Golfcart Lithium Upgrade

[paradise]

Needed to put some new batteris in my 22 year old 72v EZGO Medalist. So, per usual, instead of just going and getting the 9 8v batteries I need to hook it up the way it has been for the last 7 years, I decided we might as well give lithium batteries a shot . We are also putting in some new stereo gear, new onboard chargers, new custom wires, new main solenoid, reversing solenoid to replace mechanical FNR switch new body and cowl and repainting the frame and other components. thumbsup

I don't have any pics before we took off the body, but it looked like any other lifted white ezgo LOL. Only noticeable difference was the 3 additional 8v batteries in what used to be the bagwell area

Here is what it looked like after we took out the batteries and took the body off, 20+ years of dirt and grime, plus wires from multiple in place upgrades needed some major love...

Here is after pressure washing and throwing a first coat of paint on the frame...

We are working through wiring up the cells now (22 of them to equal ~72 nominal V). Best part is we will save about 500 lbs between the batteries and going from a metal body to plastic If I'm being honest, I'm not super happy to be going to a plastic body, but it was needed. There were some bodywork issues and EZGO no longer makes trim for the Medalist carts...

 

[Tank]

Wow!! That's beautiful.

What made you decide to go lithium. And a few questions -

How much were the batteries?
Did you have to get a special charger for lithium?
Advantages of going lithium? More power/speed? Longer charge?

Great work.

 

[Flying_Lavey]

Damn! That's a hell of an upgrade for a cart! What was the VA rating of the battery pack before vs now?

 

[lake p.a.l.]

Looks fantastic, great job. The terrain front cowl will rivet right on if you want a different look and the led lights for those are really good. Is the 72v system from Hi Performance Electric Vehicles?

 

[senorpdog]

Needed to put some new batteris in my 22 year old 72v EZGO Medalist. So, per usual, instead of just going and getting the 9 8v batteries I need to hook it up the way it has been for the last 7 years, I decided we might as well give lithium batteries a shot . We are also putting in some new stereo gear, new onboard chargers, new custom wires, new main solenoid, reversing solenoid to replace mechanical FNR switch new body and cowl and repainting the frame and other components. thumbsup

I don't have any pics before we took off the body, but it looked like any other lifted white ezgo LOL. Only noticeable difference was the 3 additional 8v batteries in what used to be the bagwell area

Here is what it looked like after we took out the batteries and took the body off, 20+ years of dirt and grime, plus wires from multiple in place upgrades needed some major love...
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Here is after pressure washing and throwing a first coat of paint on the frame...
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We are working through wiring up the cells now (22 of them to equal ~72 nominal V). Best part is we will save about 500 lbs between the batteries and going from a metal body to plastic If I'm being honest, I'm not super happy to be going to a plastic body, but it was needed. There were some bodywork issues and EZGO no longer makes trim for the Medalist carts...
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That looks like lithium boost's kit? I have that in my new ezgo it is the best thing I have ever done. The range is amazing and the no maintenance is easy. The only downfall is it makes the cart so much lighter it rides alot rougher but the thing is a rocketship. What size charger did you get? That would be the only thing I wish I went bigger on.

 

[Taboma]

Very cool, thanks for sharing and I hope you continue posting your progress and results :thumbsup

 

[paradise]

Wow!! That's beautiful.

What made you decide to go lithium. And a few questions -

How much were the batteries?
Did you have to get a special charger for lithium?
Advantages of going lithium? More power/speed? Longer charge?

Great work.

Battery kit w/ chargers and BMS was $4770
Technically with some kits you do not, but part of the reason I went with Lithium Boost was their chargers for each individual cell.
Flatter voltage curve as it is discharging, which effectively increases range and usability. There is also less internal resistance so they can output power at a faster rate (more acceleration, less voltage drop)
Biggest plus is they can be cycled 2000 times between replacements and no memory. Also, that little thing about no acid

Damn! That's a hell of an upgrade for a cart! What was the VA rating of the battery pack before vs now?

They were both 72V. Are you talking about the Ah rating? Technically the lead acid batteries were 225Ah and these are 100Ah, but they are rated differently so range should be the same or better.

Looks fantastic, great job. The terrain front cowl will rivet right on if you want a different look and the led lights for those are really good. Is the 72v system from Hi Performance Electric Vehicles?

Never heard of a terrain before this. Those are nice... Too bad I already have a TXT body on it's way LOL. Next time!

I had looked at HPEV, but couldn't find any reviews on them online. Found a fair amount about Lithium Boost and was under a time crunch so pulled the trigger.

That looks like lithium boost's kit? I have that in my new ezgo it is the best thing I have ever done. The range is amazing and the no maintenance is easy. The only downfall is it makes the cart so much lighter it rides alot rougher but the thing is a rocketship. What size charger did you get? That would be the only thing I wish I went bigger on.

Yes it is a Lithium Boost kit :thumbsup. I went with the smaller chargers, time will tell if that was a mistake or not. I was talking with them and they said about 6 hours for a charge which works with how we typically use the cart. Fingers Crossed...

I am worried about the ride too. I want to pull at least one of the leafs, possibly 2. I'll let you know how it works :thumbup::thumbsup

 

[senorpdog]

Battery kit w/ chargers and BMS was $4770
Technically with some kits you do not, but part of the reason I went with Lithium Boost was their chargers for each individual cell.
Flatter voltage curve as it is discharging, which effectively increases range and usability. There is also less internal resistance so they can output power at a faster rate (more acceleration, less voltage drop)
Biggest plus is they can be cycled 2000 times between replacements and no memory. Also, that little thing about no acid


They were both 72V. Are you talking about the Ah rating? Technically the lead acid batteries were 225Ah and these are 100Ah, but they are rated differently so range should be the same or better.


Never heard of a terrain before this. Those are nice... Too bad I already have a TXT body on it's way LOL. Next time!

I had looked at HPEV, but couldn't find any reviews on them online. Found a fair amount about Lithium Boost and was under a time crunch so pulled the trigger.


Yes it is a Lithium Boost kit :thumbsup. I went with the smaller chargers, time will tell if that was a mistake or not. I was talking with them and they said about 6 hours for a charge which works with how we typically use the cart. Fingers Crossed...

I am worried about the ride too. I want to pull at least one of the leafs, possibly 2. I'll let you know how it works :thumbup::thumbsup

Yeah the place I had mine installed has added a steel plate to the bottom of the cart to add weight

 

[paradise]

Yeah the place I had mine installed has added a steel plate to the bottom of the cart to add weight

lol that's hilarious. Kinda defeats the purpose of all this weight reduction [emoji14]

 

[senorpdog]

lol that's hilarious. Kinda defeats the purpose of all this weight reduction [emoji14]

Haha yes it does but at 25 mph I tended to catch air off of speed bumps

 

[RiverDave]

That is crazy nice!! For 5K though I think I might have just bought another golf cart?

I just sold my airbagged golfcart I had with new batteries, new charger, and more bells and whistles than you can shake a stick at for 4800 bucks.

RD

 

[paradise]

That is crazy nice!! For 5K though I think I might have just bought another golf cart?

I just sold my airbagged golfcart I had with new batteries, new charger, and more bells and whistles than you can shake a stick at for 4800 bucks.

RD

Don't forget this is 72v though. Twice the batteries as a 36v kit, so a 'normal' cart is $2500. If nothing else I was going to go with AGM batteries.

Besides this cart has sentimental value. This was the first cart I ever ran away from security with [emoji15][emoji3]

 

[warpt71]

Man I need some cash and fab skills, I have one running cart that needs a tune up and one that is a complete basket case. I have dreams though lol

 

[Tank]

That's awesome man. And yea it's a s spendy upgrade but seems to be well worth it. Can't wait to see how it turns out.

25mph is moving on a cart.

 

[paradise]

Little more progress. Trying to button up in the morning. Just have lights and stereo wiring. Plus 100 knick knacks lol

 

[X-rated]

Very cool!! Looks DCB rigged.

 

[Andy01]

Wow that is awesome, looks super clean as well. Does it charger fast than tradition?

 

[paradise]

Thanks guys! Cart is in tow all finished [emoji106]

 

[spectra3279]

What, it broke down already?

 

[paradise]

What, it broke down already?

All finished. Lol

Just edited my post. We are river bound

 

[paradise]

Final pics

 

[fishing fool]

Well??? How does it drive? Can you get air off a speed bump? Looks great [emoji106]

 

[paradise]

Drives great. [emoji106]

We took two leafs out of the spring pack today which helped a ton, but it is still stiffer than I would like for 2 people. I'll probably look into getting a custom pack made that is softer and has more arch to it.

Definitely wheelies easier than before, you can gas it at a roll and it'll lift the wheels [emoji15]. Brakes work better without all the weight too [emoji106]

Really impressed thus far, the voltage drop going up hills is so much less noticeable. I've got a smile on my face lol[emoji3]

 

[lake p.a.l.]

What 72v upgrade did you do?

 

[paradise]

What 72v upgrade did you do?

The only thing you really have to change to go 72v is the controller and batteries. For mine, It has a D&D beast motor, alltrax axe 7245 controller and we replaced the FNR switch with an SW202 reversing contractor [emoji106]

The battery kit I put in is from Lithium Boost

 

[bocco]

Can you explain the battery wiring? I see the straps to connect the batteries in series but then it looks like red and black wires connected to the same strap. Or can you post a wiring diagram? Just curious how this works.

 

[paradise]

Can you explain the battery wiring? I see the straps to connect the batteries in series but then it looks like red and black wires connected to the same strap. Or can you post a wiring diagram? Just curious how this works.

Sure, each of the batteries is in series like you said. That part is the same as a Lead Acid batteries, except we don't have 3 or 4 cells per 'battery', each battery is one cell. That's why there are 22 of them.

The red and black wires are for the individual cell chargers and BMS. basically, Lithium batteries are great but they are also 'fragile'. If you fully discharge them you turn them into very expensive grey bricks. Lol so to keep each cell perfectly balanced they have a charger for each cell that works completely separate from the others to make sure its cell is perfectly charged. In this way, even though they might finish at different times each cell is always charged to the same level.

On the flip side of that, the BMS manages the discharge side of things. It monitors the voltage of each cell and if any one drops to a low level it will give you a warning buzzer and then when they get to critical discharge level it will actually shut down the cart.

I want to draw up a diagram of this cart anyway so once I do I will post it up.

 

[bocco]

Sure, each of the batteries is in series like you said. That part is the same as a Lead Acid batteries, except we don't have 3 or 4 cells per 'battery', each battery is one cell. That's why there are 22 of them.

The red and black wires are for the individual cell chargers and BMS. basically, Lithium batteries are great but they are also 'fragile'. If you fully discharge them you turn them into very expensive grey bricks. Lol so to keep each cell perfectly balanced they have a charger for each cell that works completely separate from the others to make sure its cell is perfectly charged. In this way, even though they might finish at different times each cell is always charged to the same level.

On the flip side of that, the BMS manages the discharge side of things. It monitors the voltage of each cell and if any one drops to a low level it will give you a warning buzzer and then when they get to critical discharge level it will actually shut down the cart.

I want to draw up a diagram of this cart anyway so once I do I will post it up.

Wow, that's quite a setup. I actually looked it up on the Lithium Boost web site.

 

[lake p.a.l.]

Very sweet setup, congrats. I've done several 48 & 72v upgrades and the new lithium is fantastic.

 

[paradise]

Very sweet setup, congrats. I've done several 48 & 72v upgrades and the new lithium is fantastic.

Thanks!

 

[Ziggy]

Thanks!

Nice explanations too. [emoji106]
.
Until that last post I had been wondering if any motor changes had been at all.
Is it brushless?

 

[paradise]

Nice explanations too. [emoji106]
.
Until that last post I had been wondering if any motor changes had been at all.
Is it brushless?

Nope still an old school series brushed motor. It works great so no reason to upgrade yet

 

[Ziggy]

Nope still an old school series brushed motor. It works great so no reason to upgrade yet

Have you had to do any maintenance to it specifically?
The Wheeler Dealers rebuild of the electric Maserati was quite informative.

 

[Taboma]

These batts safe, beings as you're sitting on em ? :hotdevil

Great write up and explanations :thumbsup:thumbsup

 

[paradise]

Have you had to do any maintenance to it specifically?
The Wheeler Dealers rebuild of the electric Maserati was quite informative.

Nope. No issues but it certainly doesn't get that many miles. Lol

 

[paradise]

These batts safe, beings as you're sitting on em ? :hotdevil

Great write up and explanations :thumbsup:thumbsup

They are safer than the alternatives of years past, but there are certainly potential dangers. These are what is used (more or less) in all electric and hybrid cars so they have to be reasonably safe lol

 

[paradise]

Just thought I'd do an update on this, cart has been flawless since we brought it out. Range is killer (haven't been able to draw it down to the warning level yet)

Charge time seems really reasonable as well.

So far so good. If you're doing batteries and thinking about lithium, it's a lot of work for sure but it definitely seems worth it thus far.

 

[paradise]

Just thought I'd do an update on this, cart has been flawless since we brought it out. Range is killer (haven't been able to draw it down to the warning level yet)

Charge time seems really reasonable as well.

So far so good. If you're doing batteries and thinking about lithium, it's a lot of work for sure but it definitely seems worth it thus far.

I know there have been some questions about Lithium lately so I figured I would bump this.

Obviously the tech is way different than it was 7 years ago and this kit company is out of business but a lot of it is still relevant and these have been great since I installed them.

The main improvements we have enjoyed have been the 0 maintenance and longer useful charge life. Even on this old school, non regen Series cart we can't run them down in a day. In our AC cart that has Trojan Lithiums we haven't been able to run it down in a whole weekend LOL I can honestly say I haven't experienced any noticeable range decrease in the 7 years these have been installed.

Did I mention how great it is to not have to worry about battery acid maintenance and spills

 

[lake p.a.l.]

That's FANTASTIC

 

[Riverfamlee]

We put a Roypow lithium 105 Power series in our 6 seater. Recently did 22 miles and it still had juice in the tank!

 

[Havaduner]

Well, just to be different. I recently switched over to Lithium batteries as well. Couldn't believe how much better the cart rode and handled. Tried to do a bit of a mileage test, got a couple weekends cruising the park without status light moving off full charge. It finally moved down a bar (I think it has 5 bars) and then it quickly dropped down to "yellow". Plugged it in, nothing, no charge, status light on the BMS is holding steady red (not charging) Voltage is at 45volts. Went through some diagnostics over the phone, Tech guy is telling me the battery pack is toast. Going to drag it back from the river, have them take a look at it. I won't be replacing the battery pack, if it is done, I'll be setting the cart on fire!

 

[paradise]

Well, just to be different. I recently switched over to Lithium batteries as well. Couldn't believe how much better the cart rode and handled. Tried to do a bit of a mileage test, got a couple weekends cruising the park without status light moving off full charge. It finally moved down a bar (I think it has 5 bars) and then it quickly dropped down to "yellow". Plugged it in, nothing, no charge, status light on the BMS is holding steady red (not charging) Voltage is at 45volts. Went through some diagnostics over the phone, Tech guy is telling me the battery pack is toast. Going to drag it back from the river, have them take a look at it. I won't be replacing the battery pack, if it is done, I'll be setting the cart on fire!

Yeah unfortunately you can’t use a traditional voltage style gauge for lithiums. You need a shunt.

what batteries? The BMS would have turned it off before you hurt the pack.

Try a different charger too, your charger (if it’s just a golf cart charger) may see that voltage as charged. I have had the best luck with NOCO or Victron for Lithium chargers (on my other lithium projects). Tell us what battery(s) and we can help more.

 

[Badchoices03]

Here locally, there have been two golf carts that were recently converted to lithium, that caught fire while charging....one was caught and put out quickly, they other caused significant damage to the garage of the home....not sure of the details on the why they caught fire, but the info they had in common were both carts were older carts that had been recently converted...

 

[paradise]

Here locally, there have been two golf carts that were recently converted to lithium, that caught fire while charging....one was caught and put out quickly, they other caused significant damage to the garage of the home....not sure of the details on the why they caught fire, but the info they had in common were both carts were older carts that had been recently converted...

That’s a bummer. Definitely need to have the right equipment to do it right. Cheap battery/no BMS and the wrong charger = fire

 

[Badchoices03]

That’s a bummer. Definitely need to have the right equipment to do it right. Cheap battery/no BMS and the wrong charger = fire

Agree, the word was that they were both done by a reputable shop and that they should have had all the correct equipment...but I dont know anyone personally and don't know the details...

 

[Havaduner]

Yeah unfortunately you can’t use a traditional voltage style gauge for lithiums. You need a shunt.

what batteries? The BMS would have turned it off before you hurt the pack.

Try a different charger too, your charger (if it’s just a golf cart charger) may see that voltage as charged. I have had the best luck with NOCO or Victron for Lithium chargers (on my other lithium projects). Tell us what battery(s) and we can help more.

The system is from HPEVS in Ontario. They did the system on this cart when it was acid batteries too. Bill said the same thing as you, the BMS should have shut the system down, the tech guy is saying the pack is toast. I'll be dragging it back from Havasu again next week.

Here locally, there have been two golf carts that were recently converted to lithium, that caught fire while charging....one was caught and put out quickly, they other caused significant damage to the garage of the home....not sure of the details on the why they caught fire, but the info they had in common were both carts were older carts that had been recently converted...

I don't care what anybody tells me, I'll be charging my cart outside of the garage, and it won't be plugged in if I'm not there.

 

[Badchoices03]

The system is from HPEVS in Ontario. They did the system on this cart when it was acid batteries too. Bill said the same thing as you, the BMS should have shut the system down, the tech guy is saying the pack is toast. I'll be dragging it back from Havasu again next week.

I don't care what anybody tells me, I'll be charging my cart outside of the garage, and it won't be plugged in if I'm not there.

Thats what kind of kills it for me when it comes to lithium carts, my 72v cart with Delta Q charger is plugged in non-stop....never had any range problems for my use and I dont have to worry about my garage exploding from it..

I already have 3 electric bikes, and tons of RC lipo batteries that I have to worry about....lol