Battery Life

[uncledj]

  I'm heading out on a trip with friends up to the cabin, and going over the bike, I decided to put a new battery in it.   Haven't ridden for a month or so and the battery was dead.   Charged it up, then went for a 1/2 hour ride to get it charged up;  put the bike back in the shed and 2 days later it's weak.   Down to 9.7 volts.   So I replaced it.   It was a year old AGM,    NOT on a tender, and I've now replaced it with a lead-acid.

  I've had this bike since 2012 and I think there was only one year that I didn't feel the need to replace the battery.   

  I've done the basic checks, making sure any accessories are disconnected when she's sitting, but the problem persists.   Is there a common issue that would cause the slow drain that's killing these batteries?

  Not a major issue, but I"d like to get it resolved.    Now that I've put a lead-acid battery in it I'll leave it on a tender again, but it's aggravating when you turn the key and nothing happens.

  

[Freebird]

Well, it does seem a bit extreme to be down to 9.7 volts after only a couple of days.  I know that they will go down due to things like the clock and etc. but I didn't think it would happen that quickly.  I can't say for sure because I always leave mine on a battery tender, regardless of the battery type, all the time.

[RDawson]

I went through one per year on my 86 using lead acid. Went to AGM and got 5 years out of the last one never using a tender. Seems a little extreme. 

[WildBill1]

I've got up to (8) years out of my AGM's using a battery tender occasionally.  I use Deka brand batteries in my bikes.

[saddlebum]

I am currently on year eight with my Deka AGM and it is still going strong. Generally keep on a battery tender through the harshest winter months but I have had years where I have forgot to hook it up and I never disconnect the battery from the bike, yet still the bike would just barely crank over. I would then put it on the battery tender overnight and it would be good for another season.

If it is dropping off as fast as you say I would suspect a parasitic drain condition try disconnecting the ground cable from you battery when you store the bike and see if it still occurs.

Edited August 3, 2022 by saddlebum

[uncledj]

  Yeah...moving forward, I think I WILL disconnect the battery in the Winter.   Would still like to know what's draining it.

[cowpuc]

1 hour ago, uncledj said:

  Yeah...moving forward, I think I WILL disconnect the battery in the Winter.   Would still like to know what's draining it.

@uncledj,, hi Unc!! I agree with you,, I would definitely want to know whats causing the drain too, I dont trust Murphy and KNOW he would get me at just the perfect time so here is what I would do. I would turn off the ignition and pull the fuses one at a time and do an amp test with my multi meter across the open circuit where the fuse was. Any amp draw higher the 30 or 40 milliamps I would be concerned with.  Dont forget to check ALL fuses including the main. I would also look closely at the voltage regulator/stator system in the same way. I had a regulator allowing AC thru slightly that ended up being the cause of what your dealing with.  I also had a similar experience with a fried terminal where the 3 wires from the stator connect to the wire harness on the frame of one of my MK1's. If your riding a 2nd Gen, which I believe you are, another cause could be the ignition switch itself. If memory serves me correctly (getting old brother,, memory lapses are not that uncommon these days) the 2nd Gens are known for ignition switch issues? Maybe even do a amp test at the battery leads while flicking the ignition on/off and watching the meter. One thing for sure,, it dont take much of an errant draw to drain a bike battery and it is really NO FUN when Murph takes the slight draw and turns it into an instant dark in the middle of the night while crossing the desert 2000 miles from home lol.. Love ya! Puc

[saddlebum]

20 hours ago, uncledj said:

  Yeah...moving forward, I think I WILL disconnect the battery in the Winter.   Would still like to know what's draining it.

The way I test for parasitic draw disconnect the ground cable. hook a multi-meter set to the 10 amp setting between the ground cable and ground post. If the reading is more than 1 amp start pulling fuses until the amp reading drops. If the initial amp reading is less than 1 amp switch to the milliamp scale. Anything above 50 milliamps indicates a parasitic draw. Again start pulling fuses until it drops. Once you find the fuse that drops the reading reinstall it. Next find the any connectors to which that fuses circuits run through. The minute you pull a connector apart and the reading drops off reconnect it and go to the next connector. if for example the next connector or connectors make no difference than than you have a short some where between the two connectors. If however the second or third connector do make a difference continue to disconnect subsequent connectors until your down to the end of the circuit or circuits. Next disconnect the items that circuit powers up until your meter shows no draw.

NOTE: if you do not have a multi meter a test light  or bulb and pig tail makes a reasonable substitute. Connect one end of the test light to the neg battery post and the other end to the disconnected cable. If there is no draw the light should be off  (or very dim due to things like clock and radio memory voltage). But if it is glowing even if not full bright  Follow the same steps as above  until there is a significant drop in the brightness of the bulb.

[Marcarl]

10 hours ago, saddlebum said:

The way I test for parasitic draw disconnect the ground cable. hook a multi-meter set to the 10 amp setting between the ground cable and ground post. If the reading is more than 1 amp start pulling fuses until the amp reading drops. If the initial amp reading is less than 1 amp switch to the milliamp scale. Anything above 50 milliamps indicates a parasitic draw. Again start pulling fuses until it drops. Once you find the fuse that drops the reading reinstall it. Next find the any connectors to which that fuses circuits run through. The minute you pull a connector apart and the reading drops off reconnect it and go to the next connector. if for example the next connector or connectors make no difference than than you have a short some where between the two connectors. If however the second or third connector do make a difference continue to disconnect subsequent connectors until your down to the end of the circuit or circuits. Next disconnect the items that circuit powers up until your meter shows no draw.

NOTE: if you do not have a multi meter a test light  or bulb and pig tail makes a reasonable substitute. Connect one end of the test light to the neg battery post and the other end to the disconnected cable. If there is no draw the light should be off  (or very dim due to things like clock and radio memory voltage). But if it is glowing even if not full bright  Follow the same steps as above  until there is a significant drop in the brightness of the bulb.

SMART!!! Where did you learn that now?

[saddlebum]

13 hours ago, Marcarl said:

SMART!!! Where did you learn that now?

If I had learned it within the last 55 years I could tell you but prior to that I don't remember much. But then I am sure you understand exactly what mean, Don't you.

[Marcarl]

12 minutes ago, saddlebum said:

If I had learned it within the last 55 years I could tell you but prior to that I don't remember much. But then I am sure you understand exactly what mean, Don't you.

Don't have any idea what you are talking about...did it happen today or yesterday and where was it when it flew away.

[saddlebum]

1 minute ago, Marcarl said:

Don't have any idea what you are talking about...did it happen today or yesterday and where was it when it flew away.

What flew away

[Marcarl]

20 hours ago, saddlebum said:

What flew away

I don't know, I wasn't there.

20 hours ago, saddlebum said:

What flew away

 

[saddlebum]

58 minutes ago, Marcarl said:

I don't know, I wasn't there.

 

Are you sure or do you just not remember being there. where ever there was

Maybe it was there somewhere in between the U turns! Somewhere

Edited August 6, 2022 by saddlebum

[uncledj]

  Just got back from a few days up the cabin with friends   Had a GREAT time....rained every day, but not until we were done riding.   I never got wet.   Had NO issues with the battery....a slight issue with a hangover...   Nothing better than lifelong friends around a campfire with beer and cigars.

Edited August 8, 2022 by uncledj