Paul & Sabrina's cheap DIY 144v motor controller

[MPaulHolmes]

Yes the freewheel diode will see the full current going through the motor when the mosfets are off, so I would make sure it can carry the same current that the mosfet can do. For the capacitor, it's a little hard to know. Make sure your capacitors are rated for 105degC. It has worked in the past with me using like 10% of the current rating of the controller for the ripple rating on the electrolytic caps. The worst case is 50% I guess, though. So, ideally with a 500amp controller you would have 250amp of ripple current rating of capacitors. But in practice that really seems unnecessary.

[MPaulHolmes]

I'm getting a new DC board made. Someone already built a controller using the new board. He graciously filmed himself driving away so I could show how it worked. He has the current set to 1000amp. He's also using a 200v battery pack, using Chevy volt batteries:
https://blackfamily-my.sharepoint.co...uFcEg?e=svNOsh

The new board should be here in about 4 days I think. I'm so excited!!

[Don Gannon]

Hi Paul,

I have been following this thread for several months now. Just registered to toss in a request for the new DC control board. Will the old one that is listed on your site work with the board? The 3 IGBT one? Will need a BOM for it. I have the schematic thingstodo provided, and can work with that.

Should be no problems with assembly, as I have been doing electronics for several years. Have most of the tools, or access to them. A good buddy manages a state of the art machine shop, and I spent a few years as a machinist in the Navy.

[Don Gannon]

I have a '98 Ford Ranger 5 speed that is paid for that is the conversion candidate. So far, we have acquired ten 12 volt 10 ah LiFEPO4 batteries and about 40 feet of #2 welding cable. Crimpers and cutters are at the shop, so no problems there. We are planning on getting another ten for two banks to double the range. Amazon should be able to provide the rest.

[Don Gannon]

As to charging, what a POA. We are looking at the 24 volt charger that runs off 120 volts. Six of those per bank should do the job. This should balance things out fairly well and allow for easy troubleshooting of dead batteries.

Any guidance on chargers will be welcome. Access to 220 volt source is rather limited. Can do it with a looooong extension cord from the stove or dryer, but don't really want to do that.

[Piotrsko]

Based on my calcs you are going to have enough battery to go about 3 miles.

My 88 ranger does average about 430 watt hrs a mile. I have a 16 kw 192 vdc VOLT pack, and it gets perhaps 40 miles to a charge.

[Don Gannon]

Thanks Piotrsko,

I need to go at least sixty (safe) miles on a charge. So I am now looking at ten 130 ah AGM 12 volt deep cycle batteries as the primary pack, and maybe six or eight more as a reserve "get home" pack.
I must have miscalculated the kw/mile formulas. Those darn decimal points.

I will look at that again...

[MPaulHolmes]

The old DC board on the website is for the 144v 500amp controller. The new one is here:
https://pandspowerelectronics.ecwid....egory=16287307

It plugs right into 3 IGBT half bridges. I don't have much useful stuff to say about chargers. When I did the charging, I just used several 12v chargers that had isolated outputs so that they could each charge their own 12v battery. You could do that with 24v chargers and it would work fine.

[Don Gannon]

Ah. Excellent. I will be ordering one of these within the next few weeks. Is there a power board that is different? Or will the one on the website work with this newer controller?

[MPaulHolmes]

There's no power board. It just plugs into big IGBT modules like this (this is a bunch of pictures showing one possible assembly process for both the AC and DC motor controllers):
https://www.dropbox.com/s/iwhkjmo75w...05241.zip?dl=0