Strictly Speaking I suppose this isn't a question for lights as it is pertaining to the effects of the weight of the battery on handling (as opposed to the light produced) but I didn't know where else to post it!! I am looking at various Li-Po or NiMH between 250g and 600g.........1)In top-tube/downtube corner.............2)In downtube bottle mount...............3)Under saddle. (my favourite idea).................4)Anywhere else.....................What would be best so as not to effect the handling of the bike whilst riding red/black grade trails? Or does it really not matter much at the weights I am talking about? The silly dots are there becasue I can't for some reason do paragraphs now?!?!Whats up with formatting?Marco.
When seated, you are tightly coupled to the bike and you outweigh immensely the battery. Out of the saddle, when the bike moves with respect to your body, it may matter somewhat, but still not too much. Placement at the center of mass is ideal, of course. You have three dimensions to play with. Left/right direction is for free, just center it in that dimension. Fore/aft direction placement will primarily affect what happens when the bike tilts fore/aft beneath your body. Vertical placement will affect both fore/aft tilts and left/right tilts (from out of the saddle pedaling).
If you care a lot, perhaps you can just experiment. If I had nothing else occupying the space, protection from mud (fenders, saddlebag, etc), and a convenient mounting method, I would probably choose the saddle mount you mentioned. Personally, I can feel my battery pack (when I use heavy battery-powered light), but it's not very signficant for me, even off road.
