Golf cart ; Lithium - ion battery

alan0043 · May 18, 2017

Hi Everyone,

I have an old golf cart in my barn that needs new batteries. I would like to get it up and running for the grand kids. I could also use it to help around the house. Or maybe take it with me on some camping trips. At the end of one of David's (Nuke-E) presentations, he showed a golf cart with a lithium-ion battery in it. RandyA was also at this year's ECR with his golf cart with a lithium battery in it. This got me started to think about my golf cart in the barn. Can I do the same thing. It is a dangerous thing for me to be thinking. lol. I did some searches on Google and also on You Tube. There is not to much out there on where the batteries came from. My question is the battery. I understand that the lithium batteries in cars are built in sections. Most golf carts run on 48 volts. I hope someone can point me in the right direction. Can I just buy a section that has 48 volts. I did some looking on E-Bay with not much luck. Or does someone know of a source for batteries that would work in the golf cart. My old golf cart run's on 36 volts. I have no idea what the lithium battery would cost. But if I want to get the cart up and going, I would still need to buy lead acid batteries. That would be 6 batteries at $75 / $100 per battery for a total of $450/$600. There might be a few more people out there wanting to hot rod their own golf cart.

How many amp hours is needed for the battery ?

What do you guys think,
Al

alan0043 · May 19, 2017

I am hoping that Nuke-E and RandyA will see my post.

Al

RandyA · May 19, 2017

Alan, my Club Car is 48 volts and as such has a DC motor controller rather than a "resistor coil ring" as the 36 volt Club Cars did a few years back. I am of the opinion from many postings I have read on the Buggies Unlimited form that one can run 48 volts on a 36 volt motor without damage. But, running the 48 volts on the 36 volt cart and the resistor rings may be "problematical". The 36 volt charger is also regulated through a "computer" on the cart (not in the charger) that will limit the charge voltage to the Li-Ion batteries unless a new charger is made. I've found that the OEM cart charger works OK but it is best to use a timer on the 120 side and limit the charge to no more than 2 hours, then check battery voltage. The ideal charge is 4 volts per cell (12 cells) and 4.2 volts per cell is considered max - anything over and damage to the battery can occur. The OEM Club Car 48 volt charger can reach over 54 volts if left on for any length of time. Most Internet articles I have read on the LI batteries say that recharge should be done when the battery reaches 45 volts and stopped at 48 and never over 50. There is NO voltage drop or sag with the LI battery like you get on a Lead Acid that begins to decay. It is power all the way down to 45 volts - which I believe could run a cart through 18 holes of golf. David believes it would be best to have two 48 V packs for 18 holes. I will most likely eventually add a second 48 volt pack to extend time/range if I can find a full T-pack in a junk yard to dissect. Not at all sure about other makes of golf carts - but I do have complete electrical schematics for older 48V and 36V Club Cars if needed. When I find time, I am going to make a new 48 volt charger with an Arduino as the controller's central measurement/regulating module.

I have not ventured into cutting open a 48V pack to remove 3 cells so as to have a 36 volt battery pack. But, I see no reason why it would be a big deal to make the change if you pulled out the three cells from the center section so as to leave the screw post and end plates. The tie bars for the cells are on top and accessible for cutting. If you did that you would end up with a left over 12V three-cell pack for other uses. Given the opportunity, I would like break one down into four 12V modules. Just don't not accidentally short + and - while going for a dropped wrench :rolleyes: . One other thing.... the cells are normally held together at the bottom by coolant tubes. Since I was not using the tubes and wanted a "tight" group of cells I inserted 1/4" threaded rod with fender washers through the tube holes on both sides and tightened down the nuts to pull the pack together then cut off the excess rod length. When received as is - it the bottom may look like a fan of playing cards as the cells are only joined at the top.

With those cautions - the swap is very easy and a blast! On a 48 volt cart you shed 320 pounds (each 8V battery weights 60 lbs or 360 lbs total. One 48 V LI battery is 40 pounds.) The weight loss alone gives a real boost in range, speed and power. I bought my battery as a single unit from an e-Bay seller for $340 plus $50 shipping. It was from a 2013 Chevy Volt, 48 V section, 2KW or 50 Ah rating. Much less than 6 new Trojans at $110 + tax ($700.00) plus I still have 4 good 8V Trojans and cores - 3 of which I am using to power a 24V inverter. If these links are still good, here are some on eBay as of today. If not, search on "Chevy Volt Batteries". Take care of the LI battery and, even with 5 years of age on a 2013, it will outlast a new set of lead acid batteries. Or, you can search auto salvage yards for a full LI T-pack from a Chevy Volt but expect to pay $1,200 to $2,200 plus even a core charge. If you can get a full pack as David did with the Battery Management System you can break it down and sell the extra batteries and not only pay for your cart batteries but make a profit. I am actively looking for a T-pack but it has to be the "right" price and hopefully with the BMS module. I found a 2013 pack locally for $1,700, which was not a bad price, but turned it down because I am a bargain hunter at heart. If you weren't there in person, read David's story on buying a full T-pack in his presentation from the ECR. It is well worth the time to do so.

Can't tell you anything about other types of LI batteries like from a Prius, but I understand they can be used in a similar manner. Maybe David can shed more light on junk yard LI batteries other than the Chevy Volt. IMHO, it is the best way to update a cart.

alan0043 · May 19, 2017

Hi Randy,

Thank you so very much for your reply. I was at this years ECR. I was also at David's presentation on batteries. That is what got me thinking about upgrading my golf cart with new batteries. I also was talking to you about your golf cart upgrade at your camp site. At that time I did not have any paper or pen with me to write down the details that I needed. So I thought it would be better to wait till I got home to ask some different questions. That is the reason why I start this thread about upgrading the batteries in a golf cart. There might be a few people also interested in this idea. By having details in a thread will be a big help to me finding the right parts that I need. If you find the right deal on a battery pack and want to sell a section or too, I would be interested. Before I buy anything I will get ahold of you to see if you find a battery pack that you will separate out it's sections. I am offering this idea incase you are thinking about separating out sections out of battery pack and wanting to sell them. I will also check out the link that you gave me about E-Bay on Volt batteries. I know I will have more questions later.

It also looks like the battery should have the BMS module. Is this true ? Or is there something else to use ?

Thank you again for your help,
Al

RandyA · May 20, 2017

OK - now I remember talking with you. There were quite a few guys at the rally that stopped by to talk about the LI conversion. I just lost track of who is who :rolleyes: . The battery I bought came with a connector for a BMS. While it is desirable in an electric vehicle to monitor and balance each cell in a much larger battery pack, doing so on a single 48 volt unit does not appear to be needed. You can quickly check each cell with a voltmeter if you want to determine if they are equal. Charging individual cells is possible but not something I plan on undertaking. Anyway, I have put some thought into building up a timer to count/cycle through each of the 12 cells and display the voltage on a single meter with an LED strip to show which cell is being displayed. This would be a read only unit - not a charging unit.

I hope I did not mislead you when I indicated that I was looking for a full T-pack from a Chevy Volt like David did. If I am able to latch onto one at a decent price I will most likely end up keeping and using the whole thing. I have a lot of lead acid and AGM batteries I would like to replace in the fiver, Volvo and my solar system now that I have a better understanding of the potential with the LI batteries. I thank David for taking the lead on using batteries from a Volt and sharing his knowledge/experiences. I probably would not have bought one and converted the GC if it were not for David's gracious sharing.

alan0043 · May 20, 2017

11 hours ago, RandyA said:

OK - now I remember talking with you. There were quite a few guys at the rally that stopped by to talk about the LI conversion. I just lost track of who is who. The battery I bought came with a connector for a BMS. While it is desirable in an electric vehicle to monitor and balance each cell in a much larger battery pack, doing so on a single 48 volt unit does not appear to be needed. You can quickly check each cell with a voltmeter if you want to determine if they are equal. Charging individual cells is possible but not something I plan on undertaking. Anyway, I have put some thought into building up a timer to count/cycle through each of the 12 cells and display the voltage on a single meter with an LED strip to show which cell is being displayed. This would be a read only unit - not a charging unit.

I hope I did not mislead you when I indicated that I was looking for a full T-pack from a Chevy Volt like David did. If I am able to latch onto one at a decent price I will most likely end up keeping and using the whole thing. I have a lot of lead acid and AGM batteries I would like to replace in the fiver, Volvo and my solar system now that I have a better understanding of the potential with the LI batteries. I thank David for taking the lead on using batteries from a Volt and sharing his knowledge/experiences. I probably would not have bought one and converted the GC if it were not for David's gracious sharing.

Hi Randy,

Thank you again for more information about the batteries. I was not mislead about the Chevy Volt battery, I don't think. I was just curious about how many of the sections you had plans for in a round about way. My thought process was if you had a section left over and wanted to sell it I would have been interested. The leads that you gave me about E-Bay is going to be a big help to me finding a battery section.

Is there any good forums out there talking about converting to lithium batteries ? My plan is to take my time with this project. Right now I have most of the summer for this project. My biggest project this next month is to finish up the rear lights on the truck.

David must be on the road some where. I have sent him an e-mail about wiring LED day time running lights on a Smart car, but I have not heard anything from him yet.

I still want to learn more about lithium battery conversions. What else should I read ?
Al

RandyA · May 20, 2017

A Google search may get you the most info. David did give me two links but I did not find much of need at the time and bookmark them. I believe David is still in Crossville. I have his phone number and will PM it to you.