battery?

[PastorJay]

I purchased a new battery about 14 months ago but just recently there have been times my bike will not crank enough to start. If i jump it it starts no problem, when I am riding and check the voltage it reads 12-14 and the next day it may not start. What's the problem. Do you think I should just get a new battery? Do you think something else is amiss. 

Thanks again for the help.

Also, Any suggestion on a reliable battery. 

[TEWKS]

I’m going to end up buying a new battery in the very near future by posting this.  I still have the stock battery in my eight year old RT and it starts reliably every single time I hit the starter. The only thing I do is plug it into a battery tender Jr when I’m not riding it. Which is a lot more than i’d like to admit.  My suggestion is go with the stock battery that came with the bike ( don’t recall the brand at the moment) and tend it when not in use.

[Miguel!]

I too have used battery tender (Jr.) for years. I have three of them: one on my 2001  R1100RT, one on my small 1993 Honda tractor, and one on my car that has been sitting for months in my garage. I have never had a dead battery in any of my 3 vehicles. I keep them plugged in all the time unless I'm using them. Miguel

[Hosstage]

I think one thing you may want to do is put a meter on the battery and measure standing voltage, and then running voltage. Measure it at cold (high) idle, warm (low) idle, and at about 2000 rpm. It should run about 14.7 volts at full charge.

It's also possible your battery is failing.

A battery tender of some sort is good practice.

[John Ranalletta]

11 hours ago, PastorJay said:

I purchased a new battery about 14 months ago but just recently there have been times my bike will not crank enough to start. If i jump it it starts no problem, when I am riding and check the voltage it reads 12-14 and the next day it may not start. What's the problem. Do you think I should just get a new battery? Do you think something else is amiss. 

Thanks again for the help.

Also, Any suggestion on a reliable battery. 

 

DR to the courtesy phone.  There's a method for checking from DR.I experienced a parasitic drain and DR diagnosed it.  It was a USB dongle in the tank bag.  It took more than an overnight to discharge though. 

 

Afternoon John 

 

Do a patristic draw check on that motorcycle, don't disconnect the battery without putting your meter across the cable to battery post first  (no power down) between  turning the key off & checking the patristic draw. (you have to be creative on hooking your meter up  BEFORE the battery disconnect)

 

If you find a significant draw then test again with the top box unplugged, GPS disconnected, add-on  fuse box disconnected, anything else that was  added disconnected.

 

More than likely something isn't shutting down at key-off, or your  can-bus circuits are not shutting down. 

 

If you don't find anything by disconnecting the above mentioned things then do another draw test with the voltage regulator disconnected.  

 

[dirtrider]

11 hours ago, PastorJay said:

I purchased a new battery about 14 months ago but just recently there have been times my bike will not crank enough to start. If i jump it it starts no problem, when I am riding and check the voltage it reads 12-14 and the next day it may not start. What's the problem. Do you think I should just get a new battery? Do you think something else is amiss. 

Thanks again for the help.

Also, Any suggestion on a reliable battery. 

Morning PastorJay

 

Lots of reasons but let's start by you telling us what motorcycle make, model, year, & country  that your working on? 

[PastorJay]

1 hour ago, dirtrider said:

Morning PastorJay

 

Lots of reasons but let's start by you telling us what motorcycle make, model, year, & country  that your working on? 

Thanks, 2015 rt,  I live in the state of confusion...NY. I purchased a "MEGA-CRANK" battery from battery mart about 14 months ago. Im thinking of doing what many have said and put in on the trickle charger when not using it. See what happens. The problem is I'm planning on a week long ride this August. then what. 

[TEWKS]

Is it easy enough to bring the battery back and have them load test it? Maybe they will prorate the battery, if it’s weak.

 

Jr. 

 

 

[dirtrider]

32 minutes ago, PastorJay said:

Thanks, 2015 rt,  I live in the state of confusion...NY. I purchased a "MEGA-CRANK" battery from battery mart about 14 months ago. Im thinking of doing what many have said and put in on the trickle charger when not using it. See what happens. The problem is I'm planning on a week long ride this August. then what. 

Afternoon  PastorJay

 

OK, then that also brings a possible internal alternator partial failure into the diagnosis.

 

Do you have a decent  DC voltmeter that can read in the 12-20 volt DC range. If not then we are really guessing on this one.  

 

You need to verify charging voltage at the battery with engine running between 2500-3000 RPM's, at that RPM you need to see over 14.0 volts DC (preferably 14.2-14.4 volts) 

 

If that tests OK then you probably should do a parasitic draw test  (doable at home but not easy if this is your first time).

 

And as TEWKS said, a basic battery load test would also be a good idea.  

 

But you REALLY need to test that alternator output, if that is failing then something like that will REALLY ruin your trip & something that you REALLY don't want want to fail far from home, or far from your dealer of choice.   

 

A total alternator failure should give you a dash warning but sometimes just a partial failure will output enough to prevent a warning but not quite enough to keep the battery charged.

[PastorJay]

On 7/6/2022 at 10:58 AM, dirtrider said:

Afternoon  PastorJay

 

OK, then that also brings a possible internal alternator partial failure into the diagnosis.

 

Do you have a decent  DC voltmeter that can read in the 12-20 volt DC range. If not then we are really guessing on this one.  

 

You need to verify charging voltage at the battery with engine running between 2500-3000 RPM's, at that RPM you need to see over 14.0 volts DC (preferably 14.2-14.4 volts) 

 

If that tests OK then you probably should do a parasitic draw test  (doable at home but not easy if this is your first time).

 

And as TEWKS said, a basic battery load test would also be a good idea.  

 

But you REALLY need to test that alternator output, if that is failing then something like that will REALLY ruin your trip & something that you REALLY don't want want to fail far from home, or far from your dealer of choice.   

 

A total alternator failure should give you a dash warning but sometimes just a partial failure will output enough to prevent a warning but not quite enough to keep the battery charged.

Was able to check charging voltage 14.1-14.2 so that looks good. Will attempt the parasitic draw test. Thank you. In the mean time I have been hooking up the trickle charger when parked. No problems since then. 

[dirtrider]

1 hour ago, PastorJay said:

Was able to check charging voltage 14.1-14.2 so that looks good. Will attempt the parasitic draw test. Thank you. In the mean time I have been hooking up the trickle charger when parked. No problems since then. 

Morning  PastorJay

 

When you run the parasitic draw test be sure to connect a jumper wire between the actual battery post & the battery cable BEFORE disconnecting the battery cable. (do have your meter hooked up before disconnection).

 

Then allow  (or make sure) that the computer controlled accessory circuits have had enough time to shut down (to prevent an active accessory circuit from skewing your parasitic draw measurement).

 

Once all is ready THEN you can disconnect your jumper wire to accurately measure the actual key-off parasitic drain.  

 

I don't have an actual published parasitic drain measurement to give you on your 2015  but based on prior 1200RT's & other similar BMW electronic  motorcycles I would guess somewhere around or under 3.0 mA would be in the ball park. 

 

If your motorcycle has an alarm, that can increase the  parasitic drain so that would have to be figured out depending on the alarm type & if it is set or not at time of measurement. 

 

[PastorJay]

On 7/9/2022 at 8:20 AM, dirtrider said:

Morning  PastorJay

 

When you run the parasitic draw test be sure to connect a jumper wire between the actual battery post & the battery cable BEFORE disconnecting the battery cable. (do have your meter hooked up before disconnection).

 

Then allow  (or make sure) that the computer controlled accessory circuits have had enough time to shut down (to prevent an active accessory circuit from skewing your parasitic draw measurement).

 

Once all is ready THEN you can disconnect your jumper wire to accurately measure the actual key-off parasitic drain.  

 

I don't have an actual published parasitic drain measurement to give you on your 2015  but based on prior 1200RT's & other similar BMW electronic  motorcycles I would guess somewhere around or under 3.0 mA would be in the ball park. 

 

If your motorcycle has an alarm, that can increase the  parasitic drain so that would have to be figured out depending on the alarm type & if it is set or not at time of measurement. 

 

Thanks man, Awesome. Will go ve it a go.