Hi Guys
I've got a Trance 0 and the wife has a Trance 3. Both have had similar battery problems to yours Stu. It was fortunate that we had the same basic bike because that meant I could easily swap things around; batteries and chargers wise.
I bought my bike from the local bike shop, but they couldn't get one in Small for the wife so I had to buy that elsewhere.
The wife's battery fault was blamed on the charger, because it was claimed "Giant have never had a battery fault but they've had lots of faulty chargers" for about two months back and to the LBS (though I never believed it to be the charger because it didn't follow with what was going on). After insisting that it couldn't be the charger I borrowed one from the shop, and her bike still did the same thing, turning off immediately after turning on, the the LBS conceded and put in a claim for a battery, which still hasn't arrived after maybe six weeks now of her not being able to ride it.
My bike has been more reliable than hers, but when it has done this thing of turning off immediately after turning on, it has been doing so after doing a relatively short ride from the battery being fully charged (typically then, but not always, showing four battery lights on the remote).
So Charge up, ride 2-10 miles, turn off, then the next ride it won't turn on again, despite showing plenty, though not full, battery level. Sometimes I charge it up again and it works ok, but I shouldn't keep part charging the battery like that because it isn't good for them.
I feel awkward keep going to the shop because they have been as helpful as they can be with the wife's bike battery problems, despite the fact that I didn't buy the wife's bike from them.
I'm just wondering if you got your fault sorted by Giant ok? With the wife's new battery still not having arrived I still don't know if Giant have fixed whatever the problem is that they have got with them or not.