TXT 48V Travel Range

[Glade Rider]

Originally Posted by ThreeCW

Battery "gassing" (bubbling) is normal during the final cycle (finish charge) of the charging process.

Find attached the some Trojan information which shows you the various charge cycles (bulk charge, absorption charge and finish charge). Finish charge at approx. 64.8 volts and 2 to 6 amps is where you will see the most prolific "gassing".

Also refer to Scotty's Battery Break In Recommendations here: http://www.cartsunlimited.net/battery-break-in-.html. He has some very good information here about breaking in and maintaining your batteries.

I have also attached a State of Charge chart for your reference. You can measure your "stabilized" voltage and determine the State of Charge using this chart.

Welcome to the forum

Thanks for the info and attachments. I have a Schauer charger that stopped sensing when the batteries were at full charge and would stay on. Batteries would bubble, overcharge and eventually ruined them. The yewy charger goes from red (charging) to flashing green (Batteries Bubbling Hard) and I was afraid to let it continue. Was waiting for solid green (Fully Charged). Anything in the charging system other than a bad battery that can cause the charger to not stop charging/Overcharging? Or is is not that complicated, just a bad charger.

Learning curve happening here.

[DaveTM]

BTW.....to prevent the green gack from occurring on your terminals, slather....yes, SLATHER your terminals and your cable ends with this product. You can buy this at Home Depot or Lowes. Proper application (full coverage) will stop terminal corrosion and make your maintenance much easier.

[JohnnieB]

Originally Posted by Glade Rider

Have a 48V TXT - New Trojan T125, 2 Gage cable, MZJ400 solenoid, Plum Quick -Bandit Motor, Altrax DCX 500 Amp Controller, 23" Tall tires, Stock Gears. 31.5 MPH/GPS. Range is approximately 13 miles when the battery pack hits 50%. Motor runs a little warm - 200-220 on a long haul. Batteries are new and on there 7th charge. Distance seem right? Thought I could travel farther.

Testing new Altrax XCT 500 Amp Controller and Plum Quick Barracuda Motor Next Week. Hoping for more torque/speed less heat.

Some things didn't add up in your first post in this thread and were never clarified in subsequent posts.
Do you have a TXT48 or a TXT-PDS that was upgraded to 48V?

The reason I ask is I'm pretty sure a TXT48 comes with a 6x8V battery pack and the earlier ones may have had a 4x12V pack, but you say your cart has new Trojan T-125 batteries, which are 6V 240AH batteries and you would have to have eight of them for a 48V pack (8x6V).

Also, with eight T-125 batteries you'd have a bit over 11.5kWh of stored energy and only getting a range of 13 miles, while my 42V pack has a bit under 10.3kWh and I have a range of over 30 miles. My cart has smaller tires and no rear seat, but they are both sepex drives and that is a huge difference in "gas" mileage.

[Glade Rider]

Originally Posted by JohnnieB

Some things didn't add up in your first post in this thread and were never clarified in subsequent posts.
Do you have a TXT48 or a TXT-PDS that was upgraded to 48V?

The reason I ask is I'm pretty sure a TXT48 comes with a 6x8V battery pack and the earlier ones may have had a 4x12V pack, but you say your cart has new Trojan T-125 batteries, which are 6V 240AH batteries and you would have to have eight of them for a 48V pack (8x6V).

Also, with eight T-125 batteries you'd have a bit over 11.5kWh of stored energy and only getting a range of 13 miles, while my 42V pack has a bit under 10.3kWh and I have a range of over 30 miles. My cart has smaller tires and no rear seat, but they are both sepex drives and that is a huge difference in "gas" mileage.

Sorry, I have a TXT-PDS that I upgraded to 48V which has 8 new 6V Trojan T-125 Batteries. The run time seems to be increasing as I discharge and re-charge the pack. I GPS it yesterday at 32.0 MPH. I'm going to GPS the distance again and see what mileage I'm getting. Data Plate Manuf. Code / Serial No. D501 1366149. Not sure if this helps identify the cart type?

I ordered the Yewy UY1200Z charger. When I charge the pack and the charger goes into the CV phase( green light blinking) the batteries are bubbling pretty hard like boiling water, is that normal? I understand that is referred to as gassing but is bubbling pretty hard. Just want to make sure I'm not damaging new batteries. Thanks!!

[Glade Rider]

Originally Posted by DaveTM

BTW.....to prevent the green gack from occurring on your terminals, slather....yes, SLATHER your terminals and your cable ends with this product. You can buy this at Home Depot or Lowes. Proper application (full coverage) will stop terminal corrosion and make your maintenance much easier.

Thanks for the info! Will check it out.

[JohnnieB]

Originally Posted by Glade Rider

Thanks for the info and attachments. I have a Schauer charger that stopped sensing when the batteries were at full charge and would stay on. Batteries would bubble, overcharge and eventually ruined them. The yewy charger goes from red (charging) to flashing green (Batteries Bubbling Hard) and I was afraid to let it continue. Was waiting for solid green (Fully Charged). Anything in the charging system other than a bad battery that can cause the charger to not stop charging/Overcharging? Or is is not that complicated, just a bad charger.

Learning curve happening here.

A lead-acid battery isn't fully charged until the specific gravity of the electrolyte ceases to increase while a charging current is passing through it. Since the on-charge voltage tracks the SG of the electrolyte, it can be inferred that a lead-acid battery isn't fully charged until its on-charge voltage ceases to increase while a charging current is passing through it.

That information has been known to battery manufacturers and battery charger designers for many decades, but the electronics needed to detect a cease in on-charge voltage rise was too bulky, too unreliable or too expensive to incorporate in consumer grade battery chargers until the last few decades of the 20th century, so the battery chargers were designed to terminate the charge cycle when a predetermined on-charge voltage was reached. The voltage picked was compromise that was high enough to almost fully charge newer batteries and low enough not to overcharge older batteries. For Trojan brand cart batteries 2.5VPC (Volts per Cell) was picked, which is 45V for a 36V pack and 60V for a 48V pack.

Now that the needed electronic are compact, reliable and inexpensive, chargers use dV/dT (change in voltage over change in time) to terminate the charge cycle and it is the batteries themselves that determine when they are fully charged.

If the Schauer charger isn't new, it is likely to be the predetermined voltage cutoff type and needs the control board repaired/replaced. Of course there are some other things that will keep it from sensing the pack's on-charge voltage correctly, so some troubleshooting is needed. Also, a bad battery can keep the pack voltage below the cutoff voltage.

---------
Gassing (bubbling) is a normal part of charging wet-cell lead-acid batteries.

The Yewy is going to charge the pack until the on-charge voltage stops rising and then switch over to a float charge mode. The max on-charge voltage reached will likely be less than 65V for a 48V pack of Trojan brand wet-cell lead-acid batteries.

Also, the on-charge voltage of each individual battery in the pack ought to be the same, or very near to the same while the same amps are flowing through them. in other words, measure the individual battery voltages when the charger amps isn't changing rapidly.

[JohnnieB]

Originally Posted by Glade Rider

Sorry, I have a TXT-PDS that I upgraded to 48V which has 8 new 6V Trojan T-125 Batteries. The run time seems to be increasing as I discharge and re-charge the pack. I GPS it yesterday at 32.0 MPH. I'm going to GPS the distance again and see what mileage I'm getting. Data Plate Manuf. Code / Serial No. D501 1366149. Not sure if this helps identify the cart type?

I ordered the Yewy UY1200Z charger. When I charge the pack and the charger goes into the CV phase( green light blinking) the batteries are bubbling pretty hard like boiling water, is that normal? I understand that is referred to as gassing but is bubbling pretty hard. Just want to make sure I'm not damaging new batteries. Thanks!!

Here is what the serial number lookup returns.
Make :TXT
Powertrain : Electric 36 V
Sub Model : TXT Standard (PDS)
Year : 2001

So you have a 2001 TXT-PDS that has been upgraded to 48V.

I don't have a manual for the Yewy charger, but CV (constant voltage) is typically used in the absorption stage in multistage chargers.

Bulk charge is typically CC (constant current) at the charger's max amps until the on-charge voltage climbs into the 2.35 to 2.40 VPC and then switches to the CV absorption stage.

In the CV absorption stage, the voltage is held constant and the amps are allowed to decrease down to about 1% to 3% of the battery's AH rating and then the charger switches to the CC finish charge stage.

In the finish charge stage, the amps are held constant (at a low flow rate) and the voltage is allowed to climb until it stops climbing. More correctly, the dV/dT meets the battery manufacturer's criteria. IE: US battery is 4mv/cell/hr, but Trojan does publish their dV/dT specs.

New batteries can gas a lot, so keep an eye on the electrolyte level.

I'd check the pack voltage and individual battery voltages while they are gassing hard. If the pack voltage is less than 65V and the eight batteries are all within 0.3V, I'd let them charge until the Yewy goes into float charge or 24 hours have elapsed.

[coosa]

Lots of great info in this thread, and I don't wanna derail it, but it seems like a good place to ask this question. I am in the process of breaking in a new battery pack, and the info on Scotty's site says to run the new pack down to 75% and then recharge. My question : does it hurt anything to recharge when I am only down to 90%, or even 95%?

I am recharging it everyday, and some days I just don't use it a lot. I've recharged it about 10 times so far, and I've gotten it down to 75% just once. I charged the pack last night and it's on 38.6 volts right now, so it seems like what I am doing is working ok, but it doesn't hurt to ask. Batteries are so expensive now that I want to get maximum use from them.

Thanks, and apologies to the OP for using his thread, but I suspect he can use the info too.

[Glade Rider]

Originally Posted by coosa

Lots of great info in this thread, and I don't wanna derail it, but it seems like a good place to ask this question. I am in the process of breaking in a new battery pack, and the info on Scotty's site says to run the new pack down to 75% and then recharge. My question : does it hurt anything to recharge when I am only down to 90%, or even 95%?

I am recharging it everyday, and some days I just don't use it a lot. I've recharged it about 10 times so far, and I've gotten it down to 75% just once. I charged the pack last night and it's on 38.6 volts right now, so it seems like what I am doing is working ok, but it doesn't hurt to ask. Batteries are so expensive now that I want to get maximum use from them.

Thanks, and apologies to the OP for using his thread, but I suspect he can use the info too.

No worries, all good questions.

[Glade Rider]

Originally Posted by JohnnieB

Here is what the serial number lookup returns.
Make :TXT
Powertrain : Electric 36 V
Sub Model : TXT Standard (PDS)
Year : 2001

So you have a 2001 TXT-PDS that has been upgraded to 48V.

I don't have a manual for the Yewy charger, but CV (constant voltage) is typically used in the absorption stage in multistage chargers.

Bulk charge is typically CC (constant current) at the charger's max amps until the on-charge voltage climbs into the 2.35 to 2.40 VPC and then switches to the CV absorption stage.

In the CV absorption stage, the voltage is held constant and the amps are allowed to decrease down to about 1% to 3% of the battery's AH rating and then the charger switches to the CC finish charge stage.

In the finish charge stage, the amps are held constant (at a low flow rate) and the voltage is allowed to climb until it stops climbing. More correctly, the dV/dT meets the battery manufacturer's criteria. IE: US battery is 4mv/cell/hr, but Trojan does publish their dV/dT specs.

New batteries can gas a lot, so keep an eye on the electrolyte level.

I'd check the pack voltage and individual battery voltages while they are gassing hard. If the pack voltage is less than 65V and the eight batteries are all within 0.3V, I'd let them charge until the Yewy goes into float charge or 24 hours have elapsed.

OK Scotty will do and thanks for all the technical info. Really appreciate it. I noticed the charger display showed the pack voltage at 60V while gassing hard and the voltage was dropping slowly. I will check the individual battery voltage while gassing hard on the next charge. I know the batteries "Gas" but the sound of boiling water made me nerves. Sounded like I was cooking the batteries but if this is normal then so be it. I stopped the charge this morning at 6:00 AM while in the CV stage (Flashing Green Light) and just tested the pack 8 hours later and the pack is at 51.8V and tested each individual battery and they are at 6.46V Just more info/data for review. Thanks again.