I wouldn't leave a charger plugged in all the time not sure if it does batt any good ? so I put mine on once a week or so when in garage it's all ok trickles it for a while then all green saying fully charged
The normal lead sulphate in battery cells is soluble. Normal in-use charging and discharging moves sulphate ions between the electrolyte liquid and solid plates.
Lead acids will also self discharge but this sulphate is non soluble. Gradually it builds up and clogs the battery to death.
Charging every month is better than nothing but for 30 days (out of 31), the self discharge is growing hard sulphate.
Optimate avoids overcharging by allowing the battery to drop its voltage a little then topping it up again. The voltage drop isn't enough to allow hard sulphate to develop.
Plus I run engine once every week or two 5 mins to keep fuel flowing though.
Every gallon of petrol burns to a gallon of water plus CO2. Run an engine for five minutes and the water generated will condense into the exhaust system along with a fair amount of acidic products of combustion. The remaining water will have blown past the piston rings and settled into the engine oils. Shut off After 5 or 10 minutes and the engine it still too cold to have evaporated that water.
We all know that most engine wear happens on a cold starts - no oil until the pump is turning so bearings run dry for a few turns. Simply starting it for a few minutes each week = 100% wear with 0% use.
Tickover speed is toxic especially to cold engines. The moving parts are not spinning fast enough to smooth out the competing loads causing excessive wear. Many bikes run fast on cold start tickover.
Really big engines have jacking oil pumps to feed the bearings for starting.
Don't leave the bike on tickover while getting dressed. Start the engine and ride away.
Avoid short runs where it never gets properly warmed up.
Don't leave it ticking over for long periods even when warm.