Dropping Temperature / Performance decline

[MiltonC]

Originally Posted by yurtle

I've never seen an RXV. Now I know why you said it looked like a fuel gauge.

I think that it is the exact same gauge for a Gas Cart. I ordered a wiring harness to convert for electric. It only uses 3 of the 5 wires on the gauge.

[JohnnieB]

Originally Posted by MiltonC

Thinks for the education Kernal,

I get about the same distance from my cart during warm weather as you. I will just continue to charge the batteries after everytrip which is usually in the 2-8 mile range.

Based on a battery pack voltage check using charts supplied by JohnnieB and others on this forum my SOC meter has been pretty acurate.

If I am understanding, if the SOC meter is working correctly I should see the guage drop roughly 30% faster during cold weather. However, the initial voltage on the battery pack would be the same.

In simpler terms (if I am right), my cart goes from getting 18 mpg to 12 mpg although in both cases I am starting with a full tank. As long as I don't run the tank to less than 1/2 full, I am ok.

The 18mpg to 12mpg is a good analogy.
(Technically, the size of the gas tank shrinks from 20 gal down to ~15 gal as well as the mpg dropping from 18 to 12.)

Sounds like you've got a pretty good handle on what happens when the temperature drops.

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I believe you are right about the same gauge being used as a fuel gauge in a gas powered RXV.
As such, it is probably dampened so the needle doesn't bounce around wildly as the fuel sloshes in the tank, which also means it doesn't respond quickly the variations in battery pack voltages, so it probably doesn't drop much during acceleration and climbing steep hills like a undampened meter does.

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Charging after each trip is the best thing to do, regardless of temperature.

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In your post#4 you listed some options and had a question.

Options are:
1. Quit driving in cold weather No need to quit, shorten maybe, just keep SoC above 50%
2. Store the cart a heated garage If possible and practical.
3. Place a heating device under the battery pack (heat lamp etc) while outside. No, probably not a good idea. Might be okay if you can monitor and regulate the temperature, NO otherwise.

At what point is the temperature too high for a battery pack? I've seen 120°F as the max temp while charging, but I wouldn't artificially heat a battery anywhere near that.
In fact, I wouldn't artificially heat batteries with anything other than heaters specifically designed to keep batteries warmer than ambient in sub-zero weather.


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Here is the battery life expectancy vs average SoC chart Kernal spoke of.

[MiltonC]

Thanks Guys, I've got a lot better understanding. I didn't realize that the "gas tank" got smaller also. I just like to be knowledgeable so I can try to get maximum service from my batteries.

Thanks for the discussion.

[MiltonC]

"At what point is the temperature too high for a battery pack? I've seen 120°F as the max temp while charging, but I wouldn't artificially heat a battery anywhere near that.
In fact, I wouldn't artificially heat batteries with anything other than heaters specifically designed to keep batteries warmer than ambient in sub-zero weather."

Johnnie,

Just for the record, I wasn't thinking of heating the batteries, but live in a climate that can hit an air temperature of 103 deg F in the summer. I was thinking I might need to keep it in the garage in the summer to avoid the heat also. Especially when charging in the summer I've smelled a lot of gas. But then I will need to have some ventilation.

[JohnnieB]

Originally Posted by MiltonC

"At what point is the temperature too high for a battery pack? I've seen 120°F as the max temp while charging, but I wouldn't artificially heat a battery anywhere near that.
In fact, I wouldn't artificially heat batteries with anything other than heaters specifically designed to keep batteries warmer than ambient in sub-zero weather."

Johnnie,

Just for the record, I wasn't thinking of heating the batteries, but live in a climate that can hit an air temperature of 103 deg F in the summer. I was thinking I might need to keep it in the garage in the summer to avoid the heat also. Especially when charging in the summer I've smelled a lot of gas. But then I will need to have some ventilation.

You never know who is going to read what is written on the form, so I was just being cautious.

The graph attached to Kernal's post#2 shows the battery capacity increases by about 10% for every 20° above 80°F as well as decreasing below it and the text explains that the battery life-span is reduced.

I'd park it in the shade for sure, but other than that, just lift the seat let it air out a few minutes before working under the seat.