500amp series controller+ programmer for under $200

[augiedoggy]

I have been working on a 48v + lithium conversion on an old g8 and after buying a used "untested" alltrax 72sr500 that ended up having an intermittent overvoltage issue I decided to try one of the many clones of the Curtis 1205m-5603 500amp controllers... When I say clone I mean clone because the originals were apparently made in china before curtis ceased the agreement with the manufacturer. That manufacturer and apparently others are still making them without permission from curtis so take it for what it is. anyway...

I bought one of these for $150 (was supposed to be an open box but mine was new and sealed and the programming tool shows it was never used.)
https://www.ebay.com/itm/16402680016...8AAOSwbAZeGUjU

Now my cart has the 0-1k throttle which isnt listed as one of the 10 throttle options but I read that when you buy them preprogrammed for the 0-1k yamaha throttles from the golf cart supply comapnies they just use the #9 0-5k throttle selection and then set the "max throttle to 20%" (This works perfectly for full throttle range)

After doing this and enabling some other features such as limited speed reverse and the safety feature so it doesnt move when the key is activated under throttle as well I enabled the "boost" feature with works just like the max output setting on the alltrax to allow peaks of higher amp outputs than the following specs.
CURTIS Model: 1205M-5603
Norminal Battery Voltage (Volts): 48V (default setting) or 36V
1 Minute Current Rating (amps): 500
5 Minute Current Rating (amps): 350
1 Hour Current Rating (amps): 200
Plug Braking (A2 Busbar): Yes
PWM operating frequency: 15.6 kHz
Electrical isolation to heatsink (min.): 500 VAC
KSI input current (no contactors engaged

I was surprised to see there is real time monitoring features with the curtis programming software as well as equivalents for almost all of the features that both my alltrax controllers have. (there is no personality switch though)

so after watching this video,
https://www.youtube.com/watch?v=2p7X_wNF0hQ

I used this serial to usb adapter,
https://www.ebay.com/itm/25599425969...RoCFZYQAvD_BwE
(apparently this $7 cable works too but mine hasnt arrived yet to test)
https://www.ebay.com/itm/263711394959

I used this serial breakout board here,
https://www.amazon.com/dp/B076WVFXN8...roduct_details
(in hindsight I could have just used something like this since the included rs422 cable wont work for this,
https://www.ebay.com/itm/14483617936...Bk9SR7iXhe7XYQ

I then used an old molex connector from an old pc power supply like this one,
https://www.ebay.com/itm/18227646397...Bk9SR87Qle7XYQ

I followed this wiring diagram her
http://www.evbitz.uk/Curtis_Cable.html
To wire the 3 pins/wires to the #2,3 and #5 pin of the serial connector then plugged it all in and launched this software found here

https://www.nocoev.com/curtis/Software%201314-4401/

Once I launched it I just followed the directions from the video and programmed everything to my liking. I then put it in the cart and reconnected the laptop. I then used the monitoring feature to make sure the throttle as well as other features were working as programmed.

This unit has ALL the functionality in the software. I've read there are some clones out there which are stripped out with limited hardware inside which only allow limited functionality in the programming software.

I have only had this installed for a day but so far im thrilled, Time will tell how it holds up but after doing multiple searches and reading through the web as well as here for feedback I found positive feedback from just about everyone thats actually used them.

here are some pics of the cable I made and how I powered it to program it at my desk (you need a 20v+ power supply if your doing this outside of a cart.)

All in all I think this is a great cost effective way to get a more powerful controller in an older cart on a budget. This is a pretty hefty unit which weighs more than my larger alltrax sr72500.

[augiedoggy]

Sorry for the poor quality pics but you get the jist.

[augiedoggy]

Just an update on this.. Got it in the cart last week and got to do some test runs and tweak my reverse speed as well as throttle response curve. The cart is working fantastically.. I have a solar panel roof and mppt boost charger. as well as a diy 48v lithium pack installed.

[scottyb]

This is impressive, very resourceful of you. And solar too!
Is this something the average user can do or do we need an engineering degree to make this happen?

[augiedoggy]

Originally Posted by scottyb

This is impressive, very resourceful of you. And solar too!
Is this something the average user can do or do we need an engineering degree to make this happen?

Its actually pretty easy. No degree required.. Just the ability and will to follow directions.
I picked all this up from you tube videos and others on forums including this one. The solar panel setup literally only have positive and negative from the panel to the mppt charge controller and positive and negative from the controller to the battery. solar panel was $90 locally and the controller was $40 from ebay. I havent tested in full sun with my 50v pack yet but it charged with over 8 amps with my old 36v fla batteries.


Its true it might be more involved than some here want to mess with. I mention it for those who would be interested though. and those that might want to make improvements with a smaller budget commitment.

As far as connecting to the curtis clone and changing parameters thats also covered in a few different you tube videos. the biggest issue I had was the first usb to serial cable I tried was not rs232 compatible.

I did spend more time than I wanted trying to figure out a good radio memory solution. The relay approach Sergio mentioned in this forum wouldnt work for me since the presets would be lost in the short time it took for the relay to click over from the converter power to a battery.. the clock would keep its time ironically.
It wasnt until I found someone on another forum using a simple blocking diode in his rv with a small battery (I used a $15 4ah sla battery which charges off the reducer while powered up) that I found the perfect working solution that would still allow me to remotely deactivate the discharge on my lithium battery with the app and prevent some sort of incidental drainage or kids taking it for a joyride at the campground.

[kgsc]

Impressive. Never seen this cable setup. Do see it is set to OEM. Wonder if it can be set to developer..

Ad, could you post a better picture of the wiring connections on the serial adapter and molex?

[augiedoggy]

Originally Posted by kgsc

Impressive. Never seen this cable setup. Do see it is set to OEM. Wonder if it can be set to developer..

Ad, could you post a better picture of the wiring connections on the serial adapter and molex?

the wiring diagram is actually in a link in my first post... only 3 wires. ground to pin 5 transmit pin 2 and receive is pin #3.

I used what I used as far as an old pc power supply molex plug because im lazy and had a bunch in a box of old pc parts and didnt want to solder.

the $7 ebay usb to serial rs232 cable should be arriving today and I will test with that since it will make the adapter much cheaper to assemble.

[kgsc]

An option to the breakout board would be just to buy a cable and cut it in half..

https://www.officedepot.com/a/produc...F-Cable-Beige/

[augiedoggy]

Originally Posted by kgsc

An option to the breakout board would be just to buy a cable and cut it in half..

https://www.officedepot.com/a/produc...F-Cable-Beige/

yeah I thought of that too but figured Id keep my options open with the breakout board plus It could be useful on another project in the future. (they are also only $5-7 shipped by themselves on ebay so cost is kind of a moot point)

I dont recall seeing the developer option in the 3.12v version of curtis software I used. ther were a bunch of options listed though.. Ill have to take another look when I test the new cable.

[kgsc]

That cable was like $5 so just thought it could be an option.

Not sure if v3.12 can get to development mode but it wouldn’t really show up in the pull down. I’m using v4.6 with an FDTI cable so different animal.