Total Cost Leaf RXV Lithium Swap

[pboehm21]

Curious to hear what everyone's total bills have come in for a lithium swap? I have a 2016 RXV that appears to be completely stock with the original Trojan batteries. They appear to be giving out so I'm contemplating doing the leaf or some other swap to lithium over the winter. The cart is primarily used driving around my neighborhood under 5 miles per day. I've priced batteries locally and prices seem to range from $720 to about $840 for 4-12v's. If I can go the lithium route for under $1000 I may do it. Will I be happy I did, given my scenario?

[Volt_Ampere]

I would plan at least 1800 to 2K for a Lithium swap.

[pboehm21]

Thought that might be the case. Looks like some new trojans might be in my future. Any other brands worth looking at?

[ejcox811]

I've got a 2017 RXV that has been sped up by Bob. It had original 4x12 Trojans with pretty weak range, so I was planning out a lithium swap. Just before my cells arrived, one of the Trojans bit the dust (sag to <10v under load, basically no range at all).

I did the conversion as cheap as possible now with thoughts of upgrading in the future. I bought the 7 pack G1 cells from TechDirectClub with BMS. I also bought 2 sets of bus bars and installed them under the PCB. I'm charging through the BMS but discharging straight from the pack. The BMS offers HV protection while charging but I currently don't have HV or LV protection while running with the exception of an audible buzzer integrated into the BMS that sounds on LV (maybe HV also, I'm not sure). I'm giving myself some room with charging to avoid HV on regen - only charging to 57ish volts instead of 58.6 max. Also checking pack voltage religiously. Occasionally checking individual cell voltage, but the BMS does a good job of balancing them on charge.

I've got a JLD404 w/ 75mV shunt that I'm installing to monitor pack voltage and track amps and AH while running. It also has configurable relays that you could use to disconnect pack on HV/LV (with relay/contactor), open throttle switch connection, or sound buzzer/warning lights. I'm going to use it to sound a buzzer and warning light on pack HV or LV conditions.

Also, I have the cheap Chinese BT BMS on order from AliExpress so I can watch live cell voltages and maybe set up the Sergio style relay protection (still undecided how I actually want to implement).

Anyway, I've been running the cart around the neighborhood for a couple weeks now. I think the lowest I've run the voltage between charges is 53.5v. The 15a charger charges it lightning fast also. Performance is incredible. No sag under acceleration, just power. Cart is MUCH lighter. Range is at least triple what I was getting with the tired old FLAs. Once I get the JLD404 hooked up I'll do some benchmark tests.

But back to the original question- cost:
Pack+BMS+hardware = $400
2 sets of bus bars = $20
Charger = $120
JLD404 = $62
Fuse, Terminal blocks, other misc. = $75

Total Cost = $677

Once I get the Chinese BMS and do some other upgrades and clean up it'll probably add another $100 or so. I just picked up an old truck bed toolbox for $35 to use the diamond plate aluminum to put a floor in the battery tray, now to just find the time...

https://www.techdirectclub.com/48-vo...-bms-lot-of-7/

https://www.techdirectclub.com/for-n...-and-5-busbar/

[PingEye3]

Ejcox811 - When you get around to chopping up the toolbox, attached is a drawing to work from. The bottom plate is easier when made out of a single piece. Sq tube spacer not needed if one piece bottom is made. There is the piece across the back and a small top for it. This helps to close off the rear from excessive water splashing. The other small pieces I make as needed when I do a Lithium upgrade. A couple of pictures for you.

[ejcox811]

Originally Posted by PingEye3

Ejcox811 - When you get around to chopping up the toolbox, attached is a drawing to work from. The bottom plate is easier when made out of a single piece. Sq tube spacer not needed if one piece bottom is made. There is the piece across the back and a small top for it. This helps to close off the rear from excessive water splashing. The other small pieces I make as needed when I do a Lithium upgrade. A couple of pictures for you.

This is incredibly helpful. Thank you! That's a very clean install.

Did you secure the aluminum to the plastic tray underneath? Also, what did you use to cut the aluminum? I'll have to make a 2-piece bottom as well since the width and height of the box are both less than 20.25". I just hope that my hack job looks half as clean as your setup!

[pboehm21]

Originally Posted by PingEye3

Ejcox811 - When you get around to chopping up the toolbox, attached is a drawing to work from. The bottom plate is easier when made out of a single piece. Sq tube spacer not needed if one piece bottom is made. There is the piece across the back and a small top for it. This helps to close off the rear from excessive water splashing. The other small pieces I make as needed when I do a Lithium upgrade. A couple of pictures for you.

That diagram is excellent! Thanks for sharing. If and when I go at this I hope mine turns out half as clean as yours.

[pboehm21]

Originally Posted by ejcox811

I've got a 2017 RXV that has been sped up by Bob. It had original 4x12 Trojans with pretty weak range, so I was planning out a lithium swap. Just before my cells arrived, one of the Trojans bit the dust (sag to <10v under load, basically no range at all).

I did the conversion as cheap as possible now with thoughts of upgrading in the future. I bought the 7 pack G1 cells from TechDirectClub with BMS. I also bought 2 sets of bus bars and installed them under the PCB. I'm charging through the BMS but discharging straight from the pack. The BMS offers HV protection while charging but I currently don't have HV or LV protection while running with the exception of an audible buzzer integrated into the BMS that sounds on LV (maybe HV also, I'm not sure). I'm giving myself some room with charging to avoid HV on regen - only charging to 57ish volts instead of 58.6 max. Also checking pack voltage religiously. Occasionally checking individual cell voltage, but the BMS does a good job of balancing them on charge.

I've got a JLD404 w/ 75mV shunt that I'm installing to monitor pack voltage and track amps and AH while running. It also has configurable relays that you could use to disconnect pack on HV/LV (with relay/contactor), open throttle switch connection, or sound buzzer/warning lights. I'm going to use it to sound a buzzer and warning light on pack HV or LV conditions.

Also, I have the cheap Chinese BT BMS on order from AliExpress so I can watch live cell voltages and maybe set up the Sergio style relay protection (still undecided how I actually want to implement).

Anyway, I've been running the cart around the neighborhood for a couple weeks now. I think the lowest I've run the voltage between charges is 53.5v. The 15a charger charges it lightning fast also. Performance is incredible. No sag under acceleration, just power. Cart is MUCH lighter. Range is at least triple what I was getting with the tired old FLAs. Once I get the JLD404 hooked up I'll do some benchmark tests.

But back to the original question- cost:
Pack+BMS+hardware = $400
2 sets of bus bars = $20
Charger = $120
JLD404 = $62
Fuse, Terminal blocks, other misc. = $75

Total Cost = $677

Once I get the Chinese BMS and do some other upgrades and clean up it'll probably add another $100 or so. I just picked up an old truck bed toolbox for $35 to use the diamond plate aluminum to put a floor in the battery tray, now to just find the time...

https://www.techdirectclub.com/48-vo...-bms-lot-of-7/

https://www.techdirectclub.com/for-n...-and-5-busbar/

That is an awesome write up... Thank you. Thats about what the numbers in my head were telling me but I wanted to make sure. How many hours do you think you have in the install?

[ejcox811]

Originally Posted by pboehm21

That is an awesome write up... Thank you. Thats about what the numbers in my head were telling me but I wanted to make sure. How many hours do you think you have in the install?

I got the battery put together and dropped in the cart in an evening, maybe 4 hours or so (including plenty of beverage breaks). Taking the old batteries out was my least favorite part. I was able to reuse my 2ga battery cables for everything I needed. When I go back to put the floor in, wire up the 12v accessory battery, and clean things up I'm sure I'll spend a whole lot more time.

One tip- take your time putting the battery together and take extra precautions not to short circuit while assembling. Also use insulated tools (or wrap with electrical tape like I did). I had a close call when a bus bar swung around and shorted out 2 cells. Luckily I was able to get it off right away, but I don't think it would take long to weld itself in place. That would've been ugly.

[Volt_Ampere]

I wish I had access to tools like that! I have a pretty good shop with many hand tools but nothing that can deal with metal work. I build model planes and guitars - neither require large machine tools. I can build anything electronic though.