Amp draw???

[interstate]

Controller ready for a test drive when the weather breaks later this week. Real time data is pretty neat. It shows the current draw on the battery side of the controller feeding in and the current going out to the motor from the controller.

For example, while on jack stands at at low speed, the batteries saw a 6 amp draw while the esc was putting out 25 amps to the motor. I don't fully understand these figures and may edit this post after running some real tests under load.

[interstate]

I have some spotty numbers due to the all trax software and esc oddities.


I pull a trailer with my golf cart, so I tested with the trailer unloaded and one adult driver and two little kids aboard.

1987 club car DS
23" radial street tires
Long travel lift kit
Heavy duty rear springs
4 gauge wires, connectors not cleaned for this season yet, so some corrosion
Stock F R switch
3 year old US batteries 2200's 8 x 6v configuration. Two batteries in bag well.
All Trax 4844 controller
Street legal kit
Dash kit with full blown stereo
12 battery for lights on board
No top on golf cart
Rear steel seat and trailer hitch

Trailer weighs about 700 pounds
Golf cart about 1,100 pounds

From dead stop, hitting full throttle we saw a spike of about 385 amps.

Within within 10 seconds the amps leveled out to about 150a continuous while still accelerating.

After reaching full throttle we saw between 65a-95a continuous

Partial throttle at slow cruise speed showed 25-40 amps.

All test runs we're done on blacktop and length was one city block.


I pull this trailer for one week while on vacation each year for a distance of one mile each way at 900 pounds fully loaded. Throughout the summer I pull it about three blocks each way a few times per week. The rest of the time this is a family cruiser city transport vehicle with typical parents up front and young kids strapped into the rear seat.

Will test again this weekend without trailer.

[sunoco]

What throttle are you using? When you say stock F/R you mean the one that came in the cart? Are you using the original 36v motor?

[jjance]

Just as in the theoretical values I posted a while back. Max is close to the output of the controller. The cruising value is 100 amps for a 5 HP motor. My 50 amp example was for a 3.3hp motor. I don't know why the manufacturer don't give the KwH rating of their batterys. Instead of the other mumbo-jumbo. So all you need to know about those lithium batteries is the KwH rating of them. Amp hours times pack voltage = KwH What you have now is 11.5 KwH.

[interstate]

Plum Quick turned my stock 36v motor into a purple Bandit capable of handling the 48v upgrade.

The F/R switch is the stock one that came with the cart. I don't know if the heavy duty units are worth the cost and effort. Maybe they are? I'm open to input.

I use the pot box for throttle. Can't recall exactly what is is.

[sportcoupe]

Originally Posted by jjance

So all you need to know about those lithium batteries is the KwH rating of them. Amp hours times pack voltage = KwH What you have now is 11.5 KwH.

That's where it becomes tricky. Golf cart batteries have their Ah rating specified at the 20 hour rate. Lithium batteries often use the 1 hour rate for Ah. Golf cart battery manufacturers doesn't advertise their 1 hour Ah rating.

[eric1565]

If you go to good web sites on batteries, they will give you the 5, 10, 20, 100 hr rating on your battery. They MAY also tell you the ah if you draw 75 amps cont. For example, a 225 ah battery (20h discharge) will have and ACTUAL 143 ah if you drw 75 amps continous. Also like we all know only draw your battery down to 50% charge, so your ACTUAL capacity of your lead pack for a "225 ah" battery is 71ah.

Lead sucks... but cheap and everybody has the chargers for it, so it continues to get used :(

[PingEye3]

Whatever current draw you have now with all that weight at full throttle you will probably never reach with lithium at least not for long, lighter weight and higher voltage. The length of time you are staying with high current draw now will be much less with lithium. With my Executioner and 400A controller on lithiium, I can hit 325A for about a second, then it drops rapidly.