jasonbc said:
if you buy a new battery you still need to charge it from the box, so either way you need a charger. My Varadero went 9 years on the original battery so that can't be bad
I'm not saying don't have a charger. We all need them at some time or other but blindly plugging one in every night only masks other problems. If it was a leaky radiator you wouldn't just keep topping it to max on the bottle up every night. You would find and fix the leak.
Lutin said:
I would have thought that the battery's own self-discharge would be a greater drain than any OEM electronics - be it the bike's clock, speedo/odometer backup, whatever.
I absolutely agree. I would expect any normal drain to be in the very low mA or even uA and self discharge of the battery to be greater. Should still be able to go months without charge though.
Just say the power needed for idle systems is 1 mA (so 1 thousandth of an amp) The battery in my bike is small at 14Ah (or 14,000 mAh if you prefer)
So that would give me a theoretical life of 14,000 hours which is 583 days. Lets assume that a lead acid self discharges at 10% per month so month on month it looks like this
Jan 100%
Feb 90%
Mar 81%
April 72%
May 65%
June 59%
So by the end of June some six months later our battery is still at 60% capacity.
Ahh I hear you shout.. You forgot about all those 1milliamps dribbling out over theses months and you would be right and these would account for the equivalent of about 720mAh each month (so about 4 percent of fully charged capacity month on month) so again after 6 months that's another 24% gone.
So after 6 months we have lost 40% due to the battery self discharging and 24% due to electronics draw so we have about 36% left.
Enough to start the bike? Maybe just, but the figures for three months are 68% capacity left which should be more than enough.