Keeping Charger always on Bike (plugged in to battery)? bad?

Is it bad to keep the charger permanently tied to the bike.
I have it zip tied to my pack and just pull out the wall plug to charge.

Is it bad to have the charger plugging in to the battery while I ride around?

I use a china battery with aluminum case and their included charger

on my old build the charger light would come on green if it was plugged into the battery but not the wall
this new one (with fan) is off if plugged only into the battery

thanks

It won't hurt the battery, but most chargers aren't great at handling lots of vibration and moisture..

Yes most charges will rattle apart on the road. You need to carry in a backpack if you must carry it is best left at home work or office.

If you want a charger designed to be bike mounted, intended to survive riding conditions (and is weatherproof, too), the Cycle Satiator by Grin Tech at http://ebikes.ca is a good (if expensive) choice. It's also designed to be left connected ot the battery, as it has an internal relay to disconnect it when not in use.

A cheaper (but still a bit expensive) option is HLG -A series Meanwell LED PSUs. There's a number of threads about those, if you're interested. These do not all have anything to disconnect them from the battery when not in use, so for those that don't their power LEDs will drain some small amount of current constantly. it's not a lot, but it's there.

I've mounted my charger in my scooter and it's been like that for years: no problem whatsoever.

You only need to make sure that it won't meet water at any point and that it is fairly well cooled. If you're concerned about vibrations you could crack it open and use some epoxy to prevent the capacitors and other stuff from falling apart.

Check the charger doesn't drain the battery when it's unplugged from the mains supply.