lifted club cars - lifted ezgo
Home FAQDonate Who's Online
Go Back   Buggies Gone Wild Golf Cart Forum > Modified Golf Carts > Extreme DC! > All things Lithium


Post New Thread  Reply
 
Thread Tools Display Modes
Old 07-10-2020, 03:00 PM   #11
DaveTM
Gone Wild
 
DaveTM's Avatar
 
Join Date: Oct 2012
Location: Southwestern Pa.
Posts: 6,204
Default Re: RoyPow Concern / Issue

Just my SWAG on this....as I'm pretty sure Sergio has provided you with sound advice.....but you say the Battery appears to be the "culprit" as it appears their BMS shuts down power output when under a heavy draw.

I looked at the RoyPow website and it states that the Maximum discharge is 130 amps. If that's the case your cart draws much more amps than that on an incline....albeit just for a short time period.

Plus you state that the + battery terminal gets hot.....that would seem to me that the controller is demanding AND drawing more than the maximum output the battery can deliver, and is set up for.

You should be able to adjust your controller to demand no more than the maximum output the batteries can deliver. OTOH, it would appear that the RoyPow you purchased is not adequate for golf cart purposes.

But again....I did not read the other thread that Sergio is referring to on your "fix." These are just amateur (Armature?) observations on my part.
DaveTM is offline   Reply With Quote
Alt Today
BGW

Golf car forum Sponsored Links

__________________
This advertising will not be shown in this way to registered members.
Register your free account today and become a member on Buggies Gone Wild Golf Cart Forum
   
Old 07-12-2020, 02:21 PM   #12
fstop
Gone Wild
 
Join Date: Oct 2019
Posts: 646
Default Re: RoyPow Concern / Issue

If you are seeing 62 volts you have a controller setting way out, or the controller is bad.

If this has been happening for a while (maybe w/out you being aware), this could potentially have caused some damage I would think, though 62v isn't way outside of the max charge voltage. It would certainly play havoc with the BMS.

I would think in addition, you likely need to reduce the max. current draw in your controller settings. At the very least, if you don't do that, you might want to avoid WOT up hills.

I think generally speaking, the more heat (current) the BMS (or the cells, or pretty much anything electronic) is subjected to, the less it's lifespan will be.

I have the same battery, but no hills, but use a Navitas controller with an AC motor. Knock on wood - no issues in the 6 months since I've had it. Put quite a few miles on it at this point. Nothing is ever even hardly warm under the seat (battery box or controller heatsink), and motor temps are also low.
fstop is offline   Reply With Quote
Old 07-13-2020, 09:18 AM   #13
jonr3
Gone Wild
 
jonr3's Avatar
Harley Davidson
 
Join Date: Jan 2016
Location: Hickory, NC
Posts: 702
Default Re: RoyPow Concern / Issue

Quote:
Originally Posted by Sergio View Post
Jonr3, as I mentioned back in the thread when you posted that information, Alltrax suggesting using 62v for overvoltage was extremely poor advice.
https://www.buggiesgonewild.com/show...0&post=1714100
I explained my reasons in post #91 why I thought that was the case, but apparently Alltrax disagreed, so perhaps the tech fro Alltrax can explain to us:

Why it is a good idea to allow the Alltrax XCT to raise the voltage during Regen to a level that far exceeds the maximum safe cell voltage for a LiFePO4 lithium chemistry cell.

What is the downside of setting it the "Max Voltage" to a safe value?
Sergio,
After reading that post I did lower the high voltage to 58.0. It didn't seem like it made much difference as the RoyPow would still shut down during WOT going up a hill. If I took my foot off the pedal, then the pack would come back up in just a couple of seconds.

The part I'm most concerned with now is how it will shut down for minutes at a time even though I'm not driving it very hard...
jonr3 is offline   Reply With Quote
Old 07-13-2020, 09:29 AM   #14
jonr3
Gone Wild
 
jonr3's Avatar
Harley Davidson
 
Join Date: Jan 2016
Location: Hickory, NC
Posts: 702
Default Re: RoyPow Concern / Issue

Quote:
Originally Posted by fstop View Post
If you are seeing 62 volts you have a controller setting way out, or the controller is bad.

If this has been happening for a while (maybe w/out you being aware), this could potentially have caused some damage I would think, though 62v isn't way outside of the max charge voltage. It would certainly play havoc with the BMS.

I would think in addition, you likely need to reduce the max. current draw in your controller settings. At the very least, if you don't do that, you might want to avoid WOT up hills.

I think generally speaking, the more heat (current) the BMS (or the cells, or pretty much anything electronic) is subjected to, the less it's lifespan will be.

I have the same battery, but no hills, but use a Navitas controller with an AC motor. Knock on wood - no issues in the 6 months since I've had it. Put quite a few miles on it at this point. Nothing is ever even hardly warm under the seat (battery box or controller heatsink), and motor temps are also low.
fstop,

I have a bright green voltmeter on my dash that is pretty hard to ignore so I usually notice any changes (and it's kind of fascinating to watch) so I don't think this new issue has been happening for a while. I am wondering if the problem is the controller (<2 years old) or the RoyPow and I'm trying to figure out how to test or verify which is causing the issue.

I did reduce the max current to below Sergio's recommendation and the pack would still shut off when going WOT up hills. So then I learned that I could just back off the throttle a little and it wouldn't shut down anymore. But this new issue is very concerning and I don't know what's causing it.
jonr3 is offline   Reply With Quote
Old 07-13-2020, 09:52 AM   #15
Sergio
Gone Wild
 
Sergio's Avatar
Club Car
 
Join Date: Sep 2012
Location: Charlotte, NC
Posts: 9,329
Default Re: RoyPow Concern / Issue

When looking at datasheets on line, it is important to understand the information being conveyed and notice the conditions for those specifications.

The LiFePO4 cells can "tolerate" overcharge and that is heavily marketed since it applies nicely to automobiles where you cannot avoid that condition.

It is not a "goal" or a "desirable" outcome You try to achieve and since you can easily avoid it by adjusting the settings on your XCT controller, that possibility should have been eliminated.

There is new research showing how much LiFePO4 cathode/anode gets eroded due to overcharge and the significant impact on its ability to deliver the rated capacity.

The "overcharge" specification also includes charging rate and temperature, both fall way outside of a "Regenerative" event where the current is much higher than your charger and the conditions when it happens often involve cells that are already someway stressed and hot due to the current discharge during periods of acceleration.

I posted that second rhetorical question to Alltrax (#10 post) for a reason:
What is the downside of setting the "Max Voltage" to a safe value?
There is about 1% capacity to be gained by charging LiFePO4 cells above 3.5v, so for folks that don't see a problem, please explain what are you trying to gain by intentionally setting your controller to operate in those conditions.

It would be nice if You knew what You are working with, but without any visibility of cell voltages or temperature sensor readings, it is very difficult to ascertain if you have a battery issues or maybe just a loose connection inside the box.


I see new members posting all the time that they can now "Resell" one of those packs to other members, perhaps one of them could provide some insight on how you should proceed as far as having your pack diagnosed.
Sergio is offline   Reply With Quote
Old 07-13-2020, 12:24 PM   #16
fstop
Gone Wild
 
Join Date: Oct 2019
Posts: 646
Default Re: RoyPow Concern / Issue

Quote:
Originally Posted by jonr3 View Post
fstop,

I have a bright green voltmeter on my dash that is pretty hard to ignore so I usually notice any changes (and it's kind of fascinating to watch) so I don't think this new issue has been happening for a while. I am wondering if the problem is the controller (<2 years old) or the RoyPow and I'm trying to figure out how to test or verify which is causing the issue.

I did reduce the max current to below Sergio's recommendation and the pack would still shut off when going WOT up hills. So then I learned that I could just back off the throttle a little and it wouldn't shut down anymore. But this new issue is very concerning and I don't know what's causing it.
I don't know if you can monitor battery current draw in real time with the Alltrax, but you should ascertain what it is when (or just before) it cuts out.

Slowing down during uphill should be limiting the current basically, so it sounds to me that it is still set too high - that's why you need to see what it is actually drawing. Would also be worthwhile to look at voltage right before it cuts out - if you are seeing below 50v and you have a 80% + charge there is significant amp draw.

The heat on the terminal is not normal. I'd venture a guess that there could somehow be a loose connection inside the box (since you say it is tight on the outside, where your cart cable connects), where the cable going to the BMS connects to that post that passes through the fire box case. There was a comment at one time a few months ago that a forum member heard of a RoyPow that had a loose terminal issue - don't know the details of it since he never responded to questions about further details or where he saw that information, but perhaps it is an issue that affects some packs.

Good luck and keep us posted on what you find out.
fstop is offline   Reply With Quote
Old 07-13-2020, 01:21 PM   #17
Bama Brad
Gone Wild
Mixed Breed
 
Join Date: Jul 2018
Location: Ramer, AL
Posts: 1,447
Default Re: RoyPow Concern / Issue

Jonr3, I would be concerned about that + terminal getting that hot...what is Roypow saying about this? How has been their response/concern? Let us know, I am following this closely.
Bama Brad is offline   Reply With Quote
Old 07-13-2020, 01:35 PM   #18
jonr3
Gone Wild
 
jonr3's Avatar
Harley Davidson
 
Join Date: Jan 2016
Location: Hickory, NC
Posts: 702
Default Re: RoyPow Concern / Issue

Quote:
Originally Posted by Bama Brad View Post
Jonr3, I would be concerned about that + terminal getting that hot...what is Roypow saying about this? How has been their response/concern? Let us know, I am following this closely.
On Friday, I emailed the dealer that I bought it from. He replied right back saying he forwarded it to RoyPow and will let me know as soon as he hears back from them.
jonr3 is offline   Reply With Quote
Old 07-13-2020, 08:26 PM   #19
jonr3
Gone Wild
 
jonr3's Avatar
Harley Davidson
 
Join Date: Jan 2016
Location: Hickory, NC
Posts: 702
Default Re: RoyPow Concern / Issue

Whatever it is, it seems to be getting worse. It died tonight for a few minutes and I was just putting around our flat yard at about 10 mph. Very, very frustrating.
jonr3 is offline   Reply With Quote
Old 07-14-2020, 06:31 AM   #20
BBBHC
Gone Wild
 
BBBHC's Avatar
Club Car
 
Join Date: Jul 2018
Location: Central Ohio
Posts: 1,720
Default Re: RoyPow Concern / Issue

Can you run a monitor session through your alltrax and log into a file? That should give much more information as to what is happening in these moments.

Sounds to me like whatever the problem is, it is degrading the batteries at this point.
BBBHC is offline   Reply With Quote
Reply
Go Back   Buggies Gone Wild Golf Cart Forum > Modified Golf Carts > Extreme DC! > All things Lithium


Thread Tools
Display Modes


Similar Threads
Thread Forum
Where to purchase Roypow? Electric Club Car
Anyone tried RoyPow lithium kit yet? All things Lithium
RoyPow battery tie down Lithium Club Car
Took the RoyPow plunge Lithium Club Car
RoyPow charging All things Lithium


All times are GMT -5. The time now is 08:26 PM.


Club Car Electric | EZGO Electric | Lifted Golf Carts | Gas EZGO | Used Golf Carts and Parts

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
This Website and forum is the property of Buggiesgonewild.com. No material may be taken or duplicated in part or full without prior written consent of the owners of buggiesgonewild.com. © 2006-2017 Buggiesgonewild.com. All rights reserved.