I think a new battery would be far less money and hassle. Zero running cost too.

That depends what bike you have. The official battery for my bike is 10,000B. A good charger is much more economical.

Yes there is a difference to charging the wet type battery and the gel type. The big old car battery charger you buy from most hardware stores, unless it specifically says for gel/sealed batteries, will probably wreck your sealed/gel battery. These chargers are very basic internally with a rough DC output. The front panel current meter is likely to be an old moving iron type which are very slow to react and will only show the a general average. This will not show anywhere near the current peaks caused by the rough output so it will probably be charging the battery at a higher rate than you think it is. This higher rate can cause the battery to 'gas off'. In a wet battery this is not a problem, you have filler caps and they have vents in them to allow the gas to escape, I think everyone has seen a wet battery bubbling away. This gas by the way is Hydrogen so do not try smoking over a charging battery. Your sealed/gel batteries have no such vents except an emergency one which prevents an explosion. The charger mentioned on here, the Ctek and others provide a smooth and generally, a low charging current to prevent gassing. The Ctek is available here in Chiang Mai from at least one motorcycle shop that I know of. Another make is Optimate, I have an older version of this type which has always kept my bikes ready to go after laying idle for 3 months at a time.

well substantiated and welcomed contribution; thanks for sharing!

I think a new battery would be far less money and hassle. Zero running cost too.

That depends what bike you have. The official battery for my bike is 10,000B. A good charger is much more economical.

Let's not forget quite a few bike owners do have a car as well, and subsequently an extra battery to maintain