A trickle charger will not charge a dead battery.
A trickle charger's use is to keep a charged battery in a charged condition when not in use.
Test your battery's state of charge with a hydrometer.
The tester is available at auto parts stores for about $5
Yes the battery can be bad.
You need to test the battery charge with a voltmeter or a specific gravity float meter. .. since most motorcycle batteries are closed .. you may not have SG float option.
When you placed the battery back into the motorcycle did you check to see if the horn sounded? .. Lights came on, turn signal worked, did you check for battery terminal corrosion?
Well what does it do? Could it be an electrical problem not associated with the battery charge? Or a mechanical problem?
Have you got a multimeter?
Could be. Take it out and haul it to an Autozone or somewhere like that to get it tested. Could also be your starter, but when you're trying to fix something it's best to start with the stuff that's cheap & easy and work your way up from there.
Most likely yes
Yip. Time to buy a new battery.
You fried the battery!