09-05-2018, 12:09 PM | #11 |
Not Yet Wild
Join Date: Jun 2017
Posts: 44
|
Re: Bit the bullet Leaf Lithium build
i'll be subbed on this thread ...please post lot's of pictures !!!
|
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 |
|
09-05-2018, 03:29 PM | #12 | ||
Gone Wild
Join Date: Oct 2012
Location: Southwestern Pa.
Posts: 6,204
|
Re: Bit the bullet Leaf Lithium build
Quote:
Quote:
Mounting options that I am considering is #1-1/8" Aluminum sheets to form a box, #2-1/8" Steel sheets to form a box. I have a nephew that can weld steel. #3-5/8" plywood. The plywood option is not my top choice as I go thru a lot of water 'n mud. I'm considering "lining" the battery box with plexiglass to keep mud and water out. Then mount the battery box inside that enclosure....if you get what I'm saying. My current thoughts are on which BMS system I should get. There is one from ZEVA and another from Chargery. I'm researching these now to make a decision. |
||
09-05-2018, 04:42 PM | #13 |
Gone Wild
Join Date: Sep 2012
Location: Charlotte, NC
Posts: 9,329
|
Re: Bit the bullet Leaf Lithium build
You may want to double-check those voltages before you order a charger and configure your BMS.
Those Gen 1 Leaf modules have 4 x 30AH cell pouches connected as 2 series of 2 parallel cells. The nominal useable cell range is 3.65v to 4.2v, but is recommended to stay below 4.1v/cell. That gives you a usable voltage range of 51.1v to 57.4v. You can go lower than 3.65v, but You may want to look at the discharge graph for those cells, the "knee" on the curve becomes really steep below 3.65v and the voltage comes down pretty fast. |
09-05-2018, 04:56 PM | #14 |
Getting Wild
Join Date: Aug 2017
Posts: 94
|
Re: Bit the bullet Leaf Lithium build
Quote:
|
09-05-2018, 06:01 PM | #15 |
Gone Wild
Join Date: Jan 2013
Location: Saint Petersburg, FL
Posts: 2,089
|
Re: Bit the bullet Leaf Lithium build
Dave, I think you may be talking about the nominal voltage per cell.
3.7 vpc (x2 for 7.4vpc) is a common nominal lithium voltage for a cell that maxes at 4.2 vpc. Watch your upper/lower limits based on your chemistry. I don't have Leaf cells so I don't know your chemistry but Sergio sounds like he does with "3.65v to 4.2v" x2 that would be 7.3v per module up to 8.4v (8.2v if you want to be safe) per module. 7 of them would give you 51.1v to 57.4v (or 58.8v if you charge to max). |
09-05-2018, 07:12 PM | #16 |
Gone Wild
Join Date: Oct 2012
Location: Southwestern Pa.
Posts: 6,204
|
Re: Bit the bullet Leaf Lithium build
CELL SPECIFICATIONS
Cell type..................Laminate type Cathode material......LiMn2O4 with LiNiO2 Anode material.........Graphite Rated capacity..........(0.3C) 33.1 Ah Average voltage........3.8 V Length.....................11.417" (290 mm) Width.......................8.504" (216 mm) Thickness..................0.2795" (7.1mm) Weight......................1.7624 lbs (799 g) BTW.....Maximum voltage is 4.2V per cell. (Thus 8.4V per module) And yes, the low voltage number......which I don't have in front of me, I will know prior to the configuring of the BMS. I do know that going to low will kill the battery. I believe the low voltage cutoff is 2.5V per cell. (Battery University) I will need to confirm what the "best" low setting is for cutoff. |
09-05-2018, 09:51 PM | #17 |
Gone Wild
Join Date: Jan 2013
Location: Saint Petersburg, FL
Posts: 2,089
|
Re: Bit the bullet Leaf Lithium build
From what I understand the methods of killing a lithium battery are going too low on voltage, going too high on voltage, discharging faster than rated (and building heat), storing in too high a heat and charging with too much amperage (regen braking).
I don't know where you live, but ambient temp is something you often just have to deal with. The rest you have control over. It's just knowing the limits of the pack, adding a safety margin and staying within that. Having said that, it really isn't that difficult... I had my Li batteries for months before I made the switch and really am amazed at how easy it was now that I look back. All the stuff I was worried about were complete non-issues. My biggest problem was getting past my own incorrect, pre-conceived notions about lithium! |
09-06-2018, 04:55 AM | #18 |
Gone Wild
Join Date: Oct 2012
Location: Southwestern Pa.
Posts: 6,204
|
Re: Bit the bullet Leaf Lithium build
I agree with you 100%. On my cart, regen is a non-issue as I don't have that "option" on my cart. (Brakes are required on any downhill....it's all free-wheeling!!)
The overcharge is controlled via charger settings and the undercharge is controlled via killing power to the key switch using an interlock circuit once the undervolt cutoff setting is reached. For my area, Southwest Pennsylvania, the hottest temps that I will be dealing with is high 80's (when hotter I just don't go out) and the low's can be in the high teens....but usually in the mid 20's to high 30's in "hunting season." FWIW I believe I have the basic understanding to build this system and make it safe....or I would not do it. That being said I will still post questions that at face, may appear dumb......but I ask the same questions (at times) more than one way so that my understanding of the issues is complete....or at least for me. I'm not even close to being an engineer. My "trade" was CPA\tax. Math I can do.....understanding comes to me via visual drawings with reading more than just reading. Unless it's tax code!! |
09-06-2018, 07:44 AM | #19 |
Gone Wild
Join Date: Oct 2012
Location: Southwestern Pa.
Posts: 6,204
|
Re: Bit the bullet Leaf Lithium build
Further research.....(AKA Ask BobBoyce via PM) and he states the high end should go no higher than 4.2V and the low end 2.7V. Totals are 37.8 & 58.8.
These parameters will provide the most longevity from the Leaf batteries. |
09-06-2018, 07:55 AM | #20 | |
Getting Wild
Join Date: Aug 2017
Posts: 94
|
Re: Bit the bullet Leaf Lithium build
Quote:
I will be following this one closely to see how you end up installing them. I hope it works out great for you |
|
|
Thread Tools | |
Display Modes | |
|
Similar Threads | ||||
Thread | Forum | |||
Lithium Conversion (leaf battery) | Lithium EZGO | |||
Club Car Onward Leaf Lithium conversion | All things Lithium | |||
Lithium Nissan Leaf conversion x 2 | Lithium Club Car | |||
Bit the bullet and doing a cheap build on G9/G2 | Lifted Golf Carts | |||
Bit the bullet: G2 420cc Predator Build | Clone Engine Swaps |