-
Welcome, Guest! We hope you enjoy the excellent technical knowledge, event information and discussions that the BMW MOA forum provides. Some forum content will be hidden from you if you remain logged out. If you want to view all content, please click the 'Log in' button above and enter your BMW MOA username and password. If you are not an MOA member, why not take the time to join the club, so you can enjoy posting on the forum, the BMW Owners News magazine, and all of the discounts and benefits the BMW MOA offers?
-
Beginning April 1st, and running through April 30th, there is a new 2024 BMW MOA Election discussion area within The Club section of the forum. Within this forum area is also a sticky post that provides the ground rules for participating in the Election forum area. Also, the candidates statements are provided. Please read before joining the conversation, because the rules are very specific to maintain civility.
The Election forum is here: Election Forum
Dead Battery
- Thread starter noitca09
- Start date
sailorlite
New member
What is the age of the battery? If it's the original BMW battery you should consider replacing it before you go any further. But if it's a "new" battery you should double check that the connections are clean and tight.
I don’t understand what seems to be “shorthand”?
Is the battery original and going dead and you would like to put a new battery in but concerned it will go dead like the original?
A properly installed “good” battery will sit a long time without going dead.
OM
rangemaster
New member
Left unattended any battery can go flat...but there are reasons.
One of the common ones I see on BMW bikes is improperly installed accessories - like a USB socket wired directly to the battery.
One rider I knew had done just such a thing, not controlling it by a relay or (ignition) switched accessory circuit. Even though he had no USB accessory plugged into the socket, it still consumes power as it must convert the 12V on the bike down to 5 V.
If the bike sits and is not on a battery maintainer of some type this USB socket will eventually flatten the battery to the point where you can’t start the bike.
Another one might be the BMW DWA (the alarm system).
Also keeping certain memories alive (like radio station presets and clock time) can cause minute current drains that stack up over time.
As others may have suggested, when the bike is sitting in the garage (not running) attach a DC ammeter in series with the battery, or just use a clamp-on DC ammeter if you have one; this will tell you how much current is trying to be drawn by the motorcycle electrical system when the key is off.
Watch the ammeter for several minutes as your onboard systems managed by the bike take about 30-60 seconds to shut down.
Let’s say after 5 minutes you still show a .2A (200 mA) continuous drain; that means for every 24-hour period the bike is sitting you’re using 4.8AH (Amp-Hours).
Hint: most of our motorcycle batteries are maybe 12-19AH capacity at best.
At this rate it doesn’t have to sit very many days not being started and/or ridden (or not on a battery maintainer) before you have a flat battery.
Hope this explanation helps.
Ride safe!
Gregg
Sent from my iPhone using Tapatalk
One of the common ones I see on BMW bikes is improperly installed accessories - like a USB socket wired directly to the battery.
One rider I knew had done just such a thing, not controlling it by a relay or (ignition) switched accessory circuit. Even though he had no USB accessory plugged into the socket, it still consumes power as it must convert the 12V on the bike down to 5 V.
If the bike sits and is not on a battery maintainer of some type this USB socket will eventually flatten the battery to the point where you can’t start the bike.
Another one might be the BMW DWA (the alarm system).
Also keeping certain memories alive (like radio station presets and clock time) can cause minute current drains that stack up over time.
As others may have suggested, when the bike is sitting in the garage (not running) attach a DC ammeter in series with the battery, or just use a clamp-on DC ammeter if you have one; this will tell you how much current is trying to be drawn by the motorcycle electrical system when the key is off.
Watch the ammeter for several minutes as your onboard systems managed by the bike take about 30-60 seconds to shut down.
Let’s say after 5 minutes you still show a .2A (200 mA) continuous drain; that means for every 24-hour period the bike is sitting you’re using 4.8AH (Amp-Hours).
Hint: most of our motorcycle batteries are maybe 12-19AH capacity at best.
At this rate it doesn’t have to sit very many days not being started and/or ridden (or not on a battery maintainer) before you have a flat battery.
Hope this explanation helps.
Ride safe!
Gregg
Sent from my iPhone using Tapatalk
lee
Debbie's Servant
I take it you did not have the problem with the original battery?
When you installed the new battery did you also install a new accessory that draw power like Gregg mentioned?
How long does it take to draw the battery down? A couple days, you have a problem. Four weeks? Normal. Newer, electronically controlled motorcycles draw a bit of power when shut off.
If the motorcycle does not get ridden at least once a week, and then for at least a couple hours, buy a battery maintainer and plug in the maintainer when it is parked, all the time. Battery Tender is one brand, there are others.
If the motorcycle does not get ridden at least once a week, and then for at least a couple hours, buy a battery maintainer and plug in the maintainer when it is parked, all the time. Battery Tender is one brand, there are others.
