vr,
Funny you should ask. I was out of touch all last week. Then yesterday I had a note all all ready to submit when my connection went flaky, and it didn't get posted. I will try again.

OhiOH, your system looks really good! One concern I had about using AAs is charging. I have plenty of NiMH batteries and a couple of chargers, but the prospect of trying to get 12 or 24 batteries charged every night had me scratching my head. I decided to go with SLA primarily to simplify the initial system design and charging issue. I hadn't thought of a flashing headlight though one thing I want to do is set up a REALLY bright flashing LED taillight. I have the light, but I have to work out mounting.

We are using the same Optronics lights. I note your ventilation slits are open. I fashioned a hood from black electrical tape that keeps water from falling right into the vents but still allows for ventilation. I was concerned about water building up inside faster than it could seep out the rather close fitting seam. Since the tape is black it is not noticable at all. I tend to be paranoid about 1) water and 2) physical stability of components (no bouncing or rattling allowed).

I haven't done anything new on my system in the last couple of weeks. I did open my semi-sealed battery box for the first time to check for moisture after 2-3 weeks including several rainy rides. Nice and dry so I feel pretty good about it. And the battery hadn't shifted a bit. It is basically held in place by the pressure and friction of layers of mousepad clamped in place by the top of the box. I do have a rectangle of industrial strength Velcro attaching it to a side wall, but it is probably not really doing much. Still, I feel better with a little insurance.