Open Source Electric Supercharger

[neutron256]

Originally Posted by AN

Great ... can you share a link of the ebay item ... also ... I know you have gone through a few motors but in you opinion .. what is the best motor(s) to couple to this new find ?

I just want to start looking/reading on a possible setup.
Thanks

http://www.ebay.com/itm/Seadoo-super...vip=true&rt=nc

This is the one I bought, but there are lots of others. I just went for one of the cheapest I'm not sure what shape the wheel/housing will really be in but it should be good enough to build a test rig.

The biggest motor I currently have is the Turnigy Aquastar T20. That's probably going to be a good match. I was doing some looking on hobby king and I saw this http://hobbyking.com/hobbyking/store...m_Fan_5kw.html it's 5000W and 870Kv so in a 24V system it could run at an average speed of around 20K RPM, and assuming max charge of 28V you might get as much as 28K RPM.

[neutron256]

Originally Posted by rusty959

First of all, 60 farads will lose over 3V each second with the power levels we are looking at.

Furthermore, car audio caps usually have a max voltage of 18-20 volts, so you would only be able to use a single battery (12v) battery with that cap, else put them in series which halves the capacitance. So it would take 4 of those caps to get 30 farads on a 24v setup. 60F would need 8. Therein lies the big issue with running high voltages with caps.

If you look that cap is actually for 24V

[rusty959]

Originally Posted by neutron256

If you look that cap is actually for 24V

Solid point. I missed that, since I expected important info like that to be in specs.

Regardless, 5kw from that cap will still go quick.

[neutron256]

Originally Posted by rusty959

Solid point. I missed that, since I expected important info like that to be in specs.

Regardless, 5kw from that cap will still go quick.

Yeah I agree. I found a good calculator at one point which made it clear that caps alone won't do the job. But I will say running them in parallel with a battery bank is a whole different animal.

[stugray]

Originally Posted by neutron256

A lot of this could be solved by moving the power system to the trunk as some have with the Phantom ESC.

Or perhaps some of it can be tucked up inside the fenders above the fender liner.
I have never taken out a liner and looked, but I suspect a significant amount of space in there.

I heard about a twin turbo kit for a corvette that puts the turbos in the rear fenders....(with that much plumbing, I am guessing that an intercooler is not required :-)

[neutron256]

Originally Posted by stugray

Or perhaps some of it can be tucked up inside the fenders above the fender liner.
I have never taken out a liner and looked, but I suspect a significant amount of space in there.

I heard about a twin turbo kit for a corvette that puts the turbos in the rear fenders....(with that much plumbing, I am guessing that an intercooler is not required :-)

It's possible. The only reason I haven't gone the direction of putting the power system in the trunk is the complexity. Same issue if you were to tuck it into the fender. Fabricating mounts, and the work to actually install it is very time consuming.

I really want to design a system that someone could build with minimal custom fabrication. But for others interested in a more complex setup I encourage them.

[AN]

Originally Posted by rusty959

First of all, 60 farads will lose over 3V each second with the power levels we are looking at.

Actually no .. since it will be in parallel to the battery , its voltage will not drop a whole lot more than the battery ... as immediately charges itself from the battery. Those combo will not discharge quicker than the battery alone. The cap only increases the systems ability to provide high spikes in current demand ... which the 1.5 pack shows is a bottleneck for the Pb-Acid batteries for this scenario.

Originally Posted by rusty959

Furthermore, car audio caps usually have a max voltage of 18-20 volts, so you would only be able to use a single battery (12v) battery with that cap, else put them in series which halves the capacitance. So it would take 4 of those caps to get 30 farads on a 24v setup. 60F would need 8. Therein lies the big issue with running high voltages with caps.

We can find some caps that surge at 30V. Even if we have to put 2 caps in series ... the capacitance halves but energy storage doubles ... given twice the voltage ... we do not have to go huge on caps in the first go around ... I think 2x of the most compact caps with 10+ F in parallel should do the trick ... again .. not for primary energy delivery but to ease the most extreme loads on the battery pack. What implication will it have on the motor controller ... I am not sure ...

[AN]

Originally Posted by neutron256

It's possible. The only reason I haven't gone the direction of putting the power system in the trunk is the complexity. Same issue if you were to tuck it into the fender. Fabricating mounts, and the work to actually install it is very time consuming.

I really want to design a system that someone could build with minimal custom fabrication. But for others interested in a more complex setup I encourage them.

I agree ... I think Rob had a great reply on the battery pack being too far away from the motor ... its all big gauge high current wiring ... needs a lot of heavy duty connectors/ fuses ... cost goes up fast.

An easy way is to move the starter battery to the trunk and keep the ESC batteries in the engine bay. Also , using 6x or 8x 10Ah batteries will give more flexibility. I think 6x batteries will fit in the existing bay ... An appropriate sized/shaped dual cap combo can find some reasonable home int he engine bay too.

Also, neutron256 I think the MinnKota charger is a great find but kinda bulky. It would make aesthetic sense to have all the electronics as compact as possible .. ideally in a single enclosure.

[neutron256]

I currently have 12 1500f 2.7 volt ultra caps. I did the calculations once, I don't remember what it worked out to but it would be a good setup run in parallel with a 24V battery setup.

[Luckrider]

That would be ~32V in series.

[neutron256]

Originally Posted by AN

Also, neutron256 I think the MinnKota charger is a great find but kinda bulky. It would make aesthetic sense to have all the electronics as compact as possible .. ideally in a single enclosure.

I agree about it being bulky. It is just so perfect for this application otherwise though. I have considered cracking it open and seeing if it could be cut down in size at all.

[AN]

Originally Posted by neutron256

I currently have 12 1500f 2.7 volt ultra caps. I did the calculations once, I don't remember what it worked out to but it would be a good setup run in parallel with a 24V battery setup.

Nice .. how big are they ? any pics / links.

[neutron256]

Originally Posted by Luckrider

That would be ~32V in series.

Correct in theory, but without a charge balancing setup you don't really want to push them beyond 70-80% of their total charge.

[neutron256]

Originally Posted by AN

Nice .. how big are they ? any pics / links.

http://www.ebay.com/itm/Maxwell-1500...item461a649e50