Dry battery

[erod1]

I have been having problems starting my bike lately. I crank and crank and then it starts. Si I decided to open the plugs on my battery. Sure enough they were all dry. I purchased this battery from the BMW dealer on 1/2012.. I filled them with distilled water and charged the battery. Sure enough the bike statrted on the first crank.  Is it normal for all of them to be empty ?

[Bob_Roller]

With a serviceable type battery on a motorcycle, you need to check the fluid level regularly, like once a month .

Also, you need to use distilled water, not tap water, it will also bring a battery to an earlier demise .

Not a lot of fluid in a motorcycle battery, so it goes down fairly quickly, as compared to a four wheeler battery .

During the charging and discharging process, water is broken down into oxygen and hydrogen, that's why the fluid level goes down .

Most likely your battery will not last very long after being run dry, so don't be too surprised if it dies fairly soon .

Next time you get a battery, try one of these, less costly than a BMW battery and in most cases will probably last at least as long .

http://www.staabbattery.com/product/UB12220-V.html

http://www.gruberpower.com/12-volt-18-amp-hour-ah-battery

Both of these batteries are sealed AGM type, never add any water to them .

If your bike sits not ridden for any length of time, or you put it away for winter, a battery tender, not a trickle charger, will help you get a longer life out of the battery .

If you live in a cold weather area, leave the battery where it will stay cold, as long as the battery is charged, the cold will help the battery 'live' longer, the cold slows down the chemical activity inside the battery .

Can't tell where you reside, may want to put that somewhere in your profile .

[erod1]

Thanks for your imput. I have never had to add fluid to the batteries on any of my other bikes. I guess that is why I was surprised. I wonder if BMW will make good on it.

[Bob_Roller]

Only way to know, is to try it .

Here in the Phoenix area, the local BMW dealer will not warranty serviceable type batteries .

You take it out the door, it's yours .

Last time I bought one from them, was in 1997, been using AGM types since .

Batteries live a tough life in the high temps we have here for about 6 months of the year .

I was barely getting 18 months on a BMW battery, they were about $100US then .

Pretty much had to go to them for the smaller battery that's used in the R65's, all the other replacement batteries, required you to cut the battery box and rear fender to get them to fit .

[wilcom]

I would make sure your voltage regulator hasn't gone crazy and "boiling" the battery

[Barry]

As has already been said it should have needed topping up long before now.  I do mine every 3 months and it really needs it.

The battery is not necessarily on it's last legs but the section of plate that was allowed to run dry may be sulphated. In practice the acid splashing around in use may have helped if the electrolyte level was not too low.

One point to add. A brand new battery should be filled, allowed to settle say overnight and then topped up again as the plates will absorb some of the acid and the level will fall below the full mark. Then when it is subsequently topped up to the full mark with distilled water it will have weak acid and it will never reach full charge. It's important to know what level to top the battery up to and if it was not filled right in the first place then you will never know.

Having said all that I don't believe I ever bought a wet cell battery that was properly filled before sale. They just don't have the time (or the inclination) to do it right.

Wet cell batteries are a bit of a pain but with care they can last a long time. I have a Varta wet cell battery that was not new when I got it with the bike so it must be in excess of 6 years old, probably at least 7 or 8 years old.  It has F2 scribed on the top which is typically what the selling dealer does to date the battery for warranty. It may well mean Feb 2002. I wouldn't be surprised as I once got 12 years out of a car battery. I've got to admit it's on it's last legs now and though it has never run flat or failed to start the bike the self discharge rate is getting quite high which is a sign that it needs replacing soon.