If it's only a couple of months and you're not leaving the battery outside in freezing temps then I wouldn't bother 'keeping it on a charger'.
I'd remove it, charge it and put it on the shelf - remembering of course to cover the terminals to stop accidental shorts. Then, in a couple of months when I need to reinstall it, I'd check the state of charge and put it back in the bike. Honestly, after such a short time a good battery is unlikely to need a second charge to go back into service.
Of course, opinions on that process vary....
The fuel, ignition and ABS ECUs aren't intelligent enough to realise you have removed the battery - in essence, it's exactly the same as when you turn the key to the 'off' position as far as they are concerned.