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An update for Feb 19, 2019

The power probe III tool that I am using has shown me a few things that I should have realized:

- The voltage on the battery terminals fluctuates .. .since this is a PWM controller. That is sort of the DEFINITION of PWM ... it turns on, then it turns off ... REALLY fast ... With the key switched on, no DC converter, and the familiar whine of the controller while the polaris is not moving ... the voltage on the battery terminals does indeed go over 63V ... but that is perhaps switching transients? Using the Fluke and my Step-son's Greenlee meter ... they just don't agree! In any case, the capture function on the Power Probe shows that the voltage reading on my Fluke voltmeter was perhaps a bit weird, but not entirely wrong. And the Greenlee meter reads over 55.2V as well. Turning off the polaris makes the voltage stable and easy to measure, and all 3 meters are within .1V of each other.

- Alligator clips don't work when it is too cold. The plastic freezes and you either can't get the jaws to open or they open and there is no pressure to hold the jaws on the terminal. I had to warm up the gator, pull the insulated cover back, and use the metal/spring clip only. Some days it seems like your equipment is against you!

- The PWM on the controller drops the voltage .. a lot more than I thought. At -28C this morning I tested the polaris in forward, low setting, and full acceleration gave me pitiful power. Acceleration was 8 - 10 seconds, and the top speed was slower than walking pace. The voltage on the Power Probe went as low as 25.5V. Again, I think that this is a transient value and not averaged out.

- I still need to work on installing anderson connectors on the stationary pack. I have #2 AWG battery cables between the pouch cell battery packs and the master switch, as well as from the master switch to the contactor and on the negative side to the controller post. So the new pigtail with the anderson connector must go from a common + point and a common - point on the pack to the master switch on the + and the controller on the -. AND that will use only #8 cable, since that's what the anderson connectors I bought are sized for. I think it will limit my performance in the future ... but I guess it's OK for testing. To make the anderson connections more useful, I looked for a better (easier) place to put a Negative post (besides - on the controler) and a Positive post (besides one side of the not-easily-accessed master switch), so I don't have to pull out the packs to gain access. I have not located anything safe enough as yet. Ideally, I'd like an insulated post with a bolt-down connector, nice solid mount, away from metal, and easily covered by lexan or another clear cover. Has anyone used the large Stereo distribution blocks for this type of thing?
 

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Cold WX OPNS

In my Ranger VLi when operating in temperatures below 50 F (10 C) I apply power carefully and avoid high amperage draws. The Lithium as well as PbA packs are chemical reactions and are sensitive to temperature. I think it is important to remember that there can be Technically Identifiable issues that do not really translate into Practically Experienced problems. Is the service cycle life of the pack reduced by using it in temperatures below 50F? Technically yes. By how much? Practically, I expect that I will not detect it.

"When starting off in the cold conditions, use the vehicle at as low a load / performance as possible give the pack some time to warm through having power flowing through it. Threat the pack gently, long life is somewhat dependant on you treating it kindly." Grumpyb-------------Totally agree.... JackA
Hey Jack - can you explain what you mean by "temperatures below 50 F (10 C) I apply power carefully and avoid high amperage draws"? I just ordered a 210Ah pack from Voltronix and just waiting on it to be produced and word to ship the controller/charger to them. My ATV is a 2016 Ranger EV and after 4 years with (very well watered/cared for) LA I am still getting ~20 miles in very steep WV terrain (mostly gravel roads). I use it all year round, under 32F and I'd say half of the year under 50F. The ATV charges and sits outside with no possibility for a heated garage. Do you think I'd have to get some sort of battery heater pad and which would work? Or is it more an issue of charging after use when the pack has warmed up? I want to make sure I can continue to use my ATV the way I have been the last 4 years after the VLi upgrade. I figure if the Canadian users are satisfied with their Li upgrades I sb good, thanks.
 

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Discussion Starter #24
There is little issue with discharging (driving or using) the pack a low temperature; the degradation is more caused by charging at low temperatures. The Voltronix kit includes an Orion Jr BMS which uses battery pack temperature inputs to control current flow for both discharging and charging. The yellow light on the SOC ribbon display indicates that the BMS is reducing current. The comments you quoted are specific to warming a battery pack up by using it so that the BMS will allow the charging cycle to start. Grumpyb suggested the common sense approach of not drawing high amounts of current when starting out with a "cold" battery pack. It seems to me that this is no different than not using full acceleration on a gas engine that has not reached its operating temperature. Please be sure to post your experience with installing the Voltronix kit and how it performs in your environment.
 

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Charging after use is the best option for charging, but cold usage is a two stage issue. They dont charge well at or about 0c and dont give the power out so well. Both can be mitigated, by charging when warm, and allowing the pack to warm by using at a low rate of discharge. As JackA commented, you shouldnt get into your car and thrash it when its cold. Unfortunately a lot of people do that.
In the UK we have an option of cheaper electricity overnight, and it becomes a choice between better charging and higher power costs or cheaper delayed charging and slightly less range. Its not such an issue with relatively few freezing days here.
Wind around the vehicle is also an issue and that can chill it even further so even if its outside, keep it out of the wind, and perhaps use a cover.
The worst thing to do is just to ignore the issue of cold temperatures and use the vehicle and expect it to perform as it would in warm weather. As commented, Lead also doesnt perform well in cold either,, so dont expect more than reasonable.
 
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