Low bat = freak out

[B.D.F.]

Yeah, 78 milliamps is too high as a sustained rate. I have checked several C-14's and they have all been amazing close- initially a bit higher than 75 milliamp (probably exactly the 78 you found) and then the current draw drops to just under 2.5 milliamps where it stays as long as I have bothered to check.

Thirty seconds sounds like more than enough too, going by memory. I believe it was more like 10 seconds on the bike's I've checked but again, I do not remember and I never did actually measure the time while I was doing it.

Perhaps you had a shaky connection somewhere between the meter and the battery and / or battery cables? If so, it could have momentarily dropped out and reconnected at which point the whole boot up procedure would have started again and it might have appeared to be a steady current draw? Just a wild guess.

Brian

Wait a min, that is 78mA!  That is way too high (for some reason I was thinking 7.8mA).  I waited for the initial bootup draw to finish and watched it settle on 0.078A for about 30 sec.  Was that not long enough???

[B.D.F.]

Agreed, and in actual testing, the initial current draw is around 78 milliamps but drops to ~2.5 milliamps shortly (maybe 10, maybe 15 seconds after original power up).

Brian

78mA is way too much for everything being "off". 

I once installed a car stereo with a LED clock (long time ago), and wired the acc and hot together.  It's draw when off was about 100mA (clock display was on all the time), and it would drain the car battery to the point it would not start the car in a couple of weeks.  Probably wasn't the greatest battery, but still, without that draw, it would still start after months of sitting.  I ended up adding a micro slide switch on the front of the unit so I could turn it on to check the time without using the key.

Has anyone else measured the draw from the battery when everything is "off"?

[B.D.F.]

Yes it does go off, and the manual says that it is done to save battery power but honestly I cannot imagine that that LED is really a big deal. I doubt it draws 20 milliamps (which in itself would be rather a lot of steady drain) but it is only on, what?, 1% of the time? It blinks very briefly every six seconds or so, so the actual average current draw would be well under a (ONE) milliamp. Nothing wrong with saving power on battery operated vehicles (it would be great if they could sit and draw -0- power but it isn't going to happen) but there is a line where battery loss from current draw is much less than self- discharge and I am sure that red blinking LED is below that level.

Brian

That little blinky red light goes off after 24 hours doesn't it?

[B.D.F.]

Nah, not me Jim- I am way to impatient to do 24 hour experiments or tests. I would have to speed things up by artificial means. Like they do with hard drives- when they give a mean time between failures of 500,000 hours it is interesting because hard drives have not been in use for that long. They are extrapolating the test by increasing the temperature and (probably) vibration and then projecting how long the drive will last under normal use. I would have to do that with the 24 hour experiment: hook up the ammeter, record data for a while until bored, then speed things up by increasing the ambient temperature probably by setting the bike on fire. Take the final current draw (from the ashes), note how long it was at what rate, then divide the average temperature of the bike on fire by the initial temperature and there you have it.

Brian

Brian (BDF) has verified that but all are welcome to verify.  Max, you could do a search and find it.  I think Brian has talked about it before in this incarnation of the forum.

[maxtog]

Well, it has now been 24 hours on the charger and the charger is still solid red.  The instructions said it should start blinking green once at 80%.  If the charger works as described, have pushed 17AH into a 14AH battery that was nowhere near dead to start with and still not even at 80%.  Not good.

I am now starting to worry about overcharging (something that using a smart charger should not allow, unless it or the battery is defective)....

I have to take the bike out for a ride now,  messing up the test.  But I will slap it back on the charger when I get back.  I figure at around 750mA, another 12 hours or something can't be too dangerous.  I hope.

[VirginiaJim]

I just ride mine and stick it in the garage afterwards, no charger.  Guess I've been living dangerous for the last 5 years...

[B.D.F.]

Take that whole charging amp- hour thing with a grain of salt. You will always find that batteries overcharge and some amount of that is perfectly normal on a healthy battery. The excess power will just show up as heat from the battery although you probably will not even notice much of a temp. increase.

Remember that lead - acid batteries are quite tolerant of a long- term, mild overcharge. They simply turn the energy into heat and radiate it away. The chemistry will eventually reach a peak after which the battery will take more current (energy actually) but not turn it into any more acid, just heat.

If you have a voltmeter around check the voltage of the battery while on the trickle charger- if it is not over 14.4 volts or so I would not worry about it. Then again, I believe the better battery tenders have both charging and testing periods so a voltage reading might not mean much. You could also check current but of course you have to interrupt the circuit and therefore the charging cycle to do that unless you are nimble with the wires (seriously- it is possible to jumper in an ammeter and then break the original connection while keeping the ammeter in circuit).

But as Jim said, I just ride mine and then let it rest (OK- I ignore it). I charge mine the old- fashioned way... I ride it. :-)  Besides that, there is the school of thought that says a battery tender may mask a weak battery by not allowing it to self- discharge until you are away from the tender at least overnight; put another way you are increasing the likelihood that you will strand yourself far from home.

Brian

Well, it has now been 24 hours on the charger and the charger is still solid red.  The instructions said it should start blinking green once at 80%.  If the charger works as described, have pushed 17AH into a 14AH battery that was nowhere near dead to start with and still not even at 80%.  Not good.

I am now starting to worry about overcharging (something that using a smart charger should not allow, unless it or the battery is defective)....

I have to take the bike out for a ride now,  messing up the test.  But I will slap it back on the charger when I get back.  I figure at around 750mA, another 12 hours or something can't be too dangerous.  I hope.

[gPink]

Can you try it on a differant battery?

[VirginiaJim]

Well, it has now been 24 hours on the charger and the charger is still solid red.  The instructions said it should start blinking green once at 80%.  If the charger works as described, have pushed 17AH into a 14AH battery that was nowhere near dead to start with and still not even at 80%.  Not good.

I am now starting to worry about overcharging (something that using a smart charger should not allow, unless it or the battery is defective)....

I have to take the bike out for a ride now,  messing up the test.  But I will slap it back on the charger when I get back.  I figure at around 750mA, another 12 hours or something can't be too dangerous.  I hope.

Maybe instead of a smart charger, you have the evil charger.....guaranteed to ruin your battery.  I've seen at least a couple of them smart chargers go bad (evil).

[maxtog]

All good suggestions/info.

I will test more tomorrow (or soon).  Just got home from a 30 + 30 min ride to my friend's house.  Wow what a powerful start when it came off the charger!

Jim: It is brand new and supposedly quality, so the odds of the charger being "evil" seem low.  I don't have the opportunity to ride that much, for many reasons; so it can sit a week or more unused.

Gpink: Good idea.  I might try it on my car or something and see how it works there.  Although that will require pulling back the wire going through the wall to the outside where the bike is.

Brian: Thanks for the info.  Kinda what I was thinking- especially hard to do too much damage with a puny 750mA charger on a lead acid.  But you made me more confident to let it go for a while and see what happens.

[C1xRider]

Max,

  You can measure the current out of the battery after 24+ hours (long after it should be in its low power state) with your meter as long as you don't break the electrical circuit when you disconnect the battery cable from the battery.  To do this, make sure the meter leads have a good connection to the battery post and the battery cable end.  It might be easier to measure at the point where the negative cable connects to the frame.

  I've done this type of thing many times in other situations, and it's easy provided you plan everything in advance.  Make sure you have the meter connected in a 'hands free' way (like with good alligator clips) so when you remove the cable from the post, the circuit remains - through the meter.

[maxtog]

Yes,  I should be in bed... took a nap earlier and going now (2am!)  I checked and the light is FINALLY GREEN!!!!

[robbie]

Have you checked the connections? I keep mine on a Battery Tender while I am away. I had too many batteries killed by sitting too long. I travel so my bikes sit at times. I had an RC51 and its batter was $170. I wen through three before I bought the Battery Tender. I am on my original 2009 C14 battery. I keep it plugged in.

+1...I'm on my original '09 as well. I always keep mine on a tender and its still going strong. My last bike I did not keep on a tender and a battery never lasted more than a year to a year and a half.

[VirginiaJim]

Yeah, but look at the color of your bike.

[sunpa]

I have an '08 and did an "off" battery drain measurement soon after I got it in Oct '07.
Results: 170mA for ~1 sec; 90 mA for 10 sec; then 2.5 mA ...
I repeated the test a couple of times with consistent results. Did not wait to measure after 24 hr.

I believe the 750 mA is probably the max rating of your battery tender and it probably tapers to much less charging current as the battery voltage comes up. Also the tender red light may be staying on so long because the excessive drain in your bike makes it "think" that the current is going into the battery.

[maxtog]

I have an '08 and did an "off" battery drain measurement soon after I got it in Oct '07.
Results: 170mA for ~1 sec; 90 mA for 10 sec; then 2.5 mA ...

I admit that my test might have been flawed.  Maybe I was seeing that second time period and just didn't wait long enough to see the third.