DL 650 killing batteries

[lazyboy]

I have a problem that neither I nor the local Suzuki dealer can diagnose. My 650 is on it's 3rd battery in 4 months. All seems fine for quite a while after a new battery is installed. I put it on a battery tender from time to time and it always shows fully charged within about 5-10 minutes. Charging rate always tests out at around 14.7v at 5,000 rpm. But now the 3rd battery in a row has gone dead - this usually happens after stopping somewhere on a ride. I normally get some indication beforehand that this is going to happen as starting takes slightly longer on pushing the starter button but it still starts relatively quickly up until the point where it is suddenly dead and will only turn the starter over very slowly or not at all. I'm not running any accessories - the bike is stock. Anyone got any ideas?

[silverstrom]

Perhaps your regulator/rectifier is the problem. I've seen cases where it will work fine for a while, but once it gets hot it stops working. Once that happens you start riding on the battery alone and when you stop the bike will die. The regulator/rectifier may test fine in the shop, but once it gets hot after a long ride it fails.

Stators have also been known to fail for no reason, even on newer bikes. I don't think that's your problem here, but something to keep in mind.


SS

[randyo]

Perhaps your regulator/rectifier is the problem. I've seen cases where it will work fine for a while, but once it gets hot it stops working. Once that happens you start riding on the battery alone and when you stop the bike will die. The regulator/rectifier may test fine in the shop, but once it gets hot after a long ride it fails.

Stators have also been known to fail for no reason, even on newer bikes. I don't think that's your problem here, but something to keep in mind.


SS

my thoughts exactly, I had an intermittent RR failure on my SV650, it was very hard to diagnose cause it worked perfect until it gt hot (30-45+ minutes of riding)

[ronin149]

I don't know what Suzuki's recommended range for the charging voltage is, but 14.7V is too high for ANY sealed lead-acid battery. This voltage will cause gas to be generated; pressure will build up & the vent will open. The battery will lose all of it's electrolyte in a short time. This would explain all of your symptoms.

It is possible that the meter you were using was reading high due to electrical noise. Any modern digital meter would most likely not suffer from this shortcoming, but old analog ones might.

If the voltage you are reading is correct, then a new regulator would most likely solve your problem.

I've had a bad regulator on my CX500 for over a decade. I know I'm lazy, but it's just easier to add water to the battery than replace the regulator. We don't have that option with a sealed battery.

[lazyboy]

I think 14.7 DCV is fine. I attach an excerpt from the manual which shows 14-15.5 DCV as the acceptable range. I've had a digital multimeter or a Signal Dynamics LED (green indicating 12-15 DCV charge rate) on the bike continuously while riding since installing the last battery 2 months ago. No problems showing at all with charge rate and the battery is still fine despite rain and washes. The only difference with this battery is I did the initial charge slowly as per manufacturers spec rather than letting the dealer fast charge it like the others. Still, I'm not convinced the problem won't re-occur - I had one of the previous batteries work fine for two months and then go suddenly also.

Still, right now all is OK with battery No. 4!

[Arne]

I think 14.7 DCV is fine. I attach an excerpt from the manual which shows 14-15.5 DCV as the acceptable range. I've had a digital multimeter or a Signal Dynamics LED (green indicating 12-15 DCV charge rate) on the bike continuously while riding since installing the last battery 2 months ago. No problems showing at all with charge rate and the battery is still fine despite rain and washes. The only difference with this battery is I did the initial charge slowly as per manufacturers spec rather than letting the dealer fast charge it like the others. Still, I'm not convinced the problem won't re-occur - I had one of the previous batteries work fine for two months and then go suddenly also.

Still, right now all is OK with battery No. 4!

Fast charging, if done incorrectly, is a great way to kill a battery. I'd even go as far as saying to not fast charge any battery if you don't have to. I agree that 14.7V DC is fine provided that the charging current is not too large.

[ozart]

I don't know what Suzuki's recommended range for the charging voltage is, but 14.7V is too high for ANY sealed lead-acid battery. This voltage will cause gas to be generated; pressure will build up & the vent will open. The battery will lose all of it's electrolyte in a short time. This would explain all of your symptoms.


I'm another in this camp, with personal experience. A good 12V charging system should never go above 14V.

[Big B]

I'm another in this camp, with personal experience. A good 12V charging system should never go above 14V.

Your battery won't ever charge, if it doesn't exceed more than 12v. My C14 consistently runs 14.4-14.6 as the voltage listed on my readout....this is normal, and my battery is charging correctly.

[ozart]

Your battery won't ever charge, if it doesn't exceed more than 12v. My C14 consistently runs 14.4-14.6 as the voltage listed on my readout....this is normal, and my battery is charging correctly.

It only takes 13.8V output to fully charge a 12V system, anything much over that is just poor/lazy design and destructive. *thumbs nose*

[msi1259]

I'm another in this camp, with personal experience. A good 12V charging system should never go above 14V.

I think this was true a few years ago, but newer batteries need higher charge voltages - a normal, vented battery will read 12.6 volts when read after full charge (stabilized off charger for a few minutes), while the lead-calcium sealed batteries (i.e. Yuasa MF) will read 13.0 volts (and are recommended to be charged at 14.8 <-> 15 volts when in the motorcycle). The Yuasa technical manual (http://www.yuasabatteries.com/pdfs/TechMan.pdf pg 30) shows charging at almost 17 volts in some cases. There is also situations (i.e. when the battery is discharged to very low), that the voltage has to be briefly taken to <25 volts to get the battery to charge properly (pg 35). Temperature also makes a difference on charge voltage - at near freezing it is has to be increased and at 122 F it has to be reduced, with ~1 volt difference from cold to hot.

[greywolf]

My old 1975 BMW R90S came stock with a voltmeter and a car like alternator/regulator system. The regulator adjusted the power to the field windings rather than shunting excess into heat. The manual said the voltage limit was 14.8V and that's where the needle stayed when the battery was at full charge. I had the bike for ten years on the same battery.

[PJungnitsch]

To the OP, put on a permanent voltmeter, so you can keep an eye on the volts as you go. Every vehicle should have one, IMO, it makes diagnostics a million times simpler.

[msi1259]

My old 1975 BMW R90S came stock with a voltmeter and a car like alternator/regulator system. The regulator adjusted the power to the field windings rather than shunting excess into heat. The manual said the voltage limit was 14.8V and that's where the needle stayed when the battery was at full charge. I had the bike for ten years on the same battery.

The pre-1981 BMW regulators were adjustable - and were suppose to be set at 13.7 to 14.3 volts (~14.0), while the police bikes had a special regulator set to 14.5 volts. (http://bmwmotorcycletech.info/boschmechreg.htm ). I'm guessing your meter was reading high - my airheads wouldn't put out 14.8 (with the headlight on), and would barely charge until about 4000 RPM.

[greywolf]

I'm only going by memory but I thought things were okay up to 15V being too much. What sounds familiar from there follows but I didn't remember the touring as opposed to commuting part. I might have gotten the 14.8V value from Chitech.

****For those doing a lot of commuting with short cycles of stop and go, it may help to reset things a bit higher. Note that with the following settings and longer touring, you might use up battery water faster. Those with sealed batteries may see less life on your battery. For commuting use:
Right contacts closure at 15.1; left at 14.3; the average value to be 14.7

I'm still surprised the DL650 manual says 14.0-15.5V is the accepted range at 5000rpm.

[ronin149]

Woah, I opened a can of worms with this one! One might think I said motorcycle oil is better than automobile oil! (or was it the other way around?)

Anyway, I stand by my statement. But I should probably clarify a few things:

When a battery is in any state of discharge, charge voltage is less of a concern. Sealed Lead Acid (SLA) batteries normally have charge voltages printed on the side. Unfortunately, the ones used in vehicles don't have this label. Anyway, the label states that for "cyclic" usage, 14.0-15.0V (typical) is the charge voltage. Cyclic usage is an industry term for "Get the thing fully charged as quickly as possible." One would apply 15V (current limited) until the battery was charged, then remove the charger before damage occurred. Also printed on the side of the SLA batteries is a maximum charge current. For a battery that is used on a regular basis, this current will be reached long before the maximum voltage is reached for any relatively deep state of discharge (below 75% state of charge.)

The voltage that I quoted was for a "float" charge, also printed on the side, typically 13.8-14.4V, temperature dependent. This is the maximum voltage that you can apply to the battery for an indefinite period of time. It will keep the battery fully charged without overcharging it. Any voltage higher than this will overcharge the battery. This causes two main things to happen: One, it generates heat. Two, it electrolyzes water, evolving hydrogen & oxygen gas.

Heat is generally bad for the battery but is usually not excessive while in a motorcycle. The electrolysis however will rob the battery of electrolyte & generate pressure within the battery. This could cause the vent to open & a permanent loss of electrolyte would occur.

The following figures back me up and is clipped from Wikipedia:

Voltages for common usages

These are general voltage ranges for six-cell lead-acid batteries:

* Open-circuit (quiescent) at full charge: 12.6 V to 12.8 V (2.10-2.13V per cell)
* Open-circuit at full discharge: 11.8 V to 12.0 V
* Loaded at full discharge: 10.5 V.
* Continuous-preservation (float) charging: 13.4 V for gelled electrolyte; 13.5 V for AGM (absorbed glass mat) and 13.8 V for flooded cells

1. All voltages are at 20 °C, and must be adjusted -0.022V/°C for temperature changes.
2. Float voltage recommendations vary, according to the manufacturer's recommendation.
3. Precise (±0.05 V) float voltage is critical to longevity; too low (sulfation) is almost as bad as too high (corrosion and electrolyte loss)

* Typical (daily) charging: 14.2 V to 14.5 V (depending on manufacturer's recommendation)
* Equalization charging (for flooded lead acids): 15 V for no more than 2 hours. Battery temperature must be monitored.
* Gassing threshold: 14.4 V
* After full charge the terminal voltage will drop quickly to 13.2 V and then slowly to 12.6 V.

There are two things that battery manufacturers do to mitigate this problem: First, there is always one more positive plate than there are negative plates. this does not preserve electrolyte, but does allow the battery to absorb a moderate overcharge without catastrophic corrosion from occurring. Second, almost all sealed batteries have a moderate ability to recombine the generated gases back into water. This is through the use of platinum catalysts and other proprietary methods. The ability of these methods to absorb overcharge is typically very limited.

So how does any of this help the OP, lazyboy? Well, he mentioned breaking down on "rides," which made me assume that he had been on the road longer than usual, giving the alternator (running at high speed) and faulty regulator ample time to overcharge and dry out the battery. Since others see similar voltages but not similar failures, this is probably not the problem. So what is? Hard to say without more information. If he lived closer I would have him come by so I could put an oscilloscope on it. Since that's not an option, I would say the next step is a voltmeter to see if the regulator is failing at odd times, when no one is looking; like silverstrom said. If lazyboy never has a problem again, I'd say it was the fast charging.

Like I said, I stand by my statement, and the voltages above are correct. So what's going on with Suzuki? I hypothesize that it has something to do with the way in which motorcycle alternators work. Having fields generated by permanent magnets, their output varies with engine speed. At idle, the alternator does not generate enough energy to run everything. The bike runs off the battery. At a few thousand RPM, it matches the load of the ignition, headlights, etc. Above that, it will have a surplus of energy and start to recharge the battery. I was intrigued by greywolf's RS90, & I have a friend that used to ride a boxer. His battery was always going dead. He also usually didn't ride far. Remember what I said about charging for cyclic usage? It's possible that with more lights, fuel injection, ABS, etc. it's harder to keep batteries fully charged at anything less than mach-chicken. The hotter charge voltage would compensate for this by charging the battery more rapidly when charge was available.

This would still cause a problem on a long, high-speed trip. I'm not the only engineer that knows this, so I wonder if the regulator rolls back it's charge based on time... I don't have a mounted voltmeter. Any feedback from someone who does? I'd expect the battery voltage to roll back from it's high to 14.0-14.4V over a period of hours.

It's also possible that the batteries specified for the 'Strom are designed to absorb the required amount of overcharge, which is not the same as "charging at a higher voltage."

msi1259, I checked the manual that you quoted. No where in there did they actually quote a float charge voltage that would be used in normal circumstances. (The insanely high voltages you quoted were special cases.) They did, however recommend two different battery chargers. Both of then were manufactured by Yuasa. Both of them peaked at 14.4V.

[msi1259]

<snip>
msi1259, I checked the manual that you quoted. No where in there did they actually quote a float charge voltage that would be used in normal circumstances. (The insanely high voltages you quoted were special cases.) They did, however recommend two different battery chargers. Both of then were manufactured by Yuasa. Both of them peaked at 14.4V.

I don't think motorcycles try for a float charge - the DL1000 service manual shows an upper spec on charge voltage of 15.5 volts, as does the Honda ST1300 - even though it has a car style (field) alternator. I'm guessing manufacturers figure the bikes are idling all the time and need to charge ASAP when they can? My DL1000 shows a consistent 14.8 volts, even after hours of riding.
I quoted "insanely high voltages" for emphasis that "A good 12V charging system should never go above 14V." is no longer true. Likely newer sealed batteries can handle quite a bit of over-charging.

[greywolf]

My voltmeter normally shows 13.9V when the battery has a good charge and I'm not using heated gear. If I haven't ridden in a few days it can show 14.4V for a few minutes and 14.1V for a while longer until it settles down to 13.9V.

[lazyboy]

Thanks guys - there sure is some good discussion going on here. Sadly I know my limits and some of you are way ahead of me on this topic. I do have an LED hooked up so I can continuously monitor the charge rate and it's always in the green but that only tells me it's somewhere between 12 and 15V. (Overcharge would be a flashing green indicating >15V but I've never seen that). The first failure was on a long, high speed ride of about 450km giving some credence to the overcharge theory, but subsequent failures have been after weeks or months of relatively short local rides. I wish I lived closer to Utah so I could take ronin up on his offer - maybe next spring if the problem persists! Would a battery specialist shop have an oscilloscope like you mentioned that I could get more detailed testing done? What would I ask them to be on the lookout for? Sadly I don't think the local Suzuki dealer has a fraction of the knowledge that is on display in this series of posts. Meanwhile I have my fingers crossed as this battery is into month 3 now, long may it live!

[Arne]

My voltmeter normally shows 13.9V when the battery has a good charge and I'm not using heated gear. If I haven't ridden in a few days it can show 14.4V for a few minutes and 14.1V for a while longer until it settles down to 13.9V.

Is that 13.9V with the bike idling or off?

[Boondocker]

Any chance all your batteries came from the same batch? If so, maybe you're replacing defective batteries with defective batteries from the same bad batch.

Other than that, the charging discussion was real interesting until my eyes started to glaze over from information overload.

I have a digital voltmeter (one of the cheap $25 jobs with clock and temperature) - my favorite instrument by far. I did notice that my battery, less than one year old, doesn't hold as high a charge since it was discharged completely once. Thank you parking lights feature. It used stay at ~13.0v for a couple of days (parked in garage), but since the discharge event now only holds at about 12.5v. When riding, the voltmeter is normally at 14.3, no accessories. I routinely leave it on the Battery Tender if I know I'm not going to being riding for a couple of days.

If I make the same dumb mistake of turning the parking lights on and discharging the battery again, I'll replace it. These batteries don't tolerate complete discharging without being compromised.

[greywolf]

Is that 13.9V with the bike idling or off?Idling and at speed. No battery will show that with the engine off.

[ronin149]

Would a battery specialist shop have an oscilloscope like you mentioned that I could get more detailed testing done? What would I ask them to be on the lookout for?

Unfortunately, the kind of diagnostics I had in mind are going to be hard to get out of a regular shop. They simply could not turn a profit if they went that route; too many hours invested in the repair. They would prefer to replace parts until they found the right one. Less time & they aren't paying for the parts.

What I had in mind was just probing around the charging system looking for anything that should not be happening. I prefer the 'scope as it shows more than a voltmeter does. It takes time and might involve sitting around drinking beer, watching the bike run for long periods of time; all the while holding a hairdryer on the regulator. This is no way for a shop to make money (but a hell of a way to spend a Saturday!)

If the problem persists, we can address it. I think you may have it fixed now, though.

All this talk makes me wonder if my old CX500 regulator actually isn't bad. It puts out between 15.0-15.5V, depending on engine speed. It would however run a battery dry on a long trip, had to top it off every thousand miles or it would dry up and die.