SuzukiSavage.com - Battery drain after charging.

LS650THUMPER

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Battery drain after charging.
05/28/16 at 10:33:37

Not sure if this has been covered. After bringing Battery to full charge, bike runs ok...seems to loose a bit of charge over a few days..Lites dim, weak horn. Etc !! Bike runs with jump, use anything electrical and dies. 1.check battery ground at frame. 2. Could rectifier be bad?..3. fuses are ok. Did have issues with right side connection under tank. After looking at it,was able to correct it... replaced license plate lite a few years back... recently move rear directionals to plate.

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verslagen1 YaBB Moderator ModSquad Offline Where there's a will, I want to be in it. Posts: 28886 L.A. California Gender:	Re: Battery drain after charging. Reply #1 - 05/28/16 at 10:43:56 bat to old to hold a charge? voltage at 4000 rpms?
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justin_o_guy2 Serious Thumper Offline What happened? Posts: 55279 East Texas, 1/2 dallas/la.	Re: Battery drain after charging. Reply #2 - 05/28/16 at 11:07:31 How old is the battery? Does it need water?
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Armen

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Re: Battery drain after charging.
Reply #3 - 05/28/16 at 13:59:59

Generally, a battery that goes flat over a few days is either a weak battery, or a parasitic load.
Get a digital volt/amp meter. With the key off and the meter in the DC Amps position, connect the meter between the negative terminal of the battery and the ground lead.
Meter should read zero, unless you have some gizmo that draws juice. I've seen a bunch alarms that started out drawing 3-5 millampers, and later got cranky and started to draw a lot more. Enough to flatten a battery.
Bikes with electronic speedos will draw some juice, but not much.
The other big culprit is the regulator rectifier. A bum diode can flow both ways and flatten a battery. If you see a draw on the meter, try disconnecting the reg/rect leads and see if the draw goes away.
If it isn't the Reg/Rect, then pull out one fuse at a time until the draw goes away.
If all looks peachy, reconnect the battery and switch the meter to DC Volts. Put the meter across the battery leads and hit the starter button. In decent weather, the voltage shouldn't drop below about 10 1/2 volts.
If it does, the battery is on it's way out.
-Armen

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Dave YaBB Moderator ModSquad Offline SuzukiSavage.com Rocks! Posts: 18099 Camp Springs, Kentucky Gender:	Re: Battery drain after charging. Reply #4 - 05/29/16 at 04:04:20 Charge the battery, disconnect the ground lead, then let it sit for a day or two and connect it back to the bike......if it is discharged then you know it is the battery that is causing the problem.
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Armen Serious Thumper Offline Half-Witted Wrench-Jockey from Jersey Posts: 1452	Re: Battery drain after charging. Reply #5 - 05/29/16 at 06:18:51 Unless a shorted rectifier or bad regulator toasted the battery. Then it is both issues, and you'll be buying another battery soon. Yup, seen that a few times. A decent digital meter is pretty cheap. When all else fails, do it right. -Armen
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Savageman Senior Member Offline Knowledge is half the battle Posts: 275 Marysville, California Gender:	Re: Battery drain after charging. Reply #6 - 05/29/16 at 12:16:07 2 things come to mind. Measure voltage at the battery when engine is running at about 3000 to 4000 rpm should read 14.5 to 15.3vdc. Buy a new battery if charging voltage is good. I prefer the AGM type batts. Seem to hold up pretty well. Don't buy a cheap battery.
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LS650THUMPER

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Re: Battery drain after charging.
Reply #7 - 05/29/16 at 17:13:17

Ok I busted out my ole radio shack analog tester... battery is from 11/15 bought new sealed lead acid.. tested negative post and lead, got 0 on meter.. placed on POS and NEG post got 15 + reading. Started bike and read 15+ didn't drop .I did go over a lot of connections, so will retest tomorrow and see if there is a drop. Tried all lites and horn, no drop.

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Armen

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Re: Battery drain after charging.
Reply #8 - 05/30/16 at 13:14:53

Sounds like your meter is junk.
Never saw a battery read 15V.
Never saw one not drop under load.
12.7v is normal for lead/acid batteries. A little higher for Gel. A little higher for LiIo.
Most bikes with a healthy battery will drop to the 10-11.5v range under starting load.
Most bike charging systems do 13.8-14.5. A lot of early Suzi-Q systems will charge at 15.5. Which is why they blow up Lithium batteries unless you change the R/R.
-Armen

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Kris01 Serious Thumper Offline Eat, sleep, RIDE! Posts: 3767 Tennessee Gender:	Re: Battery drain after charging. Reply #9 - 05/30/16 at 15:50:43 It is possible to read over 15V but if the starter is running, it's putting a load on the battery and will definitely drop the voltage.
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Armen Serious Thumper Offline Half-Witted Wrench-Jockey from Jersey Posts: 1452	Re: Battery drain after charging. Reply #10 - 05/30/16 at 15:54:29 Must be a parallel universe. In 40 years of working on bikes I've never seen a bike battery read 15 volts.
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LS650THUMPER Junior Member Offline SuzukiSavage.com Rocks! Posts: 64 Ma Gender:	Re: Battery drain after charging. Reply #11 - 05/30/16 at 17:59:30 Dead again after short trip. Any idea on cost of rectifier.. stop by dealer tomorrow.. can a older 87 ish work. Bone yard close too...
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Kris01 Serious Thumper Offline Eat, sleep, RIDE! Posts: 3767 Tennessee Gender:	Re: Battery drain after charging. Reply #12 - 05/30/16 at 19:13:59 Armen wrote on 05/30/16 at 15:54:29: Must be a parallel universe... Maybe not on a motorcycle charging system (they're usually weaker) but I've seen 1 or 2 read slightly over 15V on a car/truck.
Back to top	There's no problem that a full tank of gas and a sunny day can't fix! 2008 S40, Rotella T 15W-40 w/ZDDP added, Dyna, 140/90-15, Battery Tender Jr., Seat lift, #52.5/150/3 washers, Raptor IP Logged

Kris01 Serious Thumper Offline Eat, sleep, RIDE! Posts: 3767 Tennessee Gender:	Re: Battery drain after charging. Reply #13 - 05/30/16 at 19:16:06 LS650THUMPER wrote on 05/30/16 at 17:59:30: Dead again after short trip. How short? Maybe you aren't riding fast enough/long enough to charge the battery?
Back to top	There's no problem that a full tank of gas and a sunny day can't fix! 2008 S40, Rotella T 15W-40 w/ZDDP added, Dyna, 140/90-15, Battery Tender Jr., Seat lift, #52.5/150/3 washers, Raptor IP Logged

Dave

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Re: Battery drain after charging.
Reply #14 - 05/31/16 at 03:49:49

LS650THUMPER wrote on 05/30/16 at 17:59:30:

Dead again after short trip. Any idea on cost of rectifier.. stop by dealer tomorrow.. can a older 87 ish work. Bone yard close too...

Rectifiers are cheap.......eBay has them for $ 20...new or used.

I still don't think you have done adequate testing to know if your battery is any good.....or if the charging circuit is at fault.

Charge the battery, connect it to the bike, use a voltmeter and take readings. What is the voltage when you have the battery connected in the bike, what is the voltage when you hit the starter button - what is the voltage with the engine running and revved up a bit. If you don't see the voltage increase a bit when the engine is running......then the charging circuit is not working. Could be the rectifier.....or the stator, and there are tests you can do to find out - but first you need to prove that the system is not charging (voltage test described above).

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