Are these #s about right for a 48volt PDS cart ?

Great white north

Hello , guys & gals , thought I would pick some brains from the experts on
The best cart site on the web

Here we go , some background info. first : have 08 TXT PDS EZgo with 22 inch tires , stock motor , upgraded with Scotty s pkg to 48 volt with Alltrax controller , solenoid etc. Cart is lifted with 6 inch jakes long travel lift , have new Crown
CR260 amp/hr batteries approx 3- 4 month old 8- 6 volt system with extra 12 volt accessory battery to run lights and radio and winch in bag -well ( the 8- 6 volts are shoe -horned under seat ) also replaced driver side axil with bearings
With new oil in rear end

First Question - Is my range for my cart about right ? (1-person in cart 270ibs)

- charged battery pack until charger shutoff ( just prior to charger
Shutting off measured pack voltage 61.02 volts Equalization )
- waited 12 hours measured pack voltage again 52.29 volts
- individual batt . #s - batt.1 = 6.541, Batt.2=6.543,
- batt. 3=6.536, batt. 4=6.511,batt. 5=6.549,batt.6=6.538
- batt.7=6.510 , batt.8= 6.555
- Ran cart 13 miles on mild to medium terrain (hills)80% of
Which were gravel roads , 20% paved
- when I returned from trip let cart sit for approx. 30 to 40 min.
Measured pack voltage = 49.76volts with DVM , on SOC
( Scotty's ) =49.1 , individual batts: b1=6.227,b2=6.234,
b3=6.224,b4=6.180,b5=6.236,b6=6.226,b7=6.181,b8=6. 23

2nd question :, if the range is off how could I improve ?
using DPI charger set to mode 2
3rd question -my speed I top out at is 24-25 mph is that low ?
( measured with GPS on phone )

Sorry for the long drawn out info.
Cheers !

BGW

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beach cart

I am running same set up as yours. Cart has deka gc-45 batts. Your numbers seem right on, I run in the 6.5 range, batts 1.5 years old, my controller is 650 alltrax 2 ga cables. if its 95 degrees and I stay around 22 my range is around 30, with 60% pack left. There are so many variables, weight onboard ,tires inflated right. I baby my cart though, no sudden jumps, motor gets hot , like 190 I stop let it cool. My runs usually 10-15 miles, flat ground and all road. Be nice to those batts and check connections often, charge each day to shut off, they should serve you well.

crash test dummy

well with Canadian electric i would say it looks like it runs good ..
if you can get a hold of some US electric it will run better ...

JohnnieB

Q-1: Your "before" At-Rest voltages are so far off the top of the charts, I don't feel very confident estimating your range.

Try driving around two or three miles, let batteries rest for a half an hour and use that as the before At-Rest voltage.
Then drive 10-15 miles and get the "After" At-Rest voltage.

That should give us a couple data points that are on the charts, so a ballpark max range can be calculated.

If I assign 100% SoC to your before voltage, your 48V 260AH battery pack dropped to 75% SoC (49.76V) in 13 miles. If you limited yourself to no more than a 50% discharge, your projected max range is 26 miles, which is nearly 10 miles less than what I was getting from a 42V 245AH battery pack with a DCX400 and stock PDS motor.

It is also about 8.5 miles less the what my projected max range is with the DCX500 and D&D motor I now run.

What was the air temperature when you made the run?
You loose about 10% of your battery capacity/performance for every 20°F under 80°F.

Q-2: Call Crown and/or DPI and ask which mode setting to use. Trojan (Mode 2) is the lowest voltage and US Battery (Mode 1) is the highest.

Q-3: Yes, it is low.
With a stock PDS motor, a DCX400 and 18.3" tall tires, I got a solid 24MPH on level pavement @ 36V and 28MPH when I upped the pack to 42V.
Theoretically, with 22" tires and 48V, you should be getting at least 34MPH, but in reality, it will most likely be less.

--------
If you have wide, low pressure tires, they may be eating up some speed and range.

Great white north

Thanks guys, Crash , ill probably paying cheaper on us electricity

Johnny b - the at rest voltage is indeed after 12 hrs of rest , after charger shut off , Outside temp. was indeed cool (like fall ) -approx. 50 degrees F
Never checked inflation on tires , will get back with info.
I am going to call DPI today regarding correct mode , will keep you
Posted

JohnnieB

1. The newer 48V DPI chargers go into float charge after the regular charge cycle completes and 52.29V is roughly what the float charge voltage is for a 48V DPI charger. To get a true At-Rest voltage, you may have to have the batteries disconnected from the charger for 12 hours.

However, I have ran tests after the pack has been off float charge for over 12 hours, and after the cart has been drive a couple miles and rested, and starting immediately after being on float charge; And the results are pretty much the same. So I've reached the conclusion that there really isn't all that much energy stored in the "Surface charge" and start my test straight off float charge and call it 100% SoC, even though it is above the top of the charts.

The charts themselves, are based on Trojan battery data, but from what I have been able to determine, they are ballpark numbers for most batteries.


2. At 50°F, you were running a 48V 221AH battery pack. (260AH - 15%)

3. Some of the low pressure tires (<15PSI max inflation) take a lot of amps to turn and throw all my theoretical stuff out the window.

beach cart

Johnnie thanks for the info for both of us. I emailed DPI this morning to get right number to charge my Deka gc-45's. Or too just be sure.

JohnnieB

I'm not sure about Deka or Crown, but US Battery has some issues when their batteries are charged using the Trojan Battery charge curve designed into most golf cart battery chargers.

On the other hand, the DPI uses dV/dT (Change in On-Charge Voltage over Time) criteria to determine when battery is fully charged, rather than a preset voltage like most automatic chargers do, so a few hundredths of a volt per cell, or so, in the constant voltage absorption and constant voltage float charge phases may not matter all that much.

FWIW:
Mode 1 (US Battery) = 2.50VPC Absorption & 2.21VPC Float
Mode 2 (Trojan) = 2.35VPC Absorption & 2.19VPC Float
Mode 3 (Exide) = 2.40VPC Absorption & 2.20VPC Float
Mode 4 (Full River) = 2.45VPC Absorption. I think this mode is for AGM batteries and I'm not sure what the float level is.

Multiply VPC (Volts per Cell) by the number of 2V cells in you battery pack to get pack absorption and float voltages.

Great white north

Sorry Johnny , had emergency call to -day will call DPI tomorrow regarding correct charging algorithm
I do agree , I feel my top speed is a little low would like to get to bottom of problem i
Cheers !

Great white north

FYI Johnny : phoned DPI and you are correct the mode I was using was incorrect I need to use - full river -mode 4 , he said I was under charging batts . This will make big difference in run time he said ,
I would bet this is a common problem with lots of folks :- under charging
There batts . With wrong algorithm
Thanks Everybody for the info.
Now the only problem is increasing my speed fr: 24 -25 mph to 28-30
Any thoughts on that ? , without adding any money
Cheers !