Battery temperature-soil temperature

Bluedog225

Texas
Joined
Nov 18, 2019
Messages
469
I’ve been reading about the impact of temperature on LiFe batteries. It looks like our “normal” Texas 105F degree summers are not ideal.

After looking around a bit though, it appears that our soil depth at 20 inches is about 73F (23C). Not bad.

Has anyone put their batteries in a vault? I can see some drawbacks (mostly the possibility of flooding and access). But it would seem worth it for the constant favorable temp.

Here is a map of the US with ground temps. This was more difficult to locate than I would have thought.

 

Jim Burrow

Solar Addict
Joined
Jun 27, 2020
Messages
454
Like Texas, here in my part of California (40 miles East of San Francisco), the average temperature hovers around 98 degrees. With respect to my LiFe battery, I have it in the shad as the battery is outside next to the house. Even so, the battery all summer by 1:00 pm was 100 degrees Plus and at times got to 110 degrees.

Since I don't have the option to put my battery in the ground like you were thinking of doing. I was thinking of putting the battery 80% submerged in a 15-gallon container. Making sure of course that the terminals were will be protected from getting wet. With plenty of water in the container and in the shad, the battery should be well below 100 degrees. However, I have never tested the 15-gallon container full of water to see how low the water temperature would be with respect to the surrounding air temperature.

As far as winter goes, it never gets below 40 degrees over the last 3 years. Last winter, I never even seen frost on the roofs of homes.
 

DThames

Photon Sorcerer
Joined
Nov 22, 2019
Messages
1,440
I have started an experiment and never got to the active part of it. I have a 3" pipe about 3' long buried about 30" deep, in a ditch that I had open for a different need. From that pipe, I have a small diameter line coming up to the surface (insulated) and a return line that takes the water back to the other end of the 3" pipe. The idea to test is to use the ground as a heat sink or a heat source. It might not be great but if it can keep a battery box down to 85F in summer or above 35F in the winter, that would be a good thing to know. This topic has came up before.
 

rcrracer

Solar Enthusiast
Joined
Apr 10, 2021
Messages
86
Like Texas, here in my part of California (40 miles East of San Francisco), the average temperature hovers around 98 degrees. With respect to my LiFe battery, I have it in the shad as the battery is outside next to the house. Even so, the battery all summer by 1:00 pm was 100 degrees Plus and at times got to 110 degrees.

Since I don't have the option to put my battery in the ground like you were thinking of doing. I was thinking of putting the battery 80% submerged in a 15-gallon container. Making sure of course that the terminals were will be protected from getting wet. With plenty of water in the container and in the shad, the battery should be well below 100 degrees. However, I have never tested the 15-gallon container full of water to see how low the water temperature would be with respect to the surrounding air temperature.

As far as winter goes, it never gets below 40 degrees over the last 3 years. Last winter, I never even seen frost on the roofs of homes.
Aug. 16th, 2021 the average day temp at the below location was 81.8F. Probably a few stations closer to your conditions, location.
Water volume will be displaced by battery. < 15 gal.
Heat will be transferred from battery into the water. If interested I have a low budget idea for evaporative cooling of water.
 

Jim Burrow

Solar Addict
Joined
Jun 27, 2020
Messages
454
Aug. 16th, 2021 the average day temp at the below location was 81.8F. Probably a few stations closer to your conditions, location.
Water volume will be displaced by battery. < 15 gal.
Heat will be transferred from battery into the water. If interested I have a low budget idea for evaporative cooling of water.
For the San Francisco bay area, 60 degrees to 80 degrees is normal. But I'm 40 miles East of San Francisco in the valley and the temperatures during the summer daytime can be 40 degrees hotter. here in Livermore, the average temperature for the last 50 years that I have lived year has been hovering around 100 degrees and gets up to 112 degrees on some days. Except for the last 3 years where it has been cooler and averaging around 98 degrees. This year we only had 5 days where the temperature got a little over 100 degrees. - Dang, if this is climate change for my area, bring it on!

Anyway, is it would be interesting to see your evaporative cooling of water. If I stay at this home for another summer, I'm going to need to try something else to cool the battery below 100 degrees other than a big fan on it.
 
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