Sun/Heat Shield for Battery

Darrin Roush

New Member
Has anyone fabricated a sun/heat shield for their battery when riding in direct sunlight in hot weather? I've read about the heat damage to batteries and significantly shortened battery life when folks have ridden in very hot environments (e.g. Arizona/Texas). Obviously ambient temperature cannot be mitigated if one chooses to ride in it, but powerful rays of the sun striking the battery would certainly take it up a notch, wouldn't it, especially if batteries of dark colors are mounted to the frame in an open an exposed area? (My battery is mounted to the downtube where the water bottle usually goes.)

In light of the replacement cost for these batteries being in the several hundred dollar range (if not more), I've got the idea in mind to fabricate a sun/heat shield for the battery to keep direct sunlight off the battery while riding in hot weather and still allowing airflow over the battery itself. The idea is to deflect heat from direct sunlight off of the battery while allowing heat from the battery itself to still be dissipated by airflow over the battery. This might be perceived as overkill by some, but again, in light of lithium ion battery health being sensitive to heat and the replacement cost, wouldn't this seem like a good idea?

I've procured a piece of aluminum sheet metal that is very thin, light and shiny that should do the task of deflecting sunlight heat from the battery while adding virtually no weight. If shaped to fit over the battery so that there is a gap (with perhaps small rubber foam pieces in between to hold and cushion it), airflow can be maintained over the battery (while riding).

What are others' thoughts on this? Constructive feedback is much appreciated.

arnold ziffle

New Member
I like where you're going --- DIY engineering for cost effective improvement. I don't know you're aesthetic requirements, but louvers are a cool, retro, & functional ---- but you'd need fab shop to stamp them into your sheetmetal. Consider lightning holes, maybe in a pattern? Also, a finned aluminum inline/V engine valve cover is about the right shape to cover a downtube battery?


New Member
isnt there a reflective contact paper/window tint? mirror finish will reflect back most of the rays while the thinness of it will allow for heat transfer.


Well-Known Member
High ambient temperatures reduce battery life.. There is no evidence, nor does it really pass the sniff test, that riding your bike out in the sun for a couple of hours a day will reduce battery life. Now, if you were leaving your bicycle out all day every day in direct sunlight, then that would increase battery temp significantly; just cover it or park in the shade.

If you really want to make a difference in the battery life of your bike, store the battery with or without the bike inside a temperature controlled place when youre not using it.

Even more important than temp is not using the full capacity of your battery.. Charge it to only 90%, and charge it before it gets below 20%. Supposedly that will increase the life of your battery significantly.. Check out Battery university.