I used a trickle charger on my last bike to top up occasionally, but that had an alarm.
Since I have had this bike, no alarm, I have never put it on charge. I checked recently after it had not moved for a month but the trickle charger still wasnt needed.
Over winter I never even had it on charge (have an alarm) then thought I'd better charge it ready for none icy roads weather. I charged it once over night and started using the bike. Since then I've started using the bike everyday so I don't bother charging it.
Fwiw I have a couple of Optimates, and use them all the time. On the bikes I don't use I have the batteries daisy-chained on an Optimate to maintain them & avoid them becoming sulphated.
They seem to last very well, no side effects & no failures.
What type of trickle charger are you using mate,.?
I never put the battery on trickle charge, just disconnect it and take it off when the bike goes away in winter - then when it's ready to go back on the road I just charge before putting it back on the bike.
Optimate here, interestingly I bought a battery from a company on Ebay a few years back and they enclosed a sheet of paper regarding use of trickle chargers. Essentially they claimed that modern trickle chargers of the Optimate style "wore" a battery out with the constant charge/discharge, and consequently anyone using one of these chargers on a battery supplied by them would invalidate the battery warranty, how they expected to find out I don't know, and I'm fairly sure trading standards may not agree with statements like that, however I only mention it as I'd never heard of this before or since. Anyone else?