E825 losing power

Hey all- I have a 2002 e825 with lead acid batteries that are one month old and stock motor (modified speed control because it used to have a dd motor and it will go over 25 without a governor kicking in ) It has great power and will do about 28mph but after about 4 miles, the battery says 90 percent and I notice a huge loss in power. Will still go but goes very slow on hills and will go about 22 on flats. After charging it has full power. Is this weird to loose so much power and still show 90 percent? Figured it’s the batteries or maybe motor getting hot?

On this motor is there a temp sensor? (two black wires coming out of the end of the motor where the speed sensor is)
It connects to the car with a two pin delphi connector.

Chances are the poor little thing is loving the extra juice from it being turned up, but since it is not really designed for it’s current programming, and it is not vented/fanned at all, then it is actually overheating and telling the controller to cut back on the power.

Check your motor temp. It is probably pretty hot.

If you look on the display when it shows the 90, does it also light up the little wrench?

Welcome to code 90
It is an obscure code that did not make it into all of the docs. It might have been left over from another vehicle the controllers are used in.

If you want to test this overheat theory, run the car until it happens again, then find that connector down near the motor and pull it apart. Jump the two pin connector on the car side of the harness with the little bit of wire you thoughtfully packed in your pocket. Be glad that you even thought enough to pre-strip the ends to make this test easier. The car should be back up to normal speed again.

Warning: Your motor will not be very happy with you.
Do this as a short run test only.

Then go look look for some replacement brushes for your blue R4F motor again.

Thanks for the reply! Yes temp sensor on this motor. I think that’s exactly what is going on.

Actually, this motor has one black a red and a green. I actually happened upon a brand new R4Fun motor locally two days ago and put that in instead. Cart went 37mph! Anyways, attempted to drive it to work this morning ( 5 miles) and it had a dramatic reduction in power at about 2 miles and I turned back home and barely made it just creeping along at 5mph. Battery still says 85 percent. I haven’t got out my battery tester to test all six but still seems strange to show 85 percent with zero power. Seems that I still have the same problem, just happens faster now with the new motor. Bad batteries?

Maybe one bad battery, cable or connection…

This is one reason I don’t like shotgunning parts at the car until it works. If you never find a problem, then you don’t know if you fixed it.

Yes, the speed sensor has three wires. They are Black, Red, and Green. That is why I called out the TWO wire connection to look for. If you don’t have a temp sensor (blue motors do not), those two wires need to be connected.
Thinking out loud-
Chances are that if you came from a blue motor, and fell back to your spare GE motor, your temp sensor was probably bypassed already. I was just pointing it out. The display just happened to land on 90, which made me think the original bypass may be glitchy.

If your car is taking a nose dive while you are driving around, it is telling you something. You REALLY need to get an eye on your batteries. Give them a full workup. Pay special attention to all of the connections. They need to be tight and clean. Look for signs of heat.

We have a cushman with nine 8v batteries at work. It would work.some days others it would run out of juce real fast. One of the batteries was buried behind a plastic shield. Had no nut on on battery cable…

Thanks guys. I’ll take a look when I get home from work in a couple days.

That’s a good one.

I don’t make a habit of channeling George Takei very often but now seems like a good time for this:

George Takei gifs - Find & Share on GIPHY

Well, I’m still at a loss. All connections look tight, no corrosion, and all batteries tested good (5 at 100 percent one at 90) on the tester

Fasten your meter ont the POS, and NEG posts on top of your controller. If more convenient, make an extension to get it out to where you can see it while driving.

Let’s make sure this is not a voltage issue while driving.

Note what it is doing when it is driving nice, then when it bogs down.

Is this with a load tester or just a digital volt meter? If youre just using a volt meter, you should do a brake stand test on each battery. The stinker shouldl quivckly become apparent