Quote Originally Posted by MLA View Post
it requires 2 relays per pump to revers its polarity. This is too complicated
Yes, 2 per pump but I disagree about it being too complicated, just a little more complicated. You trade off some cheap relays for the heavy/expensive wire. Overall, it's a less expensive solution. The relays are another failure point but they are pretty reliable - In 20 years, I've had one failure in my '84 Jeep and no failures in any other vehicles. I'm making the assumption that the engine will be running while filling so I'd rather take up to 80A right near the alternator instead of running that current on the battery cables.

But... I have an ulterior motive. I'm dreaming up a geek project and would definitely need the relays for a control system.