36 Volt to 48 Volt conversion- battery cable lengths?

[flharleycop]

Originally Posted by JohnnieB

Seven 6V-245AH batteries fit nicely.

I believe you have to relocated the controller/solenoid to fit the eighth battery in front of the passenger side wheel-well, but that is relatively easy to do with a PDS or DCS.

What is your goal for the cart speed wise?
What controller and solenoid do you have?
What is your tire height?

You can get 28MPH on stock height tires and a stock PDS motor with a DCX400 controller and a 42V battery pack.

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My goal was range rather than speed or torque, but I ended up with all three.



If the seven 245AH batteries hadn't given me the range I wanted, I was going to add an eighth battery and relocate the controller, solenoid and 12V DC-DC converter (and some other stuff) on a heatsink made out of 3/16 aluminum, mounted on the frame above the motor.

I would be real happy if I could get 23-25 really like 25mph. I didn't know I could just add another 6v for 42v. I have 22 inch tires and a lift now. Mine stock gives me a solid 18 sometimes with wind 19. Currently I think my ranges is around 20-25 miles. I have never ran it straight on the same day, I got that figure over three days to see just how far I could go without being too hard on the batteries. To used it on the beach I have to travel 4 miles there, plus a bit of driving on the sand to check out the beautiful women figure 5/10 miles then 4 miles back home to charge for the next trip. The beach speed limit is 10mph so I only need the speed to get there and back quicker.

[JohnnieB]

Originally Posted by sportcoupe

There is more then one way to arrange six 8v batteries in a txt tray. Depending on your existing cables you may have to change a few, most likely you will.

I believe this is the cleanest way to arrange 8v batts.

It is an orderly arrangement and appears to be well maintained.
The DCX to PDS adapter cable is a plumber's nightmare and vulnerable to mechanical stresses, so I Ty-wrapped the control wires to a high current cable to reduce the amount of flexing they are exposed to.

It also shows how much room is available in front of the DCX controller and Super-Duty solenoid.
A 6V cart battery is very close to an 8V cart battery in length and width, and it doesn't look like a battery that size could be shoehorned in where the orange 12V accessory battery is located.

[JohnnieB]

Originally Posted by flharleycop

I would be real happy if I could get 23-25 really like 25mph. I didn't know I could just add another 6v for 42v. I have 22 inch tires and a lift now. Mine stock gives me a solid 18 sometimes with wind 19. Currently I think my ranges is around 20-25 miles. I have never ran it straight on the same day, I got that figure over three days to see just how far I could go without being too hard on the batteries. To used it on the beach I have to travel 4 miles there, plus a bit of driving on the sand to check out the beautiful women figure 5/10 miles then 4 miles back home to charge for the next trip. The beach speed limit is 10mph so I only need the speed to get there and back quicker.

Are you running in the Mild Hill PDS mode? Or are you running in the Freedom mode and have low pressure tires?

A stock PDS controller limits the motor to about 4400 RPM in Freedom mode, which is mathematically about 18 MPH on stock height tires and about 23 MPH on 22" tires, but the 4" taller tire costs you about 20% of the available torque, so the cart runs out of high end torque before it reaches that speed. And low pressure (<10 PSI) tires take more torque to turn than standard pressure (>20 PSI) tires.

However, in Mild Hill mode, a standard pressure 22" tire would give you about 18-19 MPH.

As for speed: It depends on the type tires you have.
On 18.3" tires inflated to 22 PSI, I got 24 MPH with a DCX400 feeding a stock PDS motor from a 36V-225AH battery pack. (Range about 30 Mi.)
When I went to a 42V-245AH battery pack the speed went up to 28 MPH and the range went to 36 Mi.

Mathematically, that translates to 29 MPH @ 36V on 22" tires and 34 MPH at 42V, but you probably won't see those speeds in the real world due to the rolling resistance of the tires and other factors.

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For maximum lifespan, the batteries ought to be charged after each use, but you can estimate your cart's range by using the At-Rest voltage of the battery pack before and after a drive to the beach to ogle the bikinis.

Basically calculate how many AH your cart uses per mile and divide that number into 50% of your battery pack's AH capacity.
Rough the same way you estimate how far you car will go on a half tank of gas.

[flharleycop]

Originally Posted by JohnnieB

Are you running in the Mild Hill PDS mode? Or are you running in the Freedom mode and have low pressure tires?

A stock PDS controller limits the motor to about 4400 RPM in Freedom mode, which is mathematically about 18 MPH on stock height tires and about 23 MPH on 22" tires, but the 4" taller tire costs you about 20% of the available torque, so the cart runs out of high end torque before it reaches that speed. And low pressure (<10 PSI) tires take more torque to turn than standard pressure (>20 PSI) tires.

However, in Mild Hill mode, a standard pressure 22" tire would give you about 18-19 MPH.

As for speed: It depends on the type tires you have.
On 18.3" tires inflated to 22 PSI, I got 24 MPH with a DCX400 feeding a stock PDS motor from a 36V-225AH battery pack. (Range about 30 Mi.)
When I went to a 42V-245AH battery pack the speed went up to 28 MPH and the range went to 36 Mi.

Mathematically, that translates to 29 MPH @ 36V on 22" tires and 34 MPH at 42V, but you probably won't see those speeds in the real world due to the rolling resistance of the tires and other factors.

----------
For maximum lifespan, the batteries ought to be charged after each use, but you can estimate your cart's range by using the At-Rest voltage of the battery pack before and after a drive to the beach to ogle the bikinis.

Basically calculate how many AH your cart uses per mile and divide that number into 50% of your battery pack's AH capacity.
Rough the same way you estimate how far you car will go on a half tank of gas.

Thanks for the info, the tech stuff I don’t understand but I got the big chunks. My tires are 22 inch and street tread but the max tire pressure is 10 psi, I do inflate them to 11.5. As far as the freedom mode or hill mode I think I am in freedom. I forgot how to get into the diagnostic mode to hear the beeps and don’t remember if freedom is 4 beeps or what. If you tell me that I can check on which I am in.
again thank you for your time.

[JohnnieB]

Originally Posted by flharleycop

Thanks for the info, the tech stuff I don’t understand but I got the big chunks. My tires are 22 inch and street tread but the max tire pressure is 10 psi, I do inflate them to 11.5. As far as the freedom mode or hill mode I think I am in freedom. I forgot how to get into the diagnostic mode to hear the beeps and don’t remember if freedom is 4 beeps or what. If you tell me that I can check on which I am in.
again thank you for your time.

The text at the bottom of the label tells you how to get into Diagnostic mode.

Freedom mode is 4 beeps.

Sounds like the tires are holding your top speed down some, but not quite as much as some of them do.

A DCX controller and 42V still ought to get you into the mid to upper 20's, maybe even the low 30's.

[flharleycop]

Originally Posted by JohnnieB

The text at the bottom of the label tells you how to get into Diagnostic mode.

Freedom mode is 4 beeps.

Sounds like the tires are holding your top speed down some, but not quite as much as some of them do.

A DCX controller and 42V still ought to get you into the mid to upper 20's, maybe even the low 30's.

Do I have a DCX controller or do I need to buy one? If I just add another 6v battery for 42v to I have to get another charger or anything else? Sorry for the questions but I am still trying to understand battery carts, if it had a carburetor I could figure it out.

[JohnnieB]

Originally Posted by flharleycop

Do I have a DCX controller or do I need to buy one? If I just add another 6v battery for 42v to I have to get another charger or anything else? Sorry for the questions but I am still trying to understand battery carts, if it had a carburetor I could figure it out.

You have a stock PDS 36V controller (Curtis 1206MX), so you will need to buy a controller and a solenoid and a charger if you increase the battery pack voltage.

Alltrax is a company that builds aftermarket controllers and DCX is a family of controllers they make for Sepex (Separately Excited) motors, the type motor that is in your cart. The family members are DCX300, DCX400, DCX500 and DCX600, the numbers indicating the Amp rating.

Unlike the Curtis 1206MX, the DCX family of controllers are designed to operate with pack voltages anywhere from 24V to 48V.

Also unlike the Curtis 1206MX, the DCX family of controllers do not limit the max RPM of the motor, This feature alone will up the top speed of an otherwise stock PDS cart into the low to mid 20's.

In addition, the DCX controllers are user programmable, so they can be tailored to better suit your needs.

You have 22" tires, so you are loosing about 20% of the available torque. To regain that loss, you have to increase the Amps the motor can draw.
The Curtis 1206MX is a 300A controller, so you need a controller with at least a 360A rating to offset the torque loss caused by the taller tires.

A DCX400 is a 400A controller, so it would have a torque gain of 33% and when combined with the 20% torque loss from the tires, you would have a net torque gain of a bit over 10%.

A DCX500 or DCX600 would up the torque even more, but they can deliver more amps than a stock PDS motor can handle on an ongoing basis, so a more robust motor would have to installed. (It will work, just not for long. Sorta like installing a Jimmy 471 under the carburetor of an otherwise stock engine.)

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The stock solenoid is rated at 85A continuous. At best, it is marginal for a 300A controller. In addition to the amp rating of the contacts, the coil will only operate over a narrow voltage range centered on 36V. If the voltage is too low, the contacts don't close properly. If the voltage is too high, the coil burns out.

Some solenoids have coils that will operate over a wider voltage range. I'm not sure about other solenoids from other sources, but I know from personal experience that the Super-Duty 48V solenoid (400A continuous/1000A peak) that Carts Unlimited sells (scottyb), will operate at 36V and 42V, and other forum members are running it at 48V.
So it is a good choice if you want run at 36V now and plan to upgrade the pack to a higher voltage later. Also, at 1000A peak, it will handle the amps passed by any controller that most people are likely to installed.

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Battery chargers have to match the pack voltage and have a charge profile compatible with the brand battery being charged.
The DPI Accusense chargers have two main components, a step-down transformer and a PCB (Printed Circuit Board). The transformer used in the 36V version is too small to power a 42V PCB, but the same transformer is used in both the 42V and 48V versions.

I had a 36V DPI and had to buy a 42V one when I went to 42V, but if I ever go to 48V, all I have to buy is the 48V PCB to convert my 42V charger to a 48V charger.

Also, the DPI has user selectable charge profiles for different brands of batteries.

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Hope this helps.

Like working on engines with carburetors, asking questions before jumping in is a good thing.

[flharleycop]

Originally Posted by JohnnieB

You have a stock PDS 36V controller (Curtis 1206MX), so you will need to buy a controller and a solenoid and a charger if you increase the battery pack voltage.

Alltrax is a company that builds aftermarket controllers and DCX is a family of controllers they make for Sepex (Separately Excited) motors, the type motor that is in your cart. The family members are DCX300, DCX400, DCX500 and DCX600, the numbers indicating the Amp rating.

Unlike the Curtis 1206MX, the DCX family of controllers are designed to operate with pack voltages anywhere from 24V to 48V.

Also unlike the Curtis 1206MX, the DCX family of controllers do not limit the max RPM of the motor, This feature alone will up the top speed of an otherwise stock PDS cart into the low to mid 20's.

In addition, the DCX controllers are user programmable, so they can be tailored to better suit your needs.

You have 22" tires, so you are loosing about 20% of the available torque. To regain that loss, you have to increase the Amps the motor can draw.
The Curtis 1206MX is a 300A controller, so you need a controller with at least a 360A rating to offset the torque loss caused by the taller tires.

A DCX400 is a 400A controller, so it would have a torque gain of 33% and when combined with the 20% torque loss from the tires, you would have a net torque gain of a bit over 10%.

A DCX500 or DCX600 would up the torque even more, but they can deliver more amps than a stock PDS motor can handle on an ongoing basis, so a more robust motor would have to installed. (It will work, just not for long. Sorta like installing a Jimmy 471 under the carburetor of an otherwise stock engine.)

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The stock solenoid is rated at 85A continuous. At best, it is marginal for a 300A controller. In addition to the amp rating of the contacts, the coil will only operate over a narrow voltage range centered on 36V. If the voltage is too low, the contacts don't close properly. If the voltage is too high, the coil burns out.

Some solenoids have coils that will operate over a wider voltage range. I'm not sure about other solenoids from other sources, but I know from personal experience that the Super-Duty 48V solenoid (400A continuous/1000A peak) that Carts Unlimited sells (scottyb), will operate at 36V and 42V, and other forum members are running it at 48V.
So it is a good choice if you want run at 36V now and plan to upgrade the pack to a higher voltage later. Also, at 1000A peak, it will handle the amps passed by any controller that most people are likely to installed.

----------
Battery chargers have to match the pack voltage and have a charge profile compatible with the brand battery being charged.
The DPI Accusense chargers have two main components, a step-down transformer and a PCB (Printed Circuit Board). The transformer used in the 36V version is too small to power a 42V PCB, but the same transformer is used in both the 42V and 48V versions.

I had a 36V DPI and had to buy a 42V one when I went to 42V, but if I ever go to 48V, all I have to buy is the 48V PCB to convert my 42V charger to a 48V charger.

Also, the DPI has user selectable charge profiles for different brands of batteries.

-----------
Hope this helps.

Like working on engines with carburetors, asking questions before jumping in is a good thing.

Thank you for the detailed explanation, It cleared up a lot of questions I have had. Once I get my Florida Insurance for the cart my next project is to speed it up. I think I am going to try the new controller, solenoid, as you suggested at 36v and see what I get there. If I am good with that, then I will stop and not get the extra battery and charger.

again thank you!

[JohnnieB]

One thing I failed to mention, replace your high current cables. (All 10 of them)

Back in Jun-2011 when I got my 2008 PDS, the cables looked pretty good, but I found out they were pretty sick when I compared them to new set of 2Ga cables with silver soldered lugs.

My cart was fresh off a 3yr lease at a golf course in Arizona where the air is dry, while your 2008 PDS is going on 6 years old and has been expose to the salty humid air of Florida. My guess is your cables are sicker now than mine were two years ago.

New 4Ga cables ought to suffice, but I went with 2Ga because I'm an efficiency nut.

[flharleycop]

Originally Posted by JohnnieB

One thing I failed to mention, replace your high current cables. (All 10 of them)

Back in Jun-2011 when I got my 2008 PDS, the cables looked pretty good, but I found out they were pretty sick when I compared them to new set of 2Ga cables with silver soldered lugs.

My cart was fresh off a 3yr lease at a golf course in Arizona where the air is dry, while your 2008 PDS is going on 5 years old and has been expose to the salty humid air of Florida. My guess is your cables are sicker now than mine were two years ago.

New 4Ga cables ought to suffice, but I went with 2Ga because I'm an efficiency nut.

Thanks!