Battery, or charging?
 

I had a problem the other day, I reckon it is a charging or battery issue

Bike seemed to be running really rough until I got the revs up above 2500.
Thing is, I was working nights for a few days, so was riding to/from work at night. It is a 15km ride, with 19 traffic lights on the way and speed limit is a mix of 60km/hr and 40km/hr. Clearly puts more stress on the electrical system than at higher speeds

When I got to work I revved it to 3000 for a minute with lights off just to put a spot of charge in. When leaving ten hours later, it struggled slightly to crank, but did start, so I rode most of the way home on parking lights (scary even with almost zero traffic).

I put battery on charge for 12 hours and it settled at 12.6V afterwards, holding charge comfortably for over 24hrs. Disconnecting coils and cranking for 10 secs, it dropped to 10.3V. Doesn't seem unreasonable

Riding since, it seems to be charging OK at 14.3V (headlight off) and 14.6V (headlight on), once it gets above 2200rpm.
At idle battery shows over 13V (headlight off) or 12.4-12.5V (headlight on).


So (finally) the question:

Is my charging system behaving normally?

If so, I reckon the battery is just getting old and will soon need replacement.

Anything else I should be checking?

Other than that, the old beast is running great, but I will likely be selling in the near future to make space for a new project.

That's a recipe for a flat battery right there.

Under those circumstances, I'd put the battery on charge every day.

Fair point, especially given that storing a partially charged battery is not good for it. I am only allowed to ride it 45 days a year as the bike is on a club permit, so it often sits in the garage for weeks on end.

In my defence, I just didn't even think of it until a situation when the battery was clearly flat.

You battery should read 12.8v or above when not on the charger to be 100% charged. I would say you have just about killed your battery by not getting to 100% charge often enough. Leaving a battery at under 100% charge is asking for battery problems, get a good maintenance charger.

Yeah maybe, although I don't ride it much at night, given the club permit scheme limits number of days riding. Most of my riding is 100km+ daytime riding on country roads. It can sit for 2-4 weeks between rides though.

Could also be the previous owner that had it a couple years and never rode it, or even the owner before that - no history on the battery before I got it.

Yup, got a decent charger.

How old is the battery? If its not a newer sealed type it could be low in fluid and would need replacing.

recommend you replace battery with a motobat one!
thats what ive got.

Not sure of battery age. I have had the bike over 2 1/2 years. The previous owner had it in his shed unused for a couple years and he told me about various things he had done, didn't mention the battery. Based on that I suspect it is at least. 4 1/2 years old, maybe much older. It is a Motobatt AGM model.

I went to ride the bike yesterday, first time in nearly two weeks and it wouldn't start - was at 12.4V and couldn't crank. I had charged it after last ride.
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As nobody has suggested the charging voltages are unusual, I am assuming the battery is past it's best.

Will try to rehabilitate it and report back.

From what I have read, your Absorbent Glass Mat (AGM) battery has a lifespan of 3-5 years or up to 6 with good maintenance. If the bike was stored and the battery dropped to 80% or less at any time, its life expectancy would drop.

If the R/R hasn't been upgraded, I'd replace it also. The voltages you reported aren't bad but you could get them with a R/R that's on its way out. Charge the battery and disconnect one lead from the bike. Let it sit over night and check the voltage with the lead still connected in the morning. Then reconnect the lead and have it sit overnight. If the voltage is less with the battery connected in the bike, the diodes in the R/R are getting weak and will eventually fail.

You didn't say what year the bike is in this thread so can't suggest a R/R at this time.

It is a 1990 CBR1000FL, Aus model

The battery IS stuffed - full charge and dropped to less than 10V in under a minute with headlight on.

I went to the market today and purchased some magic crystals. Hopefully they will solve all my problems. More to follow in a few days...