parasitic draw? (pt II)
So Im trying to troubleshoot a potential parasitic draw.
A perfectly good battery isnt able to start my bike after sitting for a week or so.
I don't believe its my charging system (stator, r/r) since it puts out 13+v while idling. I think my battery is getting a charge.
So. Last night I check my battery before going to bed it reads: 12.87v
This morning I check it before going for a ride: 12.75v
That means I have a drain somewhere, No?
After riding around for the afternoon I check my batter a third time (with the ignition off): 13.03v
That means my charging system is working, right?
So, this is what I did to test it. Please let me know if I've done anything wrong!
The display reads 1.31 (See picture below)
I have no idea what that means!
Is it good? it it bad?
Did I even do it right?!
Any insight would be greatly appreciated!!!!
PS, yes this is kind if a dupe post of this:
While that post helped get closer to understanding, I decided to start another thread since my testing started from scratch.
Chris from NY
The easiest way to tell if there is a current leak somewhere is to check voltage of the battery with either the negative or positive disconnected (doesn't really make any difference) and then again, with it connected. The bike must not be running and the key turned off. If there is any consistent difference between the two readings then chances are that indeed you have a current leak, or "draw" as you call it somewhere.
These bikes do have a small draw when off. Regardless of battery type or what you do you need to have it on a charger once a month if not riding. As for testing you did it right sort of. However whenever you disconnect the batter then reconnect it the ECU goes back through it's Idle Stepper Motor parking process to setup for the next start. To do this correctly you need to allow enough amperage to go through that then measure. It's easiest with a clamp style amp meter. As I recall my bike draws a few hundred ma always.
So what that display on the meter is telling you is that the bike is drawing 1.31 milli Amperes. Yes, your connection looks proper as the only way to properly read amperage is to break the circuit and have the meter become part of the closed circuit, which you have done by disconnecting the battery and inserting the leads between the battery and the ground wire.
Make sure that you *only* do this with the bike off, as even in the on position with the engine off, you'll likely exceed the current rating of the meter and blow it.
1.31 mA is not a very big draw at all. Likely whatever power the speedo is drawing to keep your settings and clock on time. This does not account for your battery drain as a 7 amp hour battery could supply a 1.31 mA draw for about 3,700 hours or about 155 days before depleting completely.
Sounds to me like one of 3 things:
1) Your battery is old and weak;
2) Your battery is defective and has a high internal draw;
3) Something is wrong with your bikes charging system and its not actually charging the battery when on.
What is your voltage reading across the positive and negative terminals with the engine at idle and at about 5-6 thousand rpm?
Sent from my SM-G950W using Tapatalk
Thanks so much for the explanation!
Follow up question.
"a 7 amp hour battery could supply a 1.31 mA draw for about 3,700 hours or about 155 days before depleting completely"
Would you explain the arithmetic to that?
Is it 7 / .00131 = ~5300hrs?
I ask because I'd like to better understand Amps, miliAmps and Amps hours...
7amp hr battery means it can supply 7 amps at 12 volts during 1 hour; 7 x 12 = 84W for an hour.
0.00131mA x 12V = 0.01572W draw; if the battery can do 84W for an hour it can do 0.01572W for 5340hrs, or abt 220 days. That's how I usually calculate loads on batteries; I always do it that way when sizing UPS batteries. This is also an oversimplification because it doesnt take into account the power lost as heat in the battery, the 7amp draw on the battery will cause it to heat up... And these are not deep cycle batteries, if you were to discharge them all the way like that you'll kill them.
How long ago did you replace that battery? Has it been severely discharged in the past? A couple deep cycles are enough to turn a brand new battery into a weak 3 year like battery. Trying to start the engine when the battery is weak only damages the battery more; if you ever notice it is weak either push start the bike or put it on a charger.
Watch the video below. Yes it is car based, but the concept applies to motorcycles as well. He does a very thorough job of showing what needs to be done to test for parasitic draw. Mac pointed out something very important in regards to the ECU and stepper motor. In the video he describes something very similar and waiting a little bit for everything to "time out". I used this video to find the parasitic draw on my daughters VW beetle after an aftermarket radio was installed. FWIW VW used the left, rear negative speaker wire as the sense wire to turn off the stock built in amplifier. Something the aftermarket radio couldn't do.
|All times are GMT -4. The time now is 10:09.|
Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.