A little confused, charging problem?

[kairles]

Well for some reason my bike didnt want to start today. Check the battery and it was low(11.7v). Charged it up, then did a test on it with the bike idling its at 14.5v. Bring the revs up to 5500rpm and it drops to 14.0, then back at idle it go's back up to 14.5v. Did the same thing with the high beam on and at idle and 5500rpm it hovers around 13.5v-13.8v.

This seems kinda weird to me. Last time i check it(couple months ago) idle was about 13.5v 5500rpm was about 14v. Battery is only a couple months old, as is the rectifier(but i am on #4).

any clues?

 

[IG.]

What you are describing is perfectly fine. I have a V-meter permanently wired to the battery, so I know. You probably didn't ride too much lately, and the battery lost some charge. If you have an alarm installed that would drain the battery over a period of time even more.

If you don't ride for a while, put the battery on a float charge. Let me know if you want more info.

 

[kairles]

thats the thing I ride every day to and from work(about 30min each way). yesterday it started fine going to work and when I left work.

 

[IG.]

Fully charge the battery. Check the voltage. It should be at least 13.0 V, and it should stay in this range for hours (don't turn the bike ON). If it drops to 12.6 shortly, your battery is no good.

OK. Here is the thing, to start your bike you crank it about 1 sec - that's about 80 Amps x 1 sec, or 80 x (1/3600) Ah = 0.02 Ah. When you ride for 30 min, the charging current fluctuates, but it's not great - maybe 0.1 Amp. So, in half hour that would be 0.1 Amp x 0.5 hour = 0.05 Ah. Considering the charging is not 100% effective, you barely recover what you spent on starting the bike. If you stuck in stop and go traffic, and the fan kicks in a number of times, the bike may be losing charge as I observed at those times the voltage drops to about 12.5V.

If your bike has an alarm, it drains at least 5 mA, and slightly more when armed. So, in 24 hours that would be 0.005 Amp x 24 hours = 0.12 Ah loss.

So, if you actually charge the battery once, and then ride every day, your battery will be slowly losing charge - about 0.1 Ah per day. More or less depending on various factors I mentioned. So, after a few weeks or a couple of months you get to the point when seemingly all of a sudden you cannot start the bike and scratching your head.

If you want to know more about installing the V-meter, I will provide details.

 

[kairles]

I guess that kinda make sence. I dont have an alarm, but I do have a bazzaz and HID's. The last 3 days its been taking a while(5-8seconds) to start, but it always cranked over like normal. took a while to start because it needed new plugs, changed those today.

thanks for the info , will see how it goes on the ride tomorrow.

 

[GIXERHP]

What is your measured voltage during cranking?
You could have a dead cell in the battery!

 

[kairles]

What is your measured voltage during cranking?
You could have a dead cell in the battery!

11.1v during cranking.

checked this morning its at 12.7v road the freeway for 20min check it and it was at 12.6v. I came home turned the bike off and checked again still at 12.6v. Could the battery be on its way out?. I checked again with it running and its at 13.0?v at idle and 14.0?v at 5000rpm. turn the bike off and it slowly drops from 13v to 12.7v

 

[IG.]

11.1V during cranking is pretty good. My new one is around 10V during cranking. Now, having 12.6V right after riding (and considering that while you ride it's at least 13.0V, and with higher rpm is more than that), this is not right.

Something isn't right. First off, the fact that you crank for 5 - 8 sec doesn't help the issue, but this alone can't make it so bad.

Let's think. You got a new battery. They are pretty good these days, so it's hard to suspect the battery. But... do this experiment for me...

Disconnect the battery from the bike, charge it with a charger like overnight, or for a number of hours, and then see what happens with the voltage. If you don't have a charger, ride that baby for a while or idle - just make sure the voltage is good. Disconnect the battery as soon as you turn the bike off. If disconnected battery doesn't hold it around 13V for a few hours, than something is not right with the battery. Maybe it wouldn't be a bad idea to go to a shop and ask them to charge the battery instead of you doing it. $10 or so I am guessing.

Now, if the battery checks out OK, then I would say something is draining the battery when the bike is OFF. It's a bit tricky to measure with a Amp-meter because there is a sudden surge of current when you connect the Amp-meter, and you either burn the Amp-meter or the fuse inside it. The safest way to do it... Well, you know let me know if you want to do it, and I will give a bit more detail. The fact that you have HID's makes me suspicious because I've heard of HID's draining batteries when the bike is OFF.

Also, if the HID's draw more power than regular lights, this puts an extra load on a charging system, and thus may provide less charge to the battery, or even draining the battery at idle or when the fan is on.

It's all not so complicate. You just gotta eliminate one thing at a time. So, let's make sure you battery is good first.

 

[kairles]

I charged it to just over 13v but as soon as I take the charger off it drops down to 12.7-12.8 with in 2 minutes. but is hasnt drop any lower all day. I did check for a draw. My GIpro is pulling almost 7mA, took it off and it droped to 0.8mA. For the last 10 or so hours its held at 12.7 with the GIpro connected.

I changer the plugs yesterday and adjusted the idle. Starts after about 2 seconds now.

Im gonna charge the battery out of the bike and swap in one out of my other bike and see if it acts the same.

 

[chrisjp]

charge it!!!!

 

[IG.]

I charged it to just over 13v but as soon as I take the charger off it drops down to 12.7-12.8 with in 2 minutes. but is hasnt drop any lower all day. I did check for a draw. My GIpro is pulling almost 7mA, took it off and it droped to 0.8mA. For the last 10 or so hours its held at 12.7 with the GIpro connected.

I changer the plugs yesterday and adjusted the idle. Starts after about 2 seconds now.

Im gonna charge the battery out of the bike and swap in one out of my other bike and see if it acts the same.

Again, are you talking about a battery that's disconnected from the bike, or still connected? If it is still connected, there could be something that draws the power when the bike is OFF. The only way to know is disconnect the battery and to charge it.

Putting the battery from another bike will only mask the problem. If fully charged, it may seem like everything started working fine - problem solved. However, as time goes by and let's say something draws extra current when the bike is OFF, the problem will re-appear again.

When you say your GIpro is pulling 7ma, you probably mean that you measured the current in the wire which goes to GIpro only. This is not the draw for the entire battery - there are other wires connected to it, right? That includes the main harness. You need to measure the total current drawn from the battery when the bike is off. Again, this is a bit tricky. But, we are jumping hoops here. You have to establish one fact at a time. And the first one is establish whether your new battery is losing, or holding the charge when not connected to anything. So, disconnect the battery from everything, and whatever charger you have, charge it for like 5 hours - don't worry, it's not going to damage the battery. It's like you are riding all day. And then let's see what happens.

Other than that, your battery seems to behave like my 6 year old one which I replaced recently (or maybe it behaves like not fully charged one). I came from a day's ride yesterday, and this morning it's still 13.2V (new one).

Also, you cannot charge it to just over 13V. This is simply the Voltage you see while charging. If I connect my cheepo Harbor Freight charger, the voltage gradually increases and after a while stabilizes around 15V. Again, just because the voltage reached that level, it doesn't mean the battery is chraged. A small charger may provide charging current of 0.3A max. This means that for your 9Ah battery which let's say lost half the charge (4.5Ah needs to be charged), you would need to keep it charged for 4.5Ah / 0.3A = 15 hours - see what I mean. Vehicle batteries are designed to be charged indefinitely and not going bad. Think about it, when you put a fully charge battery in a vehicle, and then drive for 10 hours straight, does this damage the battery?

I would keep it like that for a few hours. Another alternative - I got a float charger from Harbor Freight, and this one keeps constant 13.2V no matter what - this one can be left connected for days - no harm because as the battery voltage rises to 13.2V, the current become negligible - that's why it's called float charge - it will only compensate for the natural loss of power, but will not actively charge the battery - that's what you might want to consider for in between rides.

So, to summ it up. Step 1: check the battery first. If this checks out, then Step 2: check the the total current drawn from the battery when the bike is OFF.

 

[kairles]

I have a maintainer, I charged it off the bike. before I put the battery in the bike it was alittle over 13v.

I check for a draw at the battery. disconnected negative and put meter in line. meter read 7.4?mA. I disconnected the Gipro because the power wire is right there. with it disconnected meter read .8?mA meaning my GiPro is drawing almost 7mA.

I was gonna swap batteries(didnt get to it yesterday) to see if it was the battery. my old battery was always at 13.?? with the bike off(I know because I had to test it alot) after putting this 14s in I never really checked it.

thats way its kinda confusing. I know a new battery is usually 12.6v but in a car/bike its usually just over 13v after its run and should hold. My charging system seems to be working, but I do have a 7mA draw. after running the bike battery is at 13.?? but drops to 12.7 in less than 5 miutes and holds that all day and all night.

 

[Professor]

A lead acid battery is 2.1 volts per cell. You should see 12.6-12.8 volts when fully charged. It is common for them to be a bit higher after a full charge. It still should drop to the 12.6-12.8 volt numbers after a while with no load on it.

 

[IG.]

My old one (6 year old, and it was getting weak) behaved like this - would drop to 12.6 - 12.8 after a few hours, but the new one takes a few days to a week to go back to 12.6V.

OK. So, assuming that the battery seems OK, and the draw of 7mA is not a big deal, I would consider a possible combination of the following factors.

1. If you didn't put the battery on any kind of active charge in between your rides, and assuming you've been cranking the starter for 5 - 8 sec, that alone may drain the battery. If we adjust my rough calculations in post#4, a 6 sec crank would drain your battery by about 0.12 Ah. A half hour ride pumps back aroun 0.05 Ah - not enough to replenish. As days/weeks go by, and considering the fact that sometimes you need to restart the bike more often (like when getting gas, running to the store), this eventually depletes the battery enough so one day you can't start the bike. So, maybe all you need to do is to reduce your cranking time (which you did), and by putting the battery on maintenance charge once in a while.

2. HID's may affect the charging system, so the battery doesn't get enough charge while you ride. The only sure way of confirming this would be to install a V-meter on the bike which you can observe while riding. Something like this... I have it installed in my left upper, right on top of the fuse box (straight to the battery via the fuse - it draws about 0.7mA so no need for switch), so whenever I see the voltage getting low, I know I need to charge the battery, and I can easily observe the voltage while riding (e.g. sitting in traffic idling, and with the fan ON, the voltage drops to about 12.5V, normal riding - around 13.5V, idling with the clutch pulled in - around 14.5V). I used a potentiometer to calibrate it with digital V-meter to be precise at 12.6V.

RadioShack® Panel Meter 0-15VDC - RadioShack.com


3. Something (and again HID's are the first suspect), drains the battery when the bike is OFF, but not necesserily all the time.

 

[Wrath]

" Fully charge the battery. Check the voltage. It should be at least 13.0 V, and it should stay in this range for hours (don't turn the bike ON). If it drops to 12.6 shortly, your battery is no good."

I don't agree with this statement however, battery voltage is 12.6V. if your at 13V then you have what's known as a surface charge. When testing battery you ALWAYS remove the surface charge from the battery by pulling a quick load on it or by leaving the lights on for a min or so. 12.6 volts is a fully charged battery. In Order for your alternator to charge, you need 1 Volt higher than battery voltage. Electrical Law states it take 1 volt to push 1 amp through your battery. so your alternator needs to be pushing 13.6V to be actively charging. Now if the battery is in a fully charged state, the alternator can drop lower as at this time it is really only suppling power for the bike to operate.

 

[IG.]

The battery not holding what you call a surface charge is the first sign that either the battery is getting bad/old or there is a load on the battery.

13.2V (less than 13.6V) will be charging the battery, but with a lesser current than the higher voltage. My Harbor Freight charger can only supply 0.3A max, but after a while the voltage goes to about 15.0V, so 15.0 - 12.6 = 2.4V difference should be pushing 2.4Amps through the battery which I don't believe is the case - the charger would've burned. If I disconnect it, the voltage quickly goes to about 13.5, and then very slowly drifts down over a period of days.

I am not aware of the 1 volt - 1 Amp law. What does it mean? Again, if I connect my small charger to a battery which has 12.6V, the voltage will go to 13.6V within about 30 min, but there is no way this small charger can provide 1Amp of charging current as it would've burned - as a matter of fact it is barely warm which is an indication of a pretty small current.

The alternator is not smart enough to "know" whether the battery is fully charged or not, and will behave the same way regardless of the state of the battery.

BTW, it's Tuesday, and my new battery is still at 13.0V of "surface" charge after my Sundays ride. And I did turn the gauges ON to get some reading, and the voltage dropped, but after I turned the bike off, the voltage recovered back to be higher than 12.6V.

The original poster got a problem somewhere, and it is likely to be a combination of the things I mentioned as neither his battery, nor his charging system seem to be out of order, even though I am still not 100% sure about his battery.

 

[kairles]

Well my battery pretty much stays at 12.7v. I was able to do a load test on it. On a 230cca load it dropped to 10.6v when the load was off it bounced back to 12.6v and test came back as good battery. Put it in the bike and it started right up.

Sent from my Droid

 

[IG.]

Great! Just keep an eye on the battery for a while, especially a few hours after each ride. Seems like it was simply a combination of factors leading to a discharged battery.

 

[kairles]

yeah thats what im thinking now.

still kind of puzzled why it stays at 12.7v, do AGM batterys act different then regular lead acid batterys?

 

[IG.]

My new is AGM, and likes to stay around 13V for a long time. That's what I got:

NEW YT12A-BS GSF1250S Bandit GSX1300R Hayabusa BATTERY: eBay Motors (item 180480038492 end time Nov-06-10 16:03:32 PDT)