36v resistor cart lithium upgrade

[Jgoff72]

I’m looking into building a 36v lithium pack for my resistor cart. I’m trying to figure out how to wire up the reverse wire so the cart only gets half voltage in reverse. If I build a standard lithium pack it will only have two connections (+) and (-) at 36v. Any suggestions? Is there a reducer I can run off the pack to lower the voltage for reverse?

[Pat911]

Just wire it off the full pack voltage but go easy with the pedal.

[augiedoggy]

Originally Posted by Jgoff72

I’m looking into building a 36v lithium pack for my resistor cart. I’m trying to figure out how to wire up the reverse wire so the cart only gets half voltage in reverse. If I build a standard lithium pack it will only have two connections (+) and (-) at 36v. Any suggestions? Is there a reducer I can run off the pack to lower the voltage for reverse?

I know this isnt what your asking but bare with me for a minute.



I just upgraded my old yamaha from 36v to 48v diy lithium and it was a pretty significant jump in power and speed.
Since you have an old resister series cart you have a lot of inexpensive ways to swap in either a 36v or 48v controller with solenoid and drastically increase your range. The resisters carts always draw full power from your battery regardless of how much throttle your applying which is very inefficient.

You could use one of these inexpensive controllers which have an option to set the max reverse speed to whatever you want.. I installed one of these open box controllers in my cart last week. I have a thread on how to program them yourself if you like and change whatever setting you want. I realize this might be more involved than you feel comfortable with but its an option. I could even program it for you if you like if you were up to pay the shipping cost. this same controller can be programmed for either 36 or 48v.
https://www.ebay.com/itm/17559501343...Bk9SR6T1l9HbYQ

btw it says open box but mine was new and sealed..

[CP241]

Agree 100% with augie. The problem with running lithium on a resistor cart is you can’t control the current draw, it’s basically going to draw full capable amperage regardless if you’re doing 2mph or 20. All the excess is just being turned into heat in the resistor coils. And depending on the pack you go with, you may run into issues tripping the BMS because of this.

That said, and my .02… if you’re going to drop the $ on lithium I would go with 48v. 36v wouldn’t even be a consideration. You’ll get a lot more power and speed than 36v and the motor will handle it just fine. Get a PB6 and a controller of some sort to control the current draw and you’ll be fine.

[augiedoggy]

^ I agree on going 48v.. My cart went from a top speed of 14mph to 20 from the swap.

[Jgoff72]

So I’m definitely not opposed to a controller setup. The cart is currently bare. Previous owner removed all the resistor coils and wiring. I had planned on going Navitas ac with it but was just going to get batteries in it and get it going first. I also contemplated building a 48v pack based off auggiedoggy’s most recent budget build and just put a 48v solenoid in it until I found a suitable controller. I ran my previous cart WOT pretty much every where as I live on 10 acres of flat ground.

[scottyb]

The Curtis knock-off shown does not have a reduced reverse speed option. That would have to be done with a reduced throttle signal.
I've been looking at these fake Curtis controls for years - I wasn't sure the public was ready but the cost of a good controller keeps going up and up and up... making these look more appealing. Is there a warranty offered in the link you posted?

[augiedoggy]

Originally Posted by scottyb

The Curtis knock-off shown does not have a reduced reverse speed option. That would have to be done with a reduced throttle signal.
I've been looking at these fake Curtis controls for years - I wasn't sure the public was ready but the cost of a good controller keeps going up and up and up... making these look more appealing. Is there a warranty offered in the link you posted?

Mine does... I have the reverse set to a max of 40% currently after first trying 60% they addedit with the new design so the ones you looked at might not have the j5 pin input for it.
Honestly Ive been comparing the options in the software to my alltrax sr controller and besides the personality switch there seems to be equivalent setting for everything. theres even a "boost feature" that increases the amp output above the rated max for short periods of time like the altrax has.

the seller I bought from claims a 2 year warranty but I always take these things with a grain of salt.. as far as being "fakes"
Are they all? I mean some of these are from the manufacturer that made the genuine curtis controllers before the plans were leaked as is common with pretty much anything made in china and Curtis severed the manufacturing relationship.

im quite sure these clones are not all created equal and some are missing hardware and related features in the software. mine does not have the curtis logo anywhere on it like the one I linked above. however I bought mine from this seller and it appears he does carry the ones with the fake logo so maybe both are from the same manufacturer? its possible they had a grey market contract to sell with or without the curtis logo to some countries.
https://www.ebay.com/itm/16402680016...8AAOSwbAZeGUjU
I bet the manufacturer recently changed the sticker and all these open box units like the new one I bought are just old stock with the old sticker..

it was also marketed as the 1205-5603 and the P125m-5306 controller. there was nothing greyed out in the software on mine and it appears to work very well but I havent put it through any extreme testing yet.

Scotty if you were looking to supply these I would look at alibaba and deal directly with a manufacturer if it were me. better support and accountability.

Sorry OP dont mean to hijack your thread.

[jalexand]

Originally Posted by augiedoggy

You could use one of these inexpensive controllers which have an option to set the max reverse speed to whatever you want.. I installed one of these open box controllers in my cart last week. I have a thread on how to program them yourself if you like and change whatever setting you want. I realize this might be more involved than you feel comfortable with but its an option. I could even program it for you if you like if you were up to pay the shipping cost. this same controller can be programmed for either 36 or 48v.
https://www.ebay.com/itm/17559501343...Bk9SR6T1l9HbYQ

btw it says open box but mine was new and sealed..

That ebay link is broken. I also have a 36V cart that I would like to do a drop in lithium replacement. Can you give me something to search for on Ebay.