Bad battery

[shchuka]

Hello all.  I've got another issue that I'm struggling with.  When I first bought the bike about 5 months ago (it's a 97 E model), it had a bad battery that wouldn't hold the charge.  No worries, got a new battery along with the plugs and she ran well again.  The old (bad) battery was Yuasa MF CB10L-B2.  And so was the new one.  Now, only 5 months later, the new battery is not holding the charge.  I can roll-start the bike (rolling downhill, then drop into second gear) - and she runs well.  Yet, the battery wouldn't hold more than 10V.  I charge it to the max - 13.7V.  Disconnect the charger and connect the digital multimeter.  I can see the voltage go down from 13.7 to 12.2 in about 2 minutes, then down to 11.5 in about another 10 minutes, after 30 minutes it's 10.5 and after a day it's 10.1V.  At this point, the discharging stops.  Interestingly, the old battery discharges to about the same level - but much quicker - down to 10V in under 30 minutes.  Before you ask, yes, I checked the electrolyte level - and it's fine.

I bought another battery - different manufacturer this time - should arrive today - will see how things go with it.  However, I would really want to know what makes the battery go bad.  Is it just my bad luck or something in the bike?  The bike never stands unused for long time.  If it stands for more than a couple of days, I remove the batter and take it inside the house.  As always, any help is greatly appreciated.

[Paulcet]

Might want to check the charging system, just to be sure. Look in the FAQ for the procedure.

[Big Rich]

You didnt mention it so i thought i would ask: are you charging the battery properly once you get it? And using distilled water, not tap water?

[shchuka]

I did test the charging system - and it's fine.  I charge the battery using a standard battery charger from Halfords.  They are not filled with water, but specially purchased electrolyte.  I know the regulator/rectifier is faulty - I have a replacement one that I need to install.  Yet, the regulator/rectifier has been like that for the good part of the last 5 months and the battery only started playing up in the last month or so.

[Paulcet]

Bad R/R can damage your battery.

[JAY W]

Sounds to me like Reg/rec` leaking to earth.Try charging off the bike and testing.

[sledge]

I know the regulator/rectifier is faulty - I have a replacement one that I need to install.

Didnt we do this one a few months ago and havent you answered your own question here?

Replace the reg/rect now.

From a statement you made in a previous thread you know its suspect due the effect engine rpm has on the indicator flash-rate  ........The original reg/rect might be appear to be charging but at the same time and depending on the exact nature of its fault it could be intermittanly alowing a higher than acceptable voltage into the system, or allowing current to leak to earth, or it might not be properly rectifing the AC output from the generator and allowing "Lumpy DC" into the system. All of which are not good for the long term health of a battery and could explain why yours has failed in a relatively short period

If you dont replace the reg/rect whats the betting you will be back in a few months asking the same question and wondering why your new battery has also only lasted a few months  

[shchuka]

Thanks for all the replies.  I replaced the r/r now - but the seller sent me a wrong battery.  The courier is picking it up today.  Hopefully I'll get the replacement before the weeend and will have a chance to ride her again after a month of no-action.

[shchuka]

Yay!  She's running again!  As I mentioned, I replaced the faulty r/r the other day.  Got the new battery yesterday, fitted it in and attempted to start.  She spattered and died.  Choke fully open.  I tried starting again - and added a bit of a throttle this time. She spattered again, misfired - but didn't die.  I release the throttle and let her idle for a bit - the sound evened out and the engine sound was perfect. I suppose, a bit of old petrol in the carbs.  Once that burnt, the fresh petrol from from the tank was ok.  Didn't have time to take her fora ride yesterday, so had to turn her off.

This morning she started with the lightest touch of the button, no spattering, no misfiring - perfect!  I rode from home to work, about 32 miles, just over an hour ride - not a hitch.

I LOVE THIS BIKE!