Hi guys, on the subject of battery holders i think i have finally fine tuned mine to give no problems. Firstly i made an aluminium box to hold it securley in place instead of the poxy tie wrap (TTR EB4). also found that on hard impacts the batteries could slide away from + contact and not spring back so i have wedged a small piece of fuel pipe between the battery holder springs to increase the tension, sorted. Most important thing though is a fail safe and i also fit a exhaust header spring to the throttle arm so even if you loose all electrics it still shuts the throttle, this flattens the batteries a bit quicker and slightly slows throttle response but i don't race and i have had one too many out of control full throttle moments so i reckon its worth the small sacrifices. Just my 2 bobs worth. Hope they help