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Discussion Starter #141
Bms16t pics. I opened the BMS enclosure to see the quality of the circuitry - seems okay. The only observation so far - no mounting lips on either BMS or the monitor. Also I haven't quite figured out how they're balancing at the high current they're claiming - I don't see any beefy resistive components.
 

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Okay An update! Got the new machine finally (new to me, 2014). Had the original batteries. Pulled them and the corroded to death battery trays. Pressure washed the hell out of it. Amazon will bring me the chemicals to make the frame acceptable again. For those who don't know there are a pair of 2A fused pigtails (in the pic with my hand) that connect to the + post of the most negative battery. These are there to give you 12v Standby power (think the clock on a radio). By their nature they unbalance the pack. So I peeled the harness apart back to the controller and removed both. I left the wires otherwise, in case there's ever a need. Also pulled the lower skid guard off to clean out 20 lbs of mud!
 

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Then I set the lithiums in place. Since they are the latest and greatest from the automotive world, they provide 11.7KW in a footprint about the same size as two of the old lead acid batteries. Two points:
  • The batteries will be fully enclosed and will have active cooling
  • As these are NMC and not LiFePo4, they are about half the size for the same capacity
Still deciding on an aluminum battery box (with clear lid) or all plastic (polycarbonate). Metal is easier for me to work with and stronger. Plastic is a better electrical and thermal insulator.

BMS: Up in the air still. I know I need at least 200ma of balancing current if its not active balancing. But up over an amp would be better. At high charge rates, high balancing current is critical so one cell doesn't overvoltage. There is a quick youtube video on tesla cells balancing. At low SOC, they are off by over 30mv. With high charge currents one cell is bouncing as high as 4.202v. They also use 4.200 as the full charge voltage so its not way high, but I want to stay very even. I also want a bms that will run an external SOC display or give me that data via bluetooth. I love data!!
 

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Discussion Starter #146
Oh and weight. These weigh 19lbs each. So total pack will weigh 550lbs less than lead acid!
My current pack is 80lb (5kW). What I've noticed, while it makes it nice and snappy on even terrain, loss of ballast on trails with sideways incline makes it less stable and actually top heavy. I even entertained an idea of having removable ballast of some kind for use on that kind of terrain. Might eventually just build a bigger heavier Lithium pack and also put a decent inverter in for running power tools.
 

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My current pack is 80lb (5kW). What I've noticed, while it makes it nice and snappy on even terrain, loss of ballast on trails with sideways incline makes it less stable and actually top heavy. I even entertained an idea of having removable ballast of some kind for use on that kind of terrain. Might eventually just build a bigger heavier Lithium pack and also put a decent inverter in for running power tools.
Might want to consider 1" or even 2" wheel spacers to wide stance might help with COG.
 

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Worked on the box today. Using .080 aluminum and rivets. I entertained the idea of bent corners and welding it but I don't have a tig (or a press brake) and I'm not spending $300+ for welding and bending. I'll seal the seams and insulate the inside and then tape the seams of the insulation.
 

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This thread is where all member discussion of self designed and assembled Lithium conversions will be placed. It is explicitly understood that the ideas, concepts, designs and assemblies of components are not from commercial sources and may not be the result of professional engineering or persons with extensive understanding of the chemistries and mechanics involved. RangerForums.net will not be responsible for any result or outcome impacting members who apply the ideas, designs or concepts expressed by forum members in this thread.
 

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This thread is where all member discussion of self designed and assembled Lithium conversions will be placed. It is explicitly understood that the ideas, concepts, designs and assemblies of components are not from commercial sources and may not be the result of professional engineering or persons with extensive understanding of the chemistries and mechanics involved. RangerForums.net will not be responsible for any result or outcome impacting members who apply the ideas, designs or concepts expressed by forum members in this thread.


Great idea Jack


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Worked on the box today. Using .080 aluminum and rivets. I entertained the idea of bent corners and welding it but I don't have a tig (or a press brake) and I'm not spending $300+ for welding and bending. I'll seal the seams and insulate the inside and then tape the seams of the insulation.
Any updates?
 

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Hey all, just watched a video on these used Lithium batteries and wondered if they would work in our Ranger ev's?

 

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In my humble opinion, they will work very well as your power source.

You will need to get your charger reprogrammed for these cells (or buy a new charger if it cannot be reprogrammed). And of course, you will need to bolt them down solidly, wire the 2 packs in series, etc.

The fuse on your Sevcon should work fine with this new power source. Since 3.0V per cell is empty, FLAT (which you should likely avoid)... your battery gauge will read around 48V for empty so the SOC gauge will be a LOT misleading.

My Ranger has the typical surging or hesitating when the battery voltage drops below ... I think it is 42V .. under load. These cells should be stiff enough that they do not show that problem unless you have a connection really loose!

Too bad they only ship to the lower 48!
 

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Oh and weight. These weigh 19lbs each. So total pack will weigh 550lbs less than lead acid!
The EV I put drop in lithium batteries in lost 520#. It rides stiff and the front end suspension very noisy when in rough terrain.


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Have you reduced tire pressure to adjust for less weight? I'm running my Ranger EV Li at about 10 PSI.
Yes that did help. My 2014 w the 200ah Voltronixs kit lost 480#. It’s not as noticeable as the drop ins. I really don’t have any balance issues as far as top heavy but I do have 1” spacers on the front mainly to keep the tires away from the tie rod ends


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