You can always have a quick connect charge kit, which is a cable that's permanently hooked up to the battery on your quad. You can then route the waterproof cable to an easy to reach location on your bike ( by your bar clamp or under the seat, etc) this then connects to the charging unit. They sell them on eBay
Or if your bike gets a bit of light fit a solar powered trickle charger to the bike they're very small, cheap and you let the sun keep your battery charged for you.
Just another couple of options.