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Temps

HansLab

Well Known Member
All,
I plan to purchase a light yet strong battery (https://www.super-b.com/en/product/14//sb12v20p-sc), however it's maximum temp is 55 degrees Celsius. It passed my mind that the real temps under our hood are much higher.
Anyone an idea about the actual temps? I might consider a scoop there for cooling this battery, but if not necessary I rather wouldn't.
 
Temps from RV9A

I strongly urge you to review all of the posts from and about EarthX on this forum. Having said that, the temps from my RV9A have topped out at 71 C and I live in Arizona. The temperature strips are directly on the EarthX battery:

F3ET12ZbhTfLKQL9EU9QIViHhGqqd9B0mVKj4-iisyVV7pSMv-1ujqANVvSRbXAPyxv9BOvjz_uzQJ13_AccaRc0LjBUrMPgICFa-HXAlAMDMMTgjyTT7bP0xRohLVhxzLomkhPGGKVo-x98LsbBYr4Eo5L6uIkg_muz8O40KO8UDXNisE4OX5_eIW6St5FklkfRxom7cVq8A6c34A46SRVnj5HpaHw5t8xQkpdTXoCi_CSyUdeu3GR3Z2roSJIDzTV8cg4AhdTp99F-dic9u9onfVeE5tHTgZiWkLgiYzjyvMwlEYy_kGQsowZp1tj2o8LBIJNPtgrlcNnyL0VDis-o0YbSVZQn5G9dm-hLvzjwYgNvwFlvJ5OSipXckmtCaJBysbNyLFgisMa-_sQp5ofHvm67K-yTsulQOXpNVu9_UI0xCMPvqCyNLflvPO4qUk33xel5irnRn_5o_sVhSsWdtCSYMakhg5SqQoPFOKZWboRNp6090bZ_T3azJ1Qk7yHI4x9hdM2b4gPiDg-NZfd0PPstzwd7KGyAOhicK4uayax_8ytyRBh50QCFrJnYRvb1MIsqYTaltpP_7UeUNpEtdidueksQzXQf82uh_Jv45AWgcHHjlDWpbpxeJHZcdAtOeB1tDLC1HrgcLy46i8gP6JqHKn0=w683-h910-no
 
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A maximum high temperature of 63 degrees C was measured by a thermocouple attached to a mounting bolt of the voltage regulator which is located on the firewall shelf inside of the engine compartment. The voltage regulator is cooled by a blast tube which does not blow onto the mounting bolt or thermocouple.
Below is a table showing voltage regulator temperatures in Fahrenheit.
Perhaps the most meaningful temperatures are after engine shutdown with no cooling air and no electrical heating.
_
rpm._t-couple._oat
2690 _ 128.___81
5374 _ 146 _ _ 78
5026 _ 135 _ _ 77
0 _ _ _ 143 _ _ 82
5035 _ 136 _ _ 75
5337 _ 127 _ _ 80
5275 _ 130 _ _ 80
5559 _ 136 _ _ 71
0 _ _ _ 140 _ _ 78
 
Before flying season started this year I placed two temperature recording strips under the cowling of my RV-12 - one on John Deere Voltage Regulator and one on top of ignition unit. Hasn't been hot yet (northern Ohio) and only four flights...



 
All,
I plan to purchase a light yet strong battery (https://www.super-b.com/en/product/14//sb12v20p-sc), however it's maximum temp is 55 degrees Celsius. It passed my mind that the real temps under our hood are much higher.
Anyone an idea about the actual temps? I might consider a scoop there for cooling this battery, but if not necessary I rather wouldn't.

Nobody has mentioned it in this thread yet, but I guess I should mention that the RV-12iS now comes with the EarthX. However, there is a lot more air passing though the cowl on the iS due to the louvers on the top of the cowl.
 
temps

I believe the temps under the cowling will get way past 55 degrees especially after shut down when a cooling vent wont help
also is a lithium battery suited to the rotax style of battery charging
 
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