Cold battery workaround

Yesterday I re-experienced a prob i have with the trike in winter - motor chugging, mainly up big hills. I think it's the cold. My fingers were freezing (after taking them out of mitts to take pics) going in the direction of the chugging. When turned and had the wind at my back, fingers thawed and no more chugging.

I have this bike trunk for the Hilltopper battery in summer, just to give it a place to live. The seat post strap is really worn down due to some rubbing i didnt realize was going on. So the batt lives in this trunk on the rat trap. But it almost overheats in spring-summer in there. Half way thru a short ride, I have realized it's noticeably to the touch. So i unzip and let the heat out. (I likely need another solution with better airflow for the HT batt.) But it occurred to me yesterday, maybe that heat buildup could be useful for winter riding.

Shown here is my Solo Rock battery. It's a tight squeeze to get it into this trunk. But it does fit. When i checked the battery this morning - temp +1C, no sun - the batt was cool to the touch. Certainly no signs of overheating. No chugging. Next step - try this on my steep, cold hill for effect on chugging.

Re moisture. I had left the front end, closest to the wheels, unzipped. There were a few water drops on the batt on the open end. I can certainly orient it so that it zips around further. Not sure if it will offer protection from salt.

Perhaps the old slush-proofing go-to, Scotchgard around the trunk. After that, an aesthetic plastic bag for the winter.

So far so good.