Battery volts

I'm reading about 13.1 -13.3 V while riding.

I remember it used to be up around 14... which is why I wanted to check.

What gives here- old battery or alt going bad?

To the best of my knowledge battery has not been replaced by previous owner, I have not replaced it.

Voltage reading is the standard setting i use for the dash.
Expected voltage (note that the dash always read some tenths of voltage lower than the actual, i thing up to 0,7v lower):

At key on (withought starting)
12,8v : fully charged battery
11,9V : almost empty battery

Start button pressed, starter is spinning the motor:
voltage drops no lower than 10v : normal, deppends on current draw, affected mainly by mottor (oil) temperature
less than 10v maybe 9,5v : battery kind of weak, anyway not at its best
8,5v or less (?) : battery almost empty, you'll be lucky if the motor starts...
note, low voltage reading at the dash, during starter operation, even with a fully charged battery, is an indication of bad ground contact. Can be verified by measuring the voltage at the battery conectors, using a voltmeter. Big voltage drop reading at the dash and small voltage drop at the battery = bad contact

When the mottor runs:
13,5v to 14,5v : charging voltage from an almost empty to fully charged battery.

Before changing an empty battery, give it a good charge with a charger. Riding the bike may not be enough to charge an empty battery - even a charger may need some hours to fully charge it.

Pulled battery from bike. It is at ~12.6V

Ill put it on the 1 amp charger overnight and see if it makes a difference. I don't think so.

Ok,
So riding it last week, I had the dash voltage while running at 12.7-13.1 V-

Much lower than expected.

I don't think the battery has been replaced since 2012-

Is it time to bite the bullet and get a new battery?

When It was on the trickle charger, I could hear it clicking 'on and off' every few minutes.

Signs of an old tired battery is it won't hold voltage or charge. 12.6v isn't bad. IMHO, if you're not seeing over 13.5v when running (preferably verified with a separate volt meter) then your charging circuit isn't working correctly as it should be between 13.5-14.5 regardless of your battery condition. As others have suggested, check the alternator belt and also all its connections for corrosion/tightness. If still low and the dash matches a meter then you have some sort of alternator or related issue.

OK, here goes. A "normal" automotive system (bikes are included in this too) is designed to charge a standard 12 V lead/acid battery to its full potential. This is achieved by a nominal (I mean this is what it should be, but there are variations...) 13.8 V charging circuit - sometimes a little lower, sometimes a little higher.

What affects this is a number of things:

- Firstly there is the main earth. As shipped, our bike are earthed underneath the stud holding the top of the starter motor cover. This is not a good spot, though it is easy to get to. If you over-tighten the stud you risk the case of snapping the stud thread in the aluminium, or stripping the aluminium. A better spot is the clutch housing bolt just above this point - you will need to make the holes in the lug a little larger (tapered reamer or a round file is best).

- Secondly, the charging system must be seen to be working. Recently mine was not charging, and it turned out to be one of the main fuses (2 side by side) - one runs the bike from the alternator, once started; the other charges the battery. My fuse was not blown, but did have dirty contact - probably getting worse over the 10 years I have had the bike. Test your charging with a multi-meter (these can be purchased for around $40 at any hobbyist store - if you don't have one, you should get one and learn how to use it, it is an invaluable tool to have in your man-cave, apart from yourself). When the bike is running you should see a number on your dash indicating "some" voltage. This varies for the simple reason that the wire used is minimal in its diameter and connections age with time, causing resistance and therefore voltage drop (or loss) - eventually showing less than the reality.
The voltage on your battery is the real value and will have a value at idle. This value should increase with revs. If not, firstly check the fuses. If still no joy, yes you may have a problem with your alternator/rectifier/regulator. Remove it and take it to a good auto electrician - It is the same (Denso) as fitted to many tin tops.

- Thirdly, after both of the previous points, your battery may be inclined to "exit stage left". Batteries do not last forever - this is a fact - some last a little time, some much longer. Lead acid (and its variants: (Gel, AGM) are at the bottom of the pile of batteries - they are selected for their ability to start your beast at the least possible cost - this is a fact of life. If you suspect you have a crook battery, take it to your friendly local auto electrician to test - it will either be good, bad or marginal. If it is not good, battery purchase time. This is reality.

- Where to from here? I carried out some research some years back on Lithium batteries. I don't mean Lion or their variants, I mean LiFePO4 (Lithium Iron Phosphate). These have been around for more than 20 years, though mainly in the military arena. Today they are available to you and I for not much more than the Yuasa Lead/Acid battery. These are around 20% of the weight of a typical L/A battery, have up to 50% more Cold Cranking Amps (CCA - the bit that spins your motor up, from the starter, until it runs), are around half the size, should hold a charge up to 1 year (this is not really possible when connected as there is a small load on your battery at all time when turned off), and should have a life approaching 10 years. However the quality of these LiFePO4 batteries is widely variable. Shorai, I found (the hard way) are made from discarded poo, don't go there. when time comes to replace your battery, think on this technology. HOWEVER, IF YOUR CHARGING SYSTEM IS NOT WORKING PROPERLY, THIS NEEDS TO BE SORTED FIRST. An ideal charging regime for LiFePO4 batteries is 14.2 V for a full charge - you might need to properly charge these batteries once or twice a year, to ensure they a full topped up.

Rant over. If anyone has specific questions, happy to answer them

Thanks Tony. I think I almost understood that. When it comes time, I'll get a LiFePO4.

I can't recommend LiFePO4 batteries for the GRiSO highly enough. You'll save weight and have a little stash hole under the seat. Also, the engine practically starts before you finger even touches the button.

Hey Tony, seeing as my bike starts and runs quite well with discarded poo (Shorai), should I go all out and fit the hydrogen converter with a flux capacitor?

I totally flattened it once thru abuse/neglect, it took 3 days on a charger to stir it back into life.
Now it drops from 13.6v to 12.8v over a 3 month period with zero use. Recharge and wait to see if I ride it in the next 3 months ...............................
Oh I should mention, I'm using the smallest amount of discarded poo as the size Shoria recommended, wouldn't fit in the Batmobile.

Wayne, you are lucky you got your Shorai back in business. I had 2 fail here at work, both were sent back to the distributor, response: "they be fecked, unrecoverable, not under warranty" - admittedly I wasn't using them as a power-sport battery, but I would have thought a better response may have been forthcoming. That's life, as they say in the movies. Have also been reports of "fragile" posts - they do look fragile, though...

I use a 12 A/H or 14 A/H (can't remember which) instead of the 20 A/H as specified with a Yuasa.

As for the rest, I am not saying you have to get a LiFePO4 battery, just saying it is a better option than the bottom dweller that is the L/A variety.

beetle wrote:

I can't recommend LiFePO4 batteries for the GRiSO highly enough. You'll save weight and have a little stash hole under the seat. Also, the engine practically starts before you finger even touches the button.

I've been told they give significant issues during cold winters though. Do you have any experience with that?

All batteries suffer in cold weather.
LiFePO4 however, operate in an entirely different manner.
In sub zero conditions the first stab of the starter may elicit minimal response. But that action causes it to warm up internally. Catalytic, chemical, nuclear reaction? Whatever (Tony please explain?)

Wait a few moments and the second stab of the starter gets a better response .............
Again, wait a few moments then repeat.

Eventually the warming process gives it the needed wherewithal to do what no Lead Acid battery could achieve in the same circumstance.

However, living in sunny QLD I cannot test the theory, but check this out;

LiFePO4 batteries have a negative temperature coefficient, whereas Lead/Acid have a positive temperature coefficient.

What this really means is that, in the case of a positive temp coeff, when the battery heats up (you tried to start your favourite bike) the internal resistance increases. THis means that the first start is the best you will get from it - every subsequent attempt to start will have weaker energy available from the battery. This is a self fulfilling prophecy and eventually the battery will not have enough left to start your engine BECAUSE of the additional internal resistance (higher resistance = less current flow, or CCAs).

The negative temp coeff batteries rely on this internal heat to LOWER the internal resistance. So the first start is the worst and they get better (more current/CCA) as the temperature increases.

Hope this helps.

motor-timothy wrote:

I've been told they give significant issues during cold winters though. Do you have any experience with that?

No problems here. However, I haven't ridden it in temps below about 10 degrees C.