07-01-2021, 08:23 AM | #31 | |
Gone Wild
Join Date: Jan 2013
Location: Saint Petersburg, FL
Posts: 2,089
|
Re: Lithium Pack Build Questions
Quote:
I know that people using the RoyPow pack with the 130 amp BMS are doing "fine" with amp draws as high as 200. When you turned your max amps down what did you turn it down to? My cart will pull 75 amps continuous just to maintain cruising speed and pulls a lot more getting up to speed. If you set your max amps to 130 then I can see why it barely accelerates. |
|
Today | |
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 |
|
07-01-2021, 10:32 AM | #32 | |
Not Yet Wild
Join Date: Jun 2021
Posts: 11
|
Re: Lithium Pack Build Questions
Quote:
Thanks Pat. I am a rookie at BMS stuff so I am kinda going off what I have picked up just trying to trouble shot my two carts. I am going to crack open one of the packs this weekend and see what brand the BMS is and see what the battery's look like. Is there a way to test and determine the AH rating of a pack?? I have already been in the pack as I bypassed the negative lead per the battery maker when the pack kept shutting off and I was headed to the river. The negative lead from the battery's runs thru the BMS and then to the Anderson connector. The BMS was cutting this connection when I pushed the throttle just a tiny bit. So I cut it off the BMS and connected it directly. Now the carts works but travels maybe 5 miles. Maybe different BMS work differently? Sounds like what your talking about bypasses the BMS altogether? I was under the impression BMS's over saw charging of the cells evenly as well as watched to make sure you didnt overdraw the batterys? I would like to see if I can use the cells in some configuration and possibly get a new BMS. I hate to waste them. I also have a 4 seat EZGO my daughters drive. I was big tires but the motor and controller are stock from what I know. Who would have thought battery's and golf carts would be so difficult.. |
|
07-01-2021, 10:47 AM | #33 | |
Not Yet Wild
Join Date: Jun 2021
Posts: 11
|
Re: Lithium Pack Build Questions
Quote:
Hi Bronson, One of the carts I am referring to yes is in the avatar. I had it built 5 years ago so some of the items are a bit vague to me. Here is some info. Tires are 23" Controller is one of the larger Alltrax SPM models. 48volt. Motor is a Spicer motor 012AJ3951 don't know about gear changes. I really would like to find a pack that allows me to pull as many amps as possible. I have a pretty steep hill I have to go up at the river. Normally we load the cart up coming back off the water and I would hate to have an issue every time we try and come up the hill.. The RoyPow packs might be a challenge even if they can pull 200amps? I can set my controller to 200amps and see how she drives. But after setting it to 400 amps and then back to 200amps I know I will not be happy.. |
|
07-01-2021, 01:33 PM | #34 |
Gone Wild
Join Date: Oct 2012
Location: Southwestern Pa.
Posts: 6,204
|
Re: Lithium Pack Build Questions
|
07-01-2021, 01:40 PM | #35 | |
Gone Wild
Join Date: Jul 2018
Location: Ramer, AL
Posts: 1,447
|
Re: Lithium Pack Build Questions
Quote:
|
|
07-01-2021, 02:40 PM | #36 | |
Gone Wild
Join Date: Oct 2012
Location: Southwestern Pa.
Posts: 6,204
|
Re: Lithium Pack Build Questions
Quote:
I know that I've hooked up a laptop to my Alltrax controller and found out that my cart demands (and got) 345 amps on the steepest hill I climb. My controller is a 650 amp so I adjusted the controller to "send" or "let thru" a maximum of 300amps even when the motor demands more. I've not experienced any degradation in performance and with that adjustment I believe I am squeezing out a little more run time. FWIW |
|
07-01-2021, 05:35 PM | #37 | |
Gone Wild
Join Date: Dec 2020
Location: Melbourne, Australia
Posts: 1,918
|
Re: Lithium Pack Build Questions
Quote:
The key switch line is also controlled by the BMS. On a low pack voltage or low cell voltage the BMS will disconnect the key switch, effectively shutting down the cart. The only thing that is being bypassed is the high discharge current cutoff but if your cells can supply the required demand, and you have an appropriately sized fuse or breaker, you’ll be ok. Cheers Pat. |
|
07-02-2021, 03:04 PM | #38 | |
Gone Wild
Join Date: Jan 2013
Location: Saint Petersburg, FL
Posts: 2,089
|
Re: Lithium Pack Build Questions
Quote:
If it is using lithium Ion and I assume is a 12S then I'd suspect the pack goes from 49.8V (4.15vpc) down to 39v (3.25vpc). I'm wondering if your low voltage cutoff on the Alltrax is set to 45V or 46V. If it is you can plug into it with your laptop and set it to 40V to see if you double your range. |
|
07-02-2021, 05:36 PM | #39 | |
Gone Wild
Join Date: Dec 2020
Location: Melbourne, Australia
Posts: 1,918
|
Re: Lithium Pack Build Questions
Booshy68,
Quote:
How long have you been running without the BMS connected? How many charge/discharge cycles? Your cells are probably unbalanced and your pack is only as good as it’s weakest cell, hence the 5 mile range. Hopefully you haven’t damaged cells. You can’t bypass the BMS without implementing the other measures that are described in the thread I linked to in post number 5 on page 1. That thread describes how the high current pass through is removed from the BMS but all protection functions are kept. Cheers Pat. |
|
|
Thread Tools | |
Display Modes | |
|
Similar Threads | ||||
Thread | Forum | |||
Looking for a new Lithium Pack | Lithium EZGO | |||
72V lithium pack? | All things Lithium | |||
Need Lithium don’t want to build Pack | Lithium EZGO | |||
Need a new lithium pack | Lithium Club Car | |||
Leaf Lithium battery pack/box build basic questions | All things Lithium |