EZGO 2Five Lithium Conversion Question

[BobBoyce]

1. The wiring guages depend upon the application. I used 12 guage for the charger control wires, and 16 guage wires for the interlock wires.

2. You should not do without the reset/override switch, unless you plan to have someone with a tow rig or trailer follow you around or on call to come to you and drag it back home for you when it shuts down on you and leaves you stranded. Failures can occur at any time! You had better plan for it.

3. Yes, that is exactly what I did. I interrupted the black wire (AC hot) where it goes to the AC socket that the onboard charger plugs into.

4. I responded to your post about it on my other thread. And I also told you why it was a bad idea to cut the throttle off. Your cart will regen to a halt and be stuck where it sits.

Volt_Ampere, the onboard charger in the 2Five is never disconnected from the battery, as it is hardwired to it. The owners only option is to unplug the AC input cord from the AC input socket where the charger input socket would be on an RXV. So, interrupting the AC input is how you control the onboard charger on the 2Five.

Bob

[bernito]

Originally Posted by BobBoyce

2. You should not do without the reset/override switch, unless you plan to have someone with a tow rig or trailer follow you around or on call to come to you and drag it back home for you when it shuts down on you and leaves you stranded. Failures can occur at any time! You had better plan for it.

4. I responded to your post about it on my other thread. And I also told you why it was a bad idea to cut the throttle off. Your cart will regen to a halt and be stuck where it sits.

Bob

Thank you for all of your assistance Bob, I would not have had the confidence to tackle the conversions without it! I am sure I will have some additional questions along the way, but am ordering everything as we speak.

I live on a golf course, and only drive the cart around my neighborhood, from my house to the clubhouse and on the golf course. I can get towed by the club or one of my many neighbors who have carts. That said, I appreciate your caution as I am sure it will only cut off when the club is closed and nobody is home!

[BobBoyce]

Yea, it usually happens at the most inopportune time. At least it does for me. I live in the mountains where there is no outside help if/when things go wrong. I've had to get used to being self-reliant for a long time.

I'm a retired aerospace engineer, so I am used to thinking outside of the box when it comes to failure modes. That is why I design in redundancy and overrides for when you need to take manual control of automated systems. The simpler, the better.

[PingEye3]

Originally Posted by bernito

I am aiming for the simplest conversion using my existing on board charger. I read your RXV build thread and like the simplicity and low cost of using the pre-programmed 14 cell BMS. I have a few questions:

1. I would like to avoid having to wire the relay / charger control box to manage the on board charger. If I do not use a relay and use a 7 module leaf pack, which one of the lithium reprogramming profiles in the attached link would work best with the existing on board charger?

https://www.emf-power.com/product/de...q-programming/

2. Does the link you provided to the pre-programmed 14 cell BMS on ebay work as is (i.e. is “pre-programmed”) or do I need to make sure it is a specific version so it has the correct programming for a 7 module leaf pack?

3. I saw the BMS wiring diagram and was wondering if you had an actual picture of how you wired it before you covered it with the white plastic.

4. Can you confirm I do not need to use an SB120 connector and can just use 2 gauge terminal lug connectors to connect the battery pack to the controller (I would expect to need to upgrade the existing cables from the controller to the battery pack with 2 gauge cables)?

5. Do you recommend any specific bus bars and what did you use for the positive and negative terminals for the 2 gauge cables with the terminal lugs to attach to?

6. cgtech mentions “I hook the bms interlock up to interrupt the controller's throttle input.”. How does that change your BMS wiring diagram?

Sorry for all the questions, but want to make sure I get everything right.

Answering your question 1. If possible reprogram your charger to Profile #53 as the 58.392V cutoff is perfect for the pack. However, just as Bob said, use the relay with it for control by the BMS, even if you get it reprogrammed.

Question 5 - I use a bus bar identical to those connecting the modules which leaves the bus bar extended from the pack enough to connect the cables. See pic.

There's my 2 cents worth

[bernito]

Originally Posted by PingEye3

Answering your question 1. If possible reprogram your charger to Profile #53 as the 58.392V cutoff is perfect for the pack. However, just as Bob said, use the relay with it for control by the BMS, even if you get it reprogrammed.

Question 5 - I use a bus bar identical to those connecting the modules which leaves the bus bar extended from the pack enough to connect the cables. See pic.

There's my 2 cents worth

Thank you for your input. Do you happen to know the correct screw size for the center hole (between the negative and positive terminals) on the battery pack? My cells were shipped with screws for the positive and negative terminals, but not the center holes which I need to connect my BMS to.

[Sergio]

The middle terminal uses M4 x 16 screws.

[bernito]

Originally Posted by BobBoyce

Yea, it usually happens at the most inopportune time. At least it does for me. I live in the mountains where there is no outside help if/when things go wrong. I've had to get used to being self-reliant for a long time.

I'm a retired aerospace engineer, so I am used to thinking outside of the box when it comes to failure modes. That is why I design in redundancy and overrides for when you need to take manual control of automated systems. The simpler, the better.

I purchased a NTE Electronics DSDP Relay model R14-11D10-48, but it does not have any documentation except for the attached PDF. The diagram labeled D10 in the top left corner of page 2 (General Purpose Relays) shows the 8 terminals on the relay. They are not marked, so how do I know which terminal(s) are NO, NC, Com, etc. I believe:

1. Terminals 1 and 2 are NO (normally open)
2. Terminals 3 and 4 are NC (normally closed)
3. Terminals 5 and 6 are COM (common, so 1 & 5 and 2 & 6 yields NO and 3 & 5 and 4 & 6 yields NO)
4. Terminals 7 & 8 are 120V AC (power in)

[bernito]

Manufacturer provided the following information in case anyone purchases the same relay:

1. Terminals 1 and 2 are NC (normally closed)
2. Terminals 3 and 4 are NC (normally open)
3. Terminals 5 and 6 are COM (common, so 1 & 5 and 2 & 6 yields closed and 3 & 5 and 4 & 6 yields open)
4. Terminals 7 & 8 are 120V AC (power in, 7 is negative and 8 is positive)