Tom Haeder-Lithium batteries in Polaris Ranger EV 

Enjoy your Ranger EV. We love ours and use it every day on our acreage. The electric system did exhibit some idiosyncrasies during extremely cold weather over the last couple of weeks (mid January 2024). Temps were sometimes below zero or 10 degrees or so. The batteries seemed to refuse to charge, even in the garage where the temp was down to 11 degrees at times. The electrical drive system would kick out when driving in really cold weather. If I would coast downhill or even when I decelerate to stop, it would kick out. Then I'd have to put the speed switch in N (neutral) and turn the key off and wait to hear the click in the Polaris system and then put the switch into F or R and it would drive fine until the next time it would kick out. All these problems went away when outdoor temps got up to about 20°-30° F.

Hi, thanks for your comment / question Be sure to watch a follow-up video I released entitled “Tom Haeder-odd polarity reversal of LIFPO batteries in Polaris Ranger” The components I bought are as follows: Dakota Lithium 48V Golf Cart Battery Set - 60+ Miles I ordered directly from Dakota Lithium. I must have called them on the phone (can’t remember) and ordered with my credit card. This morning I used Google to search for Dakota Lithium 135 amp hour battery and it appears one can buy the batteries individually but I ordered the kit that is for a golf cart. The kit came with the 4 batteries and two 12.8 volt chargers and a 48 volt charger. Digital voltmeter The previous owner ordered this and I have no other info on it. Momentary push button switch I bought that at a local big box store (Menards, I think). Stainless steel threaded rods (Amazon) M8x250mm Fully Threaded Rod Studs Long Metric Threaded Screw 304 Stainless Steel Right Hand Threads All Threaded Rod Studs for Anchor Bolts Clamps Hangers U-Bolts 2 Pack Best of luck, Tom

Is the H M L selector just a setting on the controller or is it actually different gearing?

Your EV died, probably because you were demanding more amps than your BMS is capable of discharging, thus, the BMS shut the battery off.

I think it's probably just changing settings on the controller but don't know for sure.

You are probably right. It has happened again, when a friend was using the Polaris. He didn't know he should not have used the high speed setting. It stopped, he shut it off using the key, he turned the key back on and it went again. That indicates it was not an overheat problem, because it apparently reset immediately with the key shutoff. Thanks for your input.

Thanks for your comment, Kirk. I think you are right, although I don't know too much about the BMS function. I contacted a customer service person at Dakota Lithium, hoping he might know an engineer at Polaris and could consult with them about this problem, but the he said it is probably the BMS limiting demand from the batteries. He suggested I experiment with limiting the travel of the accelerator pedal. I haven't tried that yet. Perhaps there is a screw adjustment for the pedal. Of course, if I limit pedal travel, that will limit speed in all modes but I wouldn't necessarily care because. when I want to go fast, I'd use the H mode with limited travel. Presumably that would still be faster than with full pedal travel in M mode. Have a great 2024, Tom.

Thanks for the comment, Richard. I think it was the folks at Dakota Lithium that advised me that the onboard charger would only charge up the lithium batteries to a voltage that is somewhat below their full potential. Recently a friend of mine unknowingly plugged in the old onboard charger after driving my Polaris. I noticed it right away and disconnected the onboard charger for fear the charging rate would be too high for the lithium batteries. As I understand it, the lithium batteries are 12.8 VDC but lead acid batteries are 12 VDC. But most lead acid batteries are charged at 14.4 VDC so I don't know why the 14.4 volts wouldn't charge the lithium batteries to full potential. A couple days ago, I was driving my Polaris and pulling a light trailer. I decided to use the "H" (high speed) mode and just modulate the pedal so as not to go full speed. I had learned that using the H mode might eventually kick out the BMS in one or more battery and then the Polaris stops. In the past, the Polaris would return to normal if I turned the switch off and on again. This time the Polaris was dead and I got pulled home. I used my voltmeter and discovered that two of the 4 batteries had reversed their polarity. I disconnected all the battery cables and then all four batteries had positive polarity so I reinstalled the cables and then the Polaris functioned normally again. I think the BMS (Battery Management System) in each lithium battery is somewhat intolerant of the regenerative dynamic braking in the Polaris EV. I might make a RU-vid video on this recent experience. Best of luck when you change to lithium. Other than a few little idiosyncrasies, I am well pleased with the LIFEPO batteries.

Tom, Your experience with installing Lithium batteries on your Polaris EV is of great interest to me. The lead-acid batteries in my Polaris are weak and I sometimes have trouble getting back to the house after checking the cattle. I want to upgrade to lithium batteries and am currently gathering data in deciding which way to go. I watched a RU-vid video on the installation of a Sun Fun lithium kit on a Polaris EV. In the video, the installer said the batteries were designed to be exact replacements for the lead acid batteries. The video title is: Polaris Ranger EV 13.6 kWh / 14 Horsepower Lithium Battery Upgrade - Sun Fun Kits LLC. Using the original battery with the lithium batteries will make the installation process much easier. As I mentioned, the Polaris charger has several charge profiles. There are 10 different profiles for various battery types but I’m not smart enough to know which profile would work best with lithium batteries. Maybe the Sun Fun kit people will know. The small 48 V charger that came with your batteries looked small - especially compared to the original Polaris charger. You mentioned how long it took to recharge your batteries with the charger. I wonder if the BMS that's built into your batteries will protect the batteries from over-heating from a higher amperage charge that would be provided by the original charger? I hope you find out why your batteries are cutting out under load. I can’t imagine how the regenerative dynamic braking in the Polaris EV could cause the problem. The charge current from the regenerative braking should not be very high. I suggest you call the battery company and get help in solving your battery issue. They should know why the batteries are shutting down. My guess is the problem is with the BMS. I encourage you to make another video about the battery shut-down problem so that hopefully someone will suggest a fix.

@@rossooner-123 Thanks for your comments, Richard. The original on-board charger in the Polaris did charge much faster than the new charger that came with the lithium battery kit but I plug the Polaris in after every use and the slow charging has been no problem at all. I knew the on-board charger had many charging profiles and I did change the profile a couple times, trying to prevent boiling the water out of the lead acid batteries. I suppose one could try plugging in the on-board Delta Q charger for a fast charge and then top it off with the charger that is lithium battery compatible. That is, if the lithium batteries would tolerate a fast charge rate. I do plan to make a RU-vid video on this latest BMS problem, and I do plan to contact the battery supplier about it too. The battery supplier has great tech support and Polaris doesn't. The Polaris dealerships seem to know very little about the Ranger EV electrics.

@@rossooner-123 Hi, Richard. I finally got around to publishing a new RU-vid video showing the most recent problem I have had. This is the video you encouraged me to create and send to the battery mfg and maybe to Polaris. I'll send it to the battery mfg and maybe they know some engineers at Polaris and together they could come up with a solution so customers like me could run their electric Polaris Ranger at full speed in the "H" mode (high speed) and not have the battery BMS's shut down.

I left the existing charger and all wiring in place and just added the 48 volt charger that came with the kit of 4 batteries. I have read, and seen on Dakota Lithium literature, that the LIFPO batteries are actually 12.8 volt, not 12 volt so, in order to get them fully charged, one would have to use the charger intended for 12.8 volt batteries. I don't know how you would do it using the existing charger and revising wiring but I don't think you'd ever get the batteries charged up all the way to their full potential. All this is covered in my RU-vid video but you'd have to have the patience to watch all the way through my video and I know it is very boring. The kit contained 4 batteries and a 48 volt charger and two 12 volt chargers. There is some discussion of the specs on these chargers in my video.

No, I'm sorry but I haven't determined max range. I use my Polaris EV almost every day and just plug it in to charge every time I put it back into my garage. I think an estimate of 30 miles may be pretty close but maybe a little too high. I have never experienced any diminished performance but, when it was about +11° F in my garage, it wouldn't charge. I'm sure the BMS's in the batteries prevent charging at temps too low for the health of the batteries. Even then. I was able to pull a trailer half full of firewood through about 6 inches of snow. up a steep incline. The Polaris spun a little and tore up the dirt below the snow (aggressive knobby tires). The Polaris can't be driven at full speed in high speed mode....too much current....the BMS's shut it down. I need to experiment with a mechanical means of limiting pedal travel. When the BMS's shut it down, key off and then key on gets it going again.

Hi, DL_Tech. Is that you, Richard? No, I hadn't seen any earlier comments on my RU-vid video. Thanks for the feedback. Glad you liked it. The batteries are working fine after 3-4 months and I use our Polaris Ranger EV almost every day. Merry Christmas to you as well. I did just recently get some DL swag....thanks.

@@tomhaeder1389 hey Tom, this is Shaun i'm on the support team for DL and report to Richard. I hope you liked the gift!

Yes, Shaun, I do like the hoody that was recently sent to me. Thanks. I have recently communicated by email with Josh from your Service Tech Department too. He suggested I experiment with limiting accelerator pedal travel to see if that would solve the shut down problem when operating my Polaris Ranger EV at full speed in the high speed mode. His theory is that the BMS's in the batteries are shutting down the Polaris because current draw exceeds the max allowable for X seconds. I have not found time to try that yet.@@DL_Tech_

Yes, I have just noticed something similar to the momentary shudder. I have been pulling a trailer, loaded with firewood, uphill in the snow. I was in low speed mode and in 4 wheel drive. The Polaris motor would briefly cut out for a part of a second and then get going again. I wonder if the current draw is too great for the BMS limit. It has been very cold where we live. I mean below zero and near zero. I have noticed two other idiosyncrasies. Sometimes, when I'm going downhill and decelerating, the motor will kick out and won't drive. When this happens, I have to put the direction switch into neutral and turn the key off and on again. Then, I can put the direction switch into forward or reverse and the motor will drive again. I wonder if the BMS's in the batteries cannot tolerate the regeneration when I'm coasting downhill. The Polaris EV does charge the batteries while coasting downhill. Also, in the extreme cold, the 48 volt charging system is apparently not working. I plug it in and both the green light (indicating full charge) and the red light (indicating power to the charger) light up. Normally, when charging, the fan in the charger runs. I have not heard the fan lately when it is so cold it does not appear to be charging. I wonder if the batteries or charger cannot tolerate very low temps. It is 31° F in my garage right now and it appears to be refusing to charge. Maybe I need to check for corrosion at the battery terminals.

Now that I think back to before I put lithium batteries into my Polaris EV, it used to exhibit the shudder you mention. My theory is that, then one tromps down on the pedal, the Polaris leaps into motion but then the Polaris system thinks it is going too fast and it triggers the system into the regenerative mode, as though we are coasting down a hill, and then it thinks it is going too slowly so it goes back into the drive mode and the dynamics of the machine make it shudder back and forth for a few cycles. Apparently that shudder has nothing to do with my conversion to lithium batteries.

I believe the shudder is the controller not getting the peak power that it's asking for.