Lithium Battery Blues

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rocketdoc

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A year ago I replace my second OEM battery on my '04 FJR with a Lithium battery. Lighter and full of cranking amps, I was initially very pleased. I also installed a Voltmeter at the same time. Running along at 3,000 rpm plus the volmeter shows12.9-15.1v.

I found it odd that the voltmeter would show lower 12.7-12.8v when the turn signals were on and when the radiator fan came on, it would almost always show 12.1-12.6v . The biggest issue I am having is when I have been touring, into a town looking for a place to eat or stay we traditionally cruise up and down the mainstreet checking out each potential spot. (The three of us take turns picking the place) whether it be a restaurant or a motel, we do the routine. If I turn off my bike when the radiator fan has been running and find the restaurant to be a dump, or moving onto the next motel, it will turn over as if the battery is flat, then on repeated attempts in a few seconds start the bike. However the trip meter and clock reset as if the battery has been disconnected. My riding buddy thinks it is a voltage regulator or a generator/stator problem. I am not that up to speed on electrics and think perhaps he is right, or my battery is just a dud.

So what does the collective FJR mind think about this? Suggestions to diagnose and resolve the issue would be much appreciated.

Want this fixed.

Rocketdoc

 
Which battery is it? That voltage pattern is all wrong. The bike should be at around 14 volts when running. Exactly what voltage depends on where you measure.

 
I've been running a Shorai lithium for about 2 years. I have their 18 AH (amp hour) model. It registers about 13.1 -13.3 most mornings when I get ready to start the bike, and the temps are above 40. Colder temps have quite an effect on lithiums as I have documented on this forum. This "resting" voltage, about .5 volts higher than lead/acid batteries, is normal for lithium batteries. Once running, the bike quickly heads for about 14.0-14.1 where it stays all the time it is running. This is the normal voltage you should see on any FJR with any battery. Running voltage is not determined by battery type, but by the FJR's regulator. All batteries should have the same voltage when fully charged and the bike is running.

I'm curious, why do you mention the turn signals? They use a VERY small amount of wattage and should not be a factor in this kind of discussion. Your wording was a little tricky to understand, but you seem to be saying that you have a .2 voltage drop when you turn them on. This is not normal. Then it appears that you're saying that voltage drops as low as 12.1 with the radiator fan on. Though the fan uses a great deal of power, your voltage with the engine running should NEVER drop to 12.1. This is dangerously low for a lithium and will probably hurt the battery.

One question I would like to ask the forum here: if the radiator is continuously running in continuous bumper to bumper traffic in hot weather, is it normal for the battery to be going into a discharge state? Is the alternator not able to keep up with the current draw of the radiator when the engine is idling? What kind of amperage does the alternator deliver at idle?

Also, you said that when running, voltage shows 12.9-15.1... my first thought was that the only time your bike should run at 12.9 with the engine is running is a second or two after it starts, as the battery is charging. But 12.9 is rather low for a lithium, even in those first few seconds after charging. Your battery should be at a minimum of 13.3 within seconds after starting and heading quickly toward a max of about 14.1-14.3. However, it should NEVER reach 15.1; this number seems extremely high to me. Forum, am I right about that?

Hope that helps.

Gary

darksider #44

 
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I strongly suspect the voltage isn't being read at the battery terminals (you must run wires from both battery posts to the meter, with no other loads on those wires, only perhaps a fuse and relay contacts), or it is a poor voltmeter.

...
Once running, the bike quickly heads for about 14.0-14.1 where it stays all the time it is running. This is the normal voltage you should see on any FJR with any battery. Running voltage is not determined by battery type, but by the FJR's regulator. All batteries should have the same voltage when fully charged and the bike is running.

... Forum, am I right about that?

Gary
darksider #44
Pretty much right, but ...

With my OEM Yuasa, after starting and with cold idle of around 2000, voltage rapidly (maybe 5 - 10 seconds) goes to 13.9 - 14.1.

At warm idle it drops to around 13.5, will only get up to 14 if the revs go up to 3000 or so.

Any extra load will drop the voltage, as an example, sitting waiting for my garage door to open just now, hot idle, lowering my screen, the voltage dropped to 13.2 from its 13.5.

From experience, indicators, brake lights, heated grips, heated vest all cause a decrease in voltage, even with the revs at 4000, though in any combination and normal riding, I don't recall seeing it drop below 13.0 even at idle.

The system has behaved like this at least since I put a voltmeter on it some 3 years, 28000 miles ago, near enough from new.

I've checked all connections on mine, there's nothing wrong with any, but I won't say it couldn't be better regulated if I redid the wiring from regulator to battery.

But, the way I look at it, any voltage above 12.8 at the battery terminals means the battery is being charged, since its off-load idle voltage isn't above that figure.

And I don't understand why, during cold idle it reaches 14, but won't reach that after warming up but putting the engine revs to the same value.

I don't worry about it, it's these little mysteries that help make life interesting, and I've never had a problem with it, even only using the bike for little 2-mile shopping trips for days in cold weather, and the battery had plenty of charge to deal with a flooded, WOT, seems-to-take-forever start.

 
I've checked all connections on mine, there's nothing wrong with any, but I won't say it couldn't be better regulated if I redid the wiring from regulator to battery.

And I don't understand why, during cold idle it reaches 14, but won't reach that after warming up but putting the engine revs to the same value.
+1 on the connections from RR to battery.

The hot voltage may be lower because resistance increases as temp climbs.

 
Even measuring voltage at, say, the accessory plug, the OP values are out of whack. Especially notice the very HIGH voltage seen at times.

I know the first instinct is that it's your charging system, but I know of at least one battery that can cause these kinds of voltage excursions. Specifically I observed this in an EarthX battery, which has unique circuitry to balance the charge across cells. When I reported it, I wound up talking to one of their engineers, who immediately said the "smart" circuitry in my battery was faulty. They replaced it with another and no problems since (a few months).

EarthX has a 2-year warranty. If you have one of these you probably have the same problem mine did.

 
Save your money and go buy a Yuasa AGM - the 5 pounds you saved by going lithium-iron won't make any measurable difference in the bike's performance and you will find it cranks better when cold and, even if you need to replace it sooner than you might have with this newer technology, cheaper. Besides, the bike's regulator is designed for use with traditional battery chemistry.

 
I have a 2 lb 5 oz 18 amp Shori in my 2012 FJR for two years no issues . Important is no static draw/drain when the bike is off . Its in the instructions/website . So a meter directly to the battery would cause a static draw that slowly drains the Li batt. Some people are not concerned about weight , but others are OEM was 12 or 14 lb located in the fairing . My battery lives under the seat now = lower center of gravity teamed with all the other weight savings on my bike make a very noticeable difference.

Interstate is a Shori dealer , and they could test / properly charge the unit for you . Battery has a two year warranty if I remember correctly .

One day AGM's will not be around ( not soon but will be one day )

 
The only time I've seen low and high voltages like that turned out to be a loose positive battery terminal connection. Flummoxed me as I cleaned every terminal and main ground, checked Regulator/Rectifier failure symptoms, etc. Last thing I did (before starting recent thread on my stupidity) was put a screwdriver to the battery terminals. Only then did I finally figure out the root of my intermittent discharge issues (interspersed with the high readings on my radar detector's voltmeter.) Doh!

Not saying that's your problem, but it is worth double checking - low and high readings sure confused the heck outta me.

 
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