I saw a post in the SD golf cart FB page where someone was asking about converting four early model GEMs to lithium and it’s looking like people have been going to a local battery shop in El Cajon which puts in LiFePo4 batteries and a charger. The thing is, LiFePo4 is NOT what you want in a GEM or even a street legal EzGO cart since their max output current is so low… Put people are doing it and since their previous batteries sucked, they probably think it’s cool. yikes.
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Yep, I helped a guy through some issues with one of those kits. I should check up on him to see how he is doing. I kinda lost track of the guy. Once they are off and running they just stop responding to messages.
Like you said, their other (lead) system was so bad that they don’t know that these are not good either. It actually kinda works… at least for now.
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Cool. Darwinism will soon strike down bateries too.
I’m confused. LiFePo4 is the same thing as LFP, no? Apparently Lots of regular EV manufacturers are switching to this battery chemistry. If it works for a regular EV, it should work for a GEM, no? What am i missing?
I’m in the early stages of figuring out a lithium conversion for my 2011 eLXD lead snailmobile so it is more than just curiosity.
The problem is that the group here has messed around with this chemistry a few years ago and found it doesn’t last long. Sure it works for a while when first installed, but quickly drops off after a few years. It is our opinion that Lifepo4 is good for light loads like RV’s and solar/backup power but does not have the capacity for EV use. Running them hard kills them.
Ask yourself why the major car manufacturers are not using Lifepo4. I see the article is quoting Tesla is offering it now(which I did not know) but dougl has a good explanation as to what they are up to and how below.
It is a larger package. it involves a complicated install. The drop in “kits” offered involves multiple units to get required capacity and voltage.
It is important to monitor these batteries at a cellular level with a BMS. Many/most manufacturers have figured this out but usually do not offer access to the info or battery status. I see that the better units are now offering BTooth monitoring but not much control over what is going on. (This might be a good thing for most users as they wouldn’t know what to do with the controls if they had it).
BUT- when you start chaining multiple BMS units together it sets up for a few different scenarios of failure due to the BMS units are not aware of each other.
Not saying you can’t go out and try a set. This group is all about experimenting and pushing the boundaries of what these cars can do in an effort of making them fit our expectations.
Spend some time poking around in the archives and you can find people that have gone down the wild paths and come back with mediocre results. We all like to learn from each other. We also try to keep others from making unnecessary (and costly) mistakes.
what you are missing is the fact that the auto manufacturers are matching current output to match the required demand. ie they put the correct number of modules in parallel so the max output matches the vehicle demand. But look at the max output of what’s getting put into NEVs and you’ll see they are using 12V modules with ~100A max current so they would need 2 or 3 sets in parallel to not only provide what the vehicle needs for decent acceleration but also this is needed to not stress the batteries. a 100A battery with a low resistive load wanting 300A will push that little batt to it’s limit and stress it…
Looking closer at the specs, one 72V battery has an 80A max continuous rating so even with 2 of them in parallel(which it sounds like what people are getting) provided 160A MAX continuous(more than a few seconds). So a e2 would likely need at least 3 to not get close to running at max capabilities and an e4 and e6 would likely need 4 if you wanted them to last. But, 2 will move your cart better than lead but will be stressing lithium batteries and shortening the battery life.
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What I noted about that BB package was as suggested → running two 72v in parallel config. This install was an early Gen1 car with one battery in front and one in back under the seat.
Potential issues:
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In theory this produces a package that will not draw from both batteries evenly. Front battery has shorter cables being closer to the controller.
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This battery has a neat little monitor built into the battery and a pushbutton to turn it on and off. No BTooth. When hooked up in parallel, First pack is turned on and the BattV lit up as expected. Went to switch on the second pack and it was also showing V!!! Was the BMS ON? Assumed no so we pushed the button. No change. We couldn’t tell without unplugging it. It does have a nice Anderson Connector for doing this exercise.
– So- if one battery has an issue and shuts itself down it isn’t obvious as to which one is having the issue. Hopefully BB has noticed this and will correct this. -
BB twin package is only 54Ah. Not much more than a nice LA pack. $2500 with a charger might be suitable for some people.
Not! Most if not all use NMC.
The work and testing has been done.
Go with proven NMC Samsung 22s SDI battery.
I bought a MM from you Dave and it works great. A couple questions. What are the dip switch settings? next question; I am going Lithium and am switching the Zivan to a lithium programmed Delta Q. I get where to attach the black, white, and red wires plus no attaching the green to anything. Are the white and black on the round harness are the same as the white and black on the Delta Q? Also, what about the other two wires coming from the Zivan next to the round harness? What do I do with those. You are the KING!
Hey @SURFGUYGLEN,
Welcome to the group.
What lithium pack did you install?
The old round plug from the zivan is no longer used. The white is actually going up to the LED on the top of the dash and the black is the old temp sensor for the batteries. If your old charger is still working you can nicely pull the wires back and send them off with the old zivan to it’s new home. Or you can cut them off and be done with it.
The other two wires (probably a green wire and a red with green stripe?) will be your interlock wires and they need to be connected together or your car will not go.
Or LiFePo4?
Yes, I don’t recall!
I think everything has been answered,
Tesla is Testing LFP batteries in the Cheapest and Slowest model 3 because the discharge rate is lower than nmc
Also, they have a single BMS that monitors the whole pack.
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I think everything has been answered
Sky being blue is still hanging there.
Also- Why is it that we are surrounded by planets named after GODS and we live on one named after DIRT? Who is responsible for that one?
To save money? Or is there something new?
I have a feeling to meet demand from Chinese supplier.
Chevy Spark used LFP for a year or two before going lithion.
I am using 3 24 volt 100ah batteries in a custom enclosure. MFG says ok to run in series.
Thanks for the help. I’m going to sit down, scratch my head and map out old wires and new wires and then I’ll run it by you again to see if I got it right.
@SURFGUYGLEN - Who have you been talking to?
Did you already buy these batteries?
I’m guessing the charger is coming from the same source?
I did buy them already. From Amazon. I am getting the charger from Battery Pete
Am I going totally the wrong direction here? I know I am going to have to build a custom enclosure for the batteries but the price was right. I ordered a new charger with programming specific to these batteries. I can still return the batteries if I need to.