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What killed this PC680?

Brantel

Brantel

Well Known Member
My original PC680 lasted about 2 years of storage/building and 2 years of flying.

Its failure mode was to be able to charge very quickly up to full voltage but it had very little capacity. It would almost instantly drop down to low voltage with only a light load applied.

I replaced that battery in Oct. of 2012 and the replacement battery has fully failed today with the same symptoms. Last week it started acting like it was going to die and today it gave up the ghost. (with 3 of those months being panel upgrades and tests)

It has the same issue. It will almost instantly charge up to full voltage but it does not have any capacity to do any real work.

I took it to Advance Auto and they tested it with their tester and they said it only had 35% of its rating in capacity left.

I have always used the Odyssey Ultimizer 6amp charger. I keep it attached nearly all the time the plane is in the hangar. My aircraft electrical system runs at 14.3 to 14.4 volts in flight.

So what killed these batteries that are suppose to have a long life cycle?
 
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My money is on the fact you keep it on the charger "nearly all the time the plane is in the hangar"
 
Brantel,

There's an EAA Webinar on battery maintenance that I believe they have archived. You might be well advised to listen to it. I need to listen again to clarify a few things but what I got out of it was keeping a glass mat battery fully charged is a good thing but you need to be careful about how you do it. Apparently even a trickle charger will over-charge. The guy giving the webinar makes some specific recommendations about how to accomplish it.

The gist of the problem is, when you run a sealed, maintenance free battery down, you need to recharge is slowly and apparently there's points where the speed of the charge changes. If you charge too fast, either by using most conventional chargers or (worse) by letting the alternator recharge your battery, gas is produced and is vented. This loses some of the potential to store energy. Each time you do it you lose a little more and since it's maintenance free you can't add more fluid.

The bottom line is you need to get the right "smart" charger for your battery to maximize its life. I believe they're right, too. I have been doing this with a Concord RG35 battery and I got 12 years out it.

Now, other than my one experience, this is all second hand info and I'm 99% sure someone will disagree with me, which is fine. My only advice here is find and listen to the EAA webinar and make up your own mind.
 
Guys,

I am using the charger made for these batteries and sold under the same brand. They actually recommend that the battery be kept on this charger.

Right off the Odyssey website (I use the 6 amp version):

auto_chargers.jpg


charger_3stepchart.gif


Straight from the battery manual:
"To get long life from the ODYSSEY battery, it is important that the battery is kept near full charge, approximately
12.8 volts. If there are electrical loads during storage, then the negative battery cable should be disconnected or an
independent float charger used. Low power 2.0 amp chargers for storage charge will keep a fully charged battery fully
charged but cannot recharge if the ODYSSEY battery becomes discharged."

Straight from the charger manual:
"The charger then enters into the trickle
charge phase at 13.5-13.8V. The battery can be left connected to the charger
indefinitely."

&

"TRICKLE CHARGE MODE: When the
CHARGED (green) LED is lit, the charger
has started this mode. The battery can be
left connected to the charger indefinitely
without hurting the battery."
 
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I am on my second PC680 in almost 7 years. The first one lasted about three years and I used a regular car batt charger on occasions to charge it. With my current PC680, I use a trickle charger and keep in plugged in most of the time in the hangar.
I have heard from various people and on VAF that these batts work best with slow / trickle chargers. It's been working well for me. I recently left an ignition switch on which drained the batt down to about 4 volts, charged it overnight and it still works great.
 
flyer174 said:
Soooo.....Im guessing by this post you didn't get to fly this morning?........
Click to expand...

No, my vacation day to do some flying turned into a troubleshooting session....you know, pull cowl, check all the easy stuff first/clean all connections/check all points of failure before accepting that the battery is toast. The auto store pretty much confirmed the witch is dead.

The good news is that BatteryMart.com is handling the warranty and these things have a 2 year non pro-rated warranty....bad news is the downtime till the next one gets here.
 
Do you have any "Keep Alive" circuits in the plane, or is the battery truly off when you kill the master??
 
:rolleyes:
Mike S said:
Then, why do you keep the battery on charge all the time??
Click to expand...

Because that is the recommendation of the manufacturer for long life...However I did get in this habit back when I had a Dynon legacy based system which did have keep alive inputs...

Maybe this is what killed it but if so, I don't get why all of the literature from the maker says it is ok and recommends the practice. I would have never done it if they had not recommended it.

When the new one gets here I will do the opposite and see what happens...
 
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Being the good neighbor that I am ill let ya fly mine and start getting used to a constant speed prop if your going to be around this weekend.......
 
flyer174 said:
Being the good neighbor that I am ill let ya fly mine and start getting used to a constant speed prop if your going to be around this weekend.......
Click to expand...

Now how can you beat that???

I am out of pocket tomorrow due to a "Bush Employee Golf Tournament" that I must participate in...(notice I did not say "play in", I am not sure you could call what I do on the golf course "playing")

Too bad I don't have the prop yet or I would just go ahead and make the swap while waiting on the new battery.
 
Brian, for what it's worth and it's very anecdotal...

Last fall my PC680 started slow after maybe 3 weeks of no flying. I put a charger on it after that flight and it worked fine through the winter. Come March it acted the same way. No charger would do anything to it though.

It was about 4 years old and had never needed a charge. It was replaced... Life is too short for dead batteries.
 
I have been watching the EAA webinar related to battery care and feeding as suggested above.

Many many times this guy talks about how good it is to keep your battery on a proper trickle charger. My charger is made for my battery and I have tested it during trickle mode and it falls right on the recommended trickle charge voltage.

All this real world aversion to the recommendations of the folks that are suppose to be the experts leaves me feeling unsettled about this issue. :confused: Like Sid said, life is too short for batteries that don't work when you need em!
 
I've got one you can use

If you can get up to KVJI, Abingdon VA, I've got one that's still got some life you can use. I just pulled it before my motorcycle crash and its on my bench in my hangar.
 
Brantel said:
I have been watching the EAA webinar related to battery care and feeding as suggested above.

Many many times this guy talks about how good it is to keep your battery on a proper trickle charger. My charger is made for my battery and I have tested it during trickle mode and it falls right on the recommended trickle charge voltage.

All this real world aversion to the recommendations of the folks that are suppose to be the experts leaves me feeling unsettled about this issue. :confused: Like Sid said, life is too short for batteries that don't work when you need em!
Click to expand...

Brian,

My PC680 has been in service for seven years and never had a trickle charger on it. Well...there was the one time a few years ago when I left the master on for ten days.....the battery recovered after charging overnight. I fly on average every week and have never had reason to think the battery is going down between flights.

One characteristic of these batteries is their ability to hold a charge. I wonder what the rationale is for constant use of a trickle charger if there are no keep-alive demands.
 
Brantel said:
All this real world aversion to the recommendations of the folks that are suppose to be the experts leaves me feeling unsettled about this issue. :confused:
Click to expand...

My aversion to keeping a battery on long term charge comes from 50 years of real world experience with batteries in cars, motorcycles, boats, and planes. Not to mention R/C stuff.

While it is impossible to both charge occasionally as needed a battery, and also continuously charge the same battery, and thus determine positively which works best, I have tried each with batteries of the same type/usage/manufacture etc. And in my experience, the batteries that have been on long term continuous charge do not last as long.

I have only my opinion as to why, no training or engineering degree etc. but I am suspecting that the batteries just slowly cook themselves to death if left on charge too long------even the "trickle" chargers. I used to keep a trickle charger on the battery in my standby generator so it would always be ready to start if the power went out------and every winter when I checked the generator prior to the weather turning bad, the battery was gone. Good thing I had a warranty on them. Finally after 3 or 4 years of this, the guy at the NAPA store told me to stop with the 24/7 trickle charges, and only give it an overnight trickle charge every month or so. The last battery I treated this way lasted 4 years until I sold the house.

YMMV as they say..........
 
Sam Buchanan said:
I wonder what the rationale is for constant use of a trickle charger if there are no keep-alive demands.
Click to expand...

The webinar mentions:

Sulfidation is minimized when constantly trickle charged.
Self discharge (while 3x slower on AGM) rates go up with temperature and trickle charge is suppose to prevent that
High charge currents after start if the battery is not fully charged prior to start can lead to premature failure

The Odyssey folks have some data as well in this document (pages 11-18):
http://www.odysseybattery.com/documents/US-ODY-TM-001_0411_000.pdf


All of this stuff and the user manuals for the charger and battery are what had me convinced to constantly trickle charge.

After two premature failures, I am going to switch to the real world method and see what happens. :rolleyes:
 
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Gregmarlow said:
If you can get up to KVJI, Abingdon VA, I've got one that's still got some life you can use. I just pulled it before my motorcycle crash and its on my bench in my hangar.
Click to expand...

Greg,

BatteryMart.com has my replacement on the way. I will have it on Tuesday. I can't fly this weekend so I should be OK.

Thanks very much for your offer however!
 
My bass boat has three batteries and an onboard charger, variable rates, every so often it does something different for sulfidation if left plugged in all the time. The first four years it seemed like every six months a battery went bad, would not hold a charge. I never caught it doing anything it shouldn't but came to suspect the charger. Replaced it with another and two years later have not had any more battery problem whatsoever.
 
In 1997, the battery in our one year old wave runner gave up. I ran down to the near by Battery's Plus store and had them test it. Sure enough it was toast. He suggested the Odyssey PC535? and even though it was three times the cost of the one that went bad, he said I would be happy with it and it will last for years. Well, its 2013, 16 years later and its still going strong. Never had a charger on it and even forgot to bring it in the house to keep it from freezing a winter or two. Six years ago I purchased a new ZTR mower. That battery also lasted only one year. Replace that with an Odyssey. I never remove it off season so it spends its winter in a freezing garage and again after 6 months and no charge, it works just fine every spring. I aways wonder about the hocus pocus charging theories of these batteries and wonder about its value. Maybe its different cranking over these large engine's on our planes? In any case I intend to keep mine off a charger unless it needs it.
 
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Same Bat same charger

I have the same battery and charger. Every time I think I need to trickle charge it I hook up the charger and it indicated is fully charged. Never had any indication of a weak charge after the plane was sitting for 4-5 weeks in the paint shop. I have never kept it on a maintenance charge. Most of the time I fly once a week.

It is about 6 years old and the plane has been flying for 2 1/2 years. Car batteries don't last very long in the Arizona heat, but I am impressed with the PC680 so far.

Food for thought.
 
I will only use a charger if the battery is run down, then take it off as soon as its charged.
 
My previous PC680 also had a relatively short life of 2 years. So, I emailed Enersys and asked what to do about it... and they replied to rejuvenate it, which I outlined in this post a few years ago. Worked surprisingly well.

Heinrich
 
CHECK SOLENOID

G'day Brian,

I have replaced a continuous duty solenoid supplied by Vans. The battery was showing the same symptoms as yours. Took a while to find but, with battery switch off, the solenoid was leaking small very current to earth and eventually the battery (2005) could not turn the prop despite frequent charging.

New solenoid, new Odyssey, all good so far (12 months).

Regards,
 
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My 680 is on it's 10th year. And load tests out within spec's. It never sets more than 4 weeks between flights.
Firewall mounted with full metal jacket..... No lightning holes cut.
 
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Only 3 yrs on my PC680, no problems either. I only put the Smart charger on it if I know I am going to place a drain on it while messing with the avionics while in the hangar. So not very often, but did leave the Master on for 10 days once and drained it completely. 0 volts which means a Smart charger will not charge it. I figure the 680 was toast....but I broke out my old school Sears charger(my dad was getting rid of it back in 1980), 20 minutes later there was enough voltage the Smart charger to do its business. Left it on overnight and TaDa it's alive. No problems in almost 2 yrs since.

So I'm in the no charging unless it needs it.

Disclaimer: my electrical load is very simple compared to many
 
hydroguy2 said:
Only 3 yrs on my PC680, no problems either. I only put the Smart charger on it if I know I am going to place a drain on it while messing with the avionics while in the hangar. So not very often, but did leave the Master on for 10 days once and drained it completely. 0 volts which means a Smart charger will not charge it. I figure the 680 was toast....but I broke out my old school Sears charger(my dad was getting rid of it back in 1980), 20 minutes later there was enough voltage the Smart charger to do its business. Left it on overnight and TaDa it's alive. No problems in almost 2 yrs since.

So I'm in the no charging unless it needs it.

Disclaimer: my electrical load is very simple compared to many
Click to expand...

Your experience is very close to mine. Ten days with the master on, PC680 was totally flat, I assumed it was gone for good. Battery Tender Jr. wouldn't run on it so out of desperation I left a dumb 750mA charger on it for 24 hours. Next day the battery was back and has been in service for a few years since. Amazing battery that receives no special maintenance from me.
 
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After 10 years on mine with some rather frequent bouts of inactivity, I decided to replace my 680 this annual with a new 680. Still seemed as strong as day one and passed the load test every year with flying colors. I'd put a 1 amp charger on it the first day of every month if it hadn't seen activity which I do with all my vehicle batteries getting stored for the winter. Haven't had any battery go bad for many years now- 3 cars, 1 bike, 2 airplanes.

The old 680 is now doing duty on our ignition coil test bench. I expect it will last many more years in that job.

Had nothing but great service from all my Odyssey batteries with no special chargers and maintenance.
 
yes the Odyssey is a great battery and my experience echoes what others are saying. After five trouble free years in my rocket I put a new 680 in a year ago, just because; IFR, electronic ignition etc. The new battery is NOT as good as the one it replaced. Perhaps they are not all created equal. The post about the master solenoid "leaking" got my attention. I am going to test that unit, as it may explain some of the behavior I have been seeing.
 
Still Strong

Six years flying and one or two on before that. I've only trickled it a few time while doing instrument panel work, never overnight. I'm sure if you do the next one this way it will last the same way!
 
A battery charger can actually wear out a battery I've been told. This might sound strange, but if the charger is not designed to be continuously connected to the battery it is possible. I'm not an expert on batteries, but I have worked on UPS systems with people you are. I've been told that if the charger cycles too much or if there is too large of AC component on the charging voltage then that AC component effectively charges and discharges the battery when it is connected. This continuous cycling can reduce the life of the battery. The magnitude of the AC component and the length of time connected to the charger determine the impact. A low cost charger may work fine for charging up the battery, but it may not work well too to maintain a battery. I'm not sure if this is the cause of your problem, but its not something that would immediately come to mind to most people.
 
Battery Minder???

Hey Brian,
Sorry to hear about your battery issues. I keep mine on charge constantly, more out of habit than anything. Although, from posts in this thread it is not needed.

When I was shopping around for a charger I talked to the guys at BatteryMinder and they recommended the 2012-AGM charger. My concern was being able to leave the battery on the charger for months at a time, as I am often deployed and did not want to worry about damaging my battery while I was gone. The charger can be left on indefinitely without harm to the battery. Two years now without an issue.

You may want to give them a call, as they are familiar with AGM batteries and were extremely helpful. They may have some insight on your setup.

Dan
 
Could it be?

Batteries are a black art and the same manufacturer, part number, shape, size, and weight doesn't mean they are all the same. The one you have trouble with is probably just a bad battery because of some variation in the process or the materials. I worked at a battery company for seven months where many different kinds of batteries were manufactured. Surprise, apparently identical bateries are not all equal and sometimes you are going to get a dog that slipped through quality testing installed in your airplane. RTV (return to vendor) and hope for a failure analysis (good luck with that) and buy a replacement. Based on the strong support here the next one will probably be better.

Bob Axsom
 
I had a similar experience with the PC680 and the Odyssey Ultimizer 6amp charger. Now that I know what happened I think any SLA battery would do about the same thing.

My root problem was low voltage output from the (internally regulated) alternator. I typically saw 13.8v in flight. While this should be just enough to charge the battery, it is not enough to do the absorption phase of the charge. I thought this would be mitigated by using the Ultimizer charger between flights.

Long story here but what I eventually learned is that when you connect the 6amp Ultimizer to a "charged" battery it never instigates the absorption charge sequence. It goes straight to the "float charge" mode. After two years of this the battery gets sulfated (or something) and appears to lose most of its capacity.

For me the fix was to switch to an externally regulated alternator and to set the charge voltage at 14.8v measured at the battery terminals. I no longer use a charger between flights. I was also able to rejuvenate my PC680 with the process mentioned elsewhere in this thread, and get several more useful years from that battery.

The alternator voltage you are reporting is higher that mine was, but it sure sounds like the same problem I had.

Tom Johnson
 
Bob Axsom said:
Batteries are a black art and the same manufacturer, part number, shape, size, and weight doesn't mean they are all the same. The one you have trouble with is probably just a bad battery because of some variation in the process or the materials. I worked at a battery company for seven months where many different kinds of batteries were manufactured. Surprise, apparently identical bateries are not all equal and sometimes you are going to get a dog that slipped through quality testing installed in your airplane. RTV (return to vendor) and hope for a failure analysis (good luck with that) and buy a replacement. Based on the strong support here the next one will probably be better.

Bob Axsom
Click to expand...

Bob,

You very well may be correct.
 
Got the new battery in and decided to do some testing on the charger I have.

Here is what I use:

f39fc060ada00fad613d8110.L.jpg


It is the smallest one that the Odyssey folks recommend for the PC680.

Here is a blurb from the battery manual that seems to be critical for long life. The Odyssey folks mention this many times in all of their literature so they must think it is important:

2vs3odc.png


Here is the table they are referring to:

bfhmz7.png


So 0.4 x 16 = 6.4 amps minimum...remember the recommended charger is only rated at 6 amps max.

Here is another chart they provide to let the end user know how the battery should be charged. Here we see the same requirement circled in Red for minimum charge current:

bfrfnl.png


Note: The Odyssey Ultimizer chargers are suppose to comply with these recommendations....

Last evening I fired up the panel and accessories and sucked about 25 amps out of the battery for at least 20 minutes. Obviously the new battery has good capacity and I did not drain it below 12V during this test. The old one would have not ran more than a minute before dropping to < 9v.

So now I have a new battery @ about 40% state of charge to test the charger with according to this chart from the manual:

jshg28.png


I connected the charger and started the charge cycle with a precision current meter inline and the 6 amp Ultimizer charger could only produce about 2.95 amps of current. This is less than half of the recommended minimum bulk charge current required by the owners manual of the battery. I found out later after talking to the Odyssey folks that this is normal depending on how deeply the battery was discharged.

I also found out that discharging at a high rate can lead to a false state of charge indication. They recommend that discharge test be conducted at a maximum 5 hour rate per this chart:

2invko.png


and to take it down to ~10V OCV to fully discharge the battery for testing.


Just an FYI....Not sure why but Odyssey has lowered the CCA rating of the PC680 battery. They went from 220 CCA's to 170 CCA's. Here is one of the original spec sheets:

4huweg.png


Compare this Red star with the Blue one above...the Blue star rating is what is on the new battery. The older battery (6 months old) has the Red star rating. The PHCA, HCA and MCA ratings are also lower on the new battery and literature!
 
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Excellent and informative post, Brian. The information in your post #39 should be a good reference post for future questions about the PC680 battery.
 
Measuring the amperage supplied from a battery charger "may" be a bit more complex than simply using a DC amp meter as there is usually a large AC component involved in DC battery chargers. So perhaps this is a Peak current figure rather than an average current figure which the meter is measuring.
 
I think the charger is operating properly. Was it at 14.7 volts?
The charging curve you show is for a completely discharged battery. Since yours is only about half discharged, the charger sensed this and started in the middle of the 8 hour cycle - at 3 amps, half of 6.

Nevertheless, you might ask Odyssee why they recommend a 6 amp charger when they say a minimum of 6.4 amps is needed.
 
BobTurner said:
I think the charger is operating properly. Was it at 14.7 volts?
The charging curve you show is for a completely discharged battery. Since yours is only about half discharged, the charger sensed this and started in the middle of the 8 hour cycle - at 3 amps, half of 6.

Nevertheless, you might ask Odyssee why they recommend a 6 amp charger when they say a minimum of 6.4 amps is needed.
Click to expand...

Nope,

The OCV at the start of the charge was ~12.1 volts.

Take another look at the charging curve. It is declaring the need for constant current of .4C10min which is 6.4 amps up to 4.7v. They call this the BULK CHARGE PHASE. Then the charger switches to the ABSORPTION PHASE.

The charger has LED's to tell you where it is in the cycle. I was also monitoring the battery voltage with a high quality volt meter. It was definitely in the BULK CHARGE PHASE....

I still say this charger is too small for the job or not working correctly. I am almost certain this is what killed my battery since I used the charger a bunch during my panel upgrade and during testing. The manual and technical literature warns many times to never perform the BULK CHARGE PHASE at less than .4C10min or it will damage the battery. Mine died in 6 months (with 3 of those months being panel upgrades and tests) so this seems like a good indication that something is wrong with the picture.
 
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Walt said:
Measuring the amperage supplied from a battery charger "may" be a bit more complex than simply using a DC amp meter as there is usually a large AC component involved in DC battery chargers. So perhaps this is a Peak current figure rather than an average current figure which the meter is measuring.
Click to expand...

Very true Walt. I imagine that the makers of this charger are just like the makers of cheap audio power amps. Most of them claim high power but it is in P2P instead of the real RMS rating. I imagine the same goes for this charger. However, the battery folks are clear that they must be charged with .4C10min amps and since the RMS current is what does the work, that's what we need to be seeing on the meter. I am using a true RMS meter.

I happen to have a digital O'scope I can put on the charger output to see what the true output is. It will be interesting to know for several reasons. I will post the results when I get a chance to test it.
 
Brantel said:
Very true Walt. I imagine that the makers of this charger are just like the makers of cheap audio power amps. Most of them claim high power but it is in P2P instead of the real RMS rating. I imagine the same goes for this charger. However, the battery folks are clear that they must be charged with .4C10min amps and since the RMS current is what does the work, that's what we need to be seeing on the meter. I am using a true RMS meter.

I happen to have a digital O'scope I can put on the charger output to see what the true output is. It will be interesting to know for several reasons. I will post the results when I get a chance to test it.
Click to expand...

Walt said:
Measuring the amperage supplied from a battery charger "may" be a bit more complex than simply using a DC amp meter as there is usually a large AC component involved in DC battery chargers. So perhaps this is a Peak current figure rather than an average current figure which the meter is measuring.
Click to expand...

Walt,

I measured the output of the Ultimizer charger last night with a scope while performing some more test and it has a very stable DC output. Very little AC component and what is there is at a very high frequency. I opened the charger up and it has a switching type power supply not just a big transformer and a rectifier.
 
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I have an update:

I have been in contact with the folks at the Odyssey battery headquarters. They are very helpful folks. They have instructed batterymart.com to give me credit under warranty for the 6 month old battery.

They tell me that the primary reason for an Odyssey battery to have the symptoms that my 6 month old and 3 year old battery had was sulfation.

They also gave me a special procedure to follow to desulfate the battery if it can be saved. The prodedure is to discharge the battery at the 5hr rate maximum down to ~10v LOADED. For the PC680, that is 3 amps max. And then to use the 6 amp Ultimizer to recharge the battery till it goes into trickle mode and to do this as many times as needed as long as the discharge time keeps taking longer than the last cycle.

I found my oldest battery (never threw it out) with a date code of July 09. It was replaced back in the fall of last year due to the same symptoms. I wanted to see if the special procedure could bring this thing back to life. So far I have completed 3 cycles on the battery. The first lasted about 5 minutes, the second almost 2 hours, and the third was well over 4 hours and tonight I plan to try another one. The bottom line is that this procedure seems to be working to revive this battery.

The only thing the support from Odyssey cannot explain is why these batteries are getting sulfated so quickly or at all in this application and with the continuous use of the Ultimizer charger.

I am a bunch more educated about these batteries now and I think the new one is going to last a long time even if I have to perform regular desulfating procedures on it. I still do not plan to keep it on the Ultimizer continuously.
 
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Brantel said:
The prodedure is to discharge the battery at the 5hr rate maximum down to ~10v OCV. For the PC680, that is 3 amps max.
Click to expand...

Brian - how do you do that? If it's as simple as leaving the master on overnight, I already know how. :eek:
 
larrynew said:
Brian - how do you do that? If it's as simple as leaving the master on overnight, I already know how. :eek:
Click to expand...

You need to work it out with the formula for wattage, Watts=Volts x Amps.

A load of 36 watts should do just fine----------although as the voltage drops the amperage will go up slightly. I suspect probably a 12v light bulb rated at 30--35 W should do the job.
 
larrynew said:
Brian - how do you do that? If it's as simple as leaving the master on overnight, I already know how. :eek:
Click to expand...

In the aircraft, I just turn stuff on till I get the current I want as measured by the VP-X Pro.

Out of the aircraft, I have an old car headlamp that I use for that purpose. Works great.
 
Brantel said:
In the aircraft, I just turn stuff on till I get the current I want as measured by the VP-X Pro.

Out of the aircraft, I have an old car headlamp that I use for that purpose. Works great.
Click to expand...

Sure does sound complicated....why not just fly the battery?

Do the owners of the thousands of motorcycles and watercraft that use this battery obsess over this stuff? ;)
 
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