Battery Troubleshoot

[fiedler.casey]

Hey all,

I was riding just the other day, on only the third or fourth ride of my new build, when suddenly she bogged out and refused to rev at 55 in 6th gear. She ran right down to nearly nothing and sputter and putted along at what was nothing more than a coughing idle in first. Initially I suspected lack of fuel from carbs but it turned out not to be the case.

As I started looking more closely I realized I'd lost all electrical, apparently she was running erratically on the power provided by the low RPM output of the charging system. None of the lights (headlight, speedo backlights which are LED, turns, Voltmeter, etc) function off the battery. I did some tests and found that a test light was also erratically lighting up when connected directly to the battery posts. It would flicker, then nothing, and after moving the leads around on the post the test light would flicker again, light up fully, and fizzle out over and over again.

After these test results, I hooked the battery up to a battery tender which went from red, to blinking red, to solid green within 5 minutes, leading me to believe the battery must be holding charge...

Voltmeter tests show ~13.3V consistently without erratic readings from (-) to (+) terminals (after the battery tender charging was applied). I tried hooking up the 12V headlight directly to the battery posts using alligator clips and the headlight will not draw enough current to light up. The test light is erratic or non functional even with the battery completely removed from the bike and sitting upright on the bench.

The battery is an 8Ah 12V AGM battery from DCC purchased ~12 months ago and kept on a battery tender almost exclusively.

I did ride the bike for ~20 miles or so on the first test ride without the battery fully secured. I.E. there was about a 1/4" gap between the battery and its mounting assembly which allowed for some vibrational movement. I know this because I realized it was a problem when I saw small flecks of plastic around the battery from where it had rubbed and chaffed on the metal housing around it. The chaffing did not, however, breach the battery's plastic outer housing and there is no leaking evident anywhere. I have since secured the battery mount more properly.

I am afraid that perhaps the inaugural test ride jiggled the battery's internals apart somehow... I'm really not sure what else would explain the erratic function.

Does anyone have any suggestions on where I should go from here? Battery tests that may prove more conclusive?

Thanks!

 

[Sonreir]

Take the battery to a dedicated shop and they'll usually run the tests for free. Definitely possible that too much vibration killed it though.

 

[frogman]

If your battery will not light a headlamp at an indicated 12 or higher volts it is shot, possibly shorted internally. You are reading a surface voltage that I bet goes away after a while. You have voltage but no amps and you need both to do work.

Your battery charger saying its charged in 5 minutes its saying the battery can't take any more voltage, that doesn't mean its actually charged fully.

Smaller than stock batteries are more susceptible to being overcharged. Check your charging systems both on the bike and your charger. Make sure both are doing what they should, especially your float charger. I've cooked a battery or two leaving them plugged in when they really didn't need it. If you are riding at least once or twice a week you shouldn't need to plug it in. If you have to plug in every night just to get it started the next day you have major problems.

 

[fiedler.casey]

Got a new battery. Things are looking up. However, I am afraid the charging system is over charging the battery. The maximum voltage I have measured across the battery terminals is 14.44 V with a sustained revving of the engine. Is this too high of a charging voltage for a small sealed battery? What about charging current? Is it possible that the charging system is dumping too much current in to the battery too quickly and causing it to damage?

 

[raptormeat]

14.4V is good voltage to be charging at. i believe higher than 14.8 ish causes gases to build up inside the battery.
basically your charging system is good and i dont think it is damaging your battery.

 

[mydlyfkryzis]

Since we don;t know what kind of bike you are talking about, it is hard to give specific information. On the Small Honda twins (350,360,450) the regulator from Honda was spec'ed 14.5 Volt +/- 0.5 Volts. So you could see as high as 15.0 Volts. A modern regulator will keep it around 14.5, which is as said earlier, Ideal for lead acid batteries (including AGM)

The lithium batteries are another story.

A fully charged lead acid battery (Conventional and AGM) is 12.6 volts when standing. A fully discharged battery is 12.0 Volts. If the standing (not loaded) voltage is below 12.0 volts, the battery is damaged. The plates may be sulfated or other damage.

 

[fiedler.casey]

Alright, picked up a new battery.

http://www.amazon.com/gp/product/B00IUV7YNW/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1 This one, on the cheap from Amazon.

From the readings I have gotten so far, it seems that the charging system is putting out a R/R-ed voltage of 14.44 even at idle and stays steady through the range. It also seems to be putting out ~3A of current which doesn't really appear to increase noticeably through the rev range.

The bike is drawing about 5A without any accessories turned on (light, horn, etc). Seems like too big of a draw to me. Any input on that?

I might be wrong but it seems to me that 3A of current in to the battery with 5A being spent without accessories means there's no way the charging system can keep up with the demands of the bike.

I have been reading that high charging current can kill a small battery (like mine). So, is 3A too big of a current to charge my battery? Am I frying it?

The R/R is from a late model Honda, 6 wire. I have it wired in with each of the three stator wires going to an individual yellow wire at the R/R. My understanding is that if I wire the yellow/pink from the stator together into one yellow from the R/R I will get more current output from the R/R because it connects two partial windings?

Also, to answer questions the bike is a '75 CB 360 with a completely re-done wiring harness. I am suspicious that part of the 5A draw I'm seeing at idle without accessories my be one (or multiple) wiring inefficiencies on my part. Perhaps not.

 

[mydlyfkryzis]

Sounds like you might be measuring wrong. The alternator is a current generator. Not a voltage generator. Output varies with RPM linearly. The voltage regulator does not regulate the voltage like a car. It only keeps the output from exceeding 14.4 volts. At idle, a good output with normal loads is 12.5 volts. As revs pick up, so should volts. When the output reaches 14.4 the regulator starts shorting the ac output to ground, so it won't exceed 14.4

Coils draw about 3 amps stock. The 3 ohm coils draw about 4 amps. Headlight is about 3 amps. The rest draw an amp or so. Any left over is for charging.

How are you measuring amps? Ammeter needs to be in series with the load. If you have it wired correctly, a charged battery will have 0 amps. This assumes the ammeter is only between the battery and the other 2 wires. You would be reading net amps.

Pics would help figure out what you are actually reading

Sent from planet Earth using mysterious electronic devices.

 

[Sonreir]

Alright, picked up a new battery.

http://www.amazon.com/gp/product/B00IUV7YNW/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1 This one, on the cheap from Amazon.

From the readings I have gotten so far, it seems that the charging system is putting out a R/R-ed voltage of 14.44 even at idle and stays steady through the range. It also seems to be putting out ~3A of current which doesn't really appear to increase noticeably through the rev range.

The bike is drawing about 5A without any accessories turned on (light, horn, etc). Seems like too big of a draw to me. Any input on that?
The R/R is from a late model Honda, 6 wire. I have it wired in with each of the three stator wires going to an individual yellow wire at the R/R. My understanding is that if I wire the yellow/pink from the stator together into one yellow from the R/R I will get more current output from the R/R because it connects two partial windings?

What color are the other three wires? Green, red, and black?

With a three wire R/R, you won't see any bonus from splicing the white and yellow wires (not the pink and yellow).

 

[fiedler.casey]

Thanks for the clarification on the 3-wire R/R, that's what I have.

I did a little more tinkering and have found that when the DVOM is wired properly in series between the battery and the fuse panel there is a .4A current being drawn from the battery when the bike is on but the kill switch is off (all accessories off). When the kill switch is turned on, the current draw goes up by ~3A. Then, when the bike is running, the current drops to -.4A at idle.

I take this to mean that the charging system is, then, dumping more current into the battery than the bike is drawing and, therefore, .4A is flowing back into the battery?

Is .4A an appropriate amount of charging current for this battery?

When I rev the bike I am not seeing a change in that current reading though, to be fair, it is fluctuating quite drastically between -.2A and -.5A when the bike is running. Should I be noticing a change here, or do I need to rev the hell out of it and sustain high RPM to see a change?

Thanks for all the input.

 

[Sonreir]

I prefer to measure voltage. Amps are the true measure, but voltage usually makes a bit more sense as it's what we usually see.

If your voltage at 5,000 RPM stays between 13V and 14.4V, you're usually good to go.