. They also come with much higher kv’s, but that of course means that they need a heap of revs up to make power. So the lower kv engines are the types needed. E.g. – https://hobbyking.com/en_us/kd-53-30-high-voltage-brushless-outrunner-190kv.html
I was after any opinions if this is likely to be able to make the 13 volts & about 10 amps that I’d like?

Another possibility was to use Peltier TEG units. There’s plenty of heat around the edges of the radiator – The water will run at about 80° C and the airflow around it would be between 25° to about 35°, so a reasonable temperature differential. There’s also the option of putting them near the exhaust pipes, which is rather hot. I can also organise cooling air for the other side of the Peltiers in that case.
When searching for those units, one type seems to be the most common, a 40 mm x 40 mm type. E.G – Like this one

Is the Peltier system going to be even remotely close to the 13 volts & ~ 10 amps I’m after? Is it as simple as adding them in parallel & series to get that amount of power?

My knowledge of all this is exceedingly limited.

From https://en.wikipedia.org/wiki/Automotive_thermoelectric_generator :

“With exhaust temperatures of 700 °C or more, the temperature difference between exhaust gas on the hot side and coolant on the cold side is capable of generating 500-750 W of electricity.”

13 volts at ~ 10 amps is about 130 watts, which is less than 500-700 watts. Is that a help?

Looking up some specs for the Peltier or Seebek device that you’ve shown and you get:

40 degree temperature difference: open circuit voltage 1.8V, generated current: 368MA.

Cannot see anything about loaded voltage so take a SWAG and say around 1.5 volts. So we need 9 in series to get up to the voltage .

To get to the required amperage you’re going to need thirty (30) in parallel. So the 9 in series by the 30 in parallel means 270 of these devices.

That’s only 0.43 m² of room required (680mm x 680mm), I’m certain you’ll fit that in.

I’ll add in further specs if you want to do some further cals.

60 degree temperature difference: open circuit voltage 2.4V, generated current: 469MA

80 degree temperature difference: the open circuit voltage 3.6V, generated current: 558MA

100 degree temperature difference: open circuit voltage 4.8V, generated current: 669MA

mollwollfumble said:

13 volts at ~ 10 amps is about 130 watts, which is less than 500-700 watts. Is that a help?

Yes, thanks – Though Mr Been’s answer helps solve it for me.

sibeen said:

Looking up some specs for the Peltier or Seebek device that you’ve shown and you get:

40 degree temperature difference: open circuit voltage 1.8V, generated current: 368MA.

Cannot see anything about loaded voltage so take a SWAG and say around 1.5 volts. So we need 9 in series to get up to the voltage .

To get to the required amperage you’re going to need thirty (30) in parallel. So the 9 in series by the 30 in parallel means 270 of these devices.

That’s only 0.43 m² of room required (680mm x 680mm), I’m certain you’ll fit that in.

It’s only a small car so that would be a bit of a problem. It’d be easier to just fit a larger battery.

sibeen said:

Bill, where the electric motors you tried permanent magnet motors?

Yep, this one.

you could have a small turbine that just spins around in the wind – presumably your stationary time in a race would be close to zero???

wookiemeister said:

you could have a small turbine that just spins around in the wind – presumably your stationary time in a race would be close to zero???

Too much drag, and yes when it’s racing the car is going fairly quickly – Around Lakeside the average speed for me is about 160 km/h.

Spiny Norman said:

wookiemeister said:

you could have a small turbine that just spins around in the wind – presumably your stationary time in a race would be close to zero???

Too much drag, and yes when it’s racing the car is going fairly quickly – Around Lakeside the average speed for me is about 160 km/h.

solar panels?

large capacity lithium battery ?

wookiemeister said:

solar panels?

Not enough area to really make one work. And to reply to your other post, yeah I reckon I’ll just fit a larger battery and be done with it.

wookiemeister said:

Around Lakeside the average speed for me is about 160 km/h.

Can’t get much peltier than that

Spiny Norman said:

wookiemeister said:

solar panels?

Not enough area to really make one work. And to reply to your other post, yeah I reckon I’ll just fit a larger battery and be done with it.

There is a little comment on wikipedia to the effect that Peltier devices for energy generation would have to have a higher energy density to be competitive. So yes, wikipedia agrees with you.

Spiny Norman said:

wookiemeister said:

you could have a small turbine that just spins around in the wind – presumably your stationary time in a race would be close to zero???

Too much drag, and yes when it’s racing the car is going fairly quickly – Around Lakeside the average speed for me is about 160 km/h.

Agree, too much drag.