Battery Life

[GrandpaDenny]

Hey y'all with AGM batteries, about how long do they usually last? Compared with prices paid.

[Nails]

Mine lasted less than a year.

My battery charger died and took the battery with it. I'm sure enough that I bought the same battery to replace it. And a new charger (but definitely NOT the same).

You need an AGM charger ... that works. If that influences your budget.

[Van Voyager]

Got more than 8 years out of each of the last three that AGM batteries I've bought and even when I decided to replace them, they were still working. Best bang for the buck IMHO. I'm a big fan of DEKA brand AGMs.

[sheiserman]

I've had the same AGM battery in the '89 since June 2013. It's a Super Start brand, which I believe is an OReilly's store brand and I don't know who makes them. I bought a Bikemaster brand AGM for the '97 the season before last, and of course it's fine so far. The only time I put a trickle charger on is over the winter to get the charge back to full before spring. The '97 sits more than it runs, and starts right off w/o ever having the trickle charger on it.

I've had lots of little issues downstream of the battery the last couple of years, but the battery is hanging tough.

[GrandpaDenny]

Hmph. I only got a year out of mine. But it's also a cheapie, from Batterysharks or someplace similar.

[Van Voyager]

The only time I put a trickle charger on is over the winter to get the charge back to full before spring.

I don't even bother with that. AGM batteries loose approximately 1% of there charge per month while sitting. So even after sitting for 6 months of winter winter, the battery is only down 6%.

[Nails]

I don't even bother with that. AGM batteries loose approximately 1% of there charge per month while sitting. So even after sitting for 6 months of winter winter, the battery is only down 6%.

I've also seen that statistic. But not mine, which is a reputable Deka. It was down to about 30% (as measured by my Schumacher charger) in a couple months of sitting, and probably there again now -- I'll hook it up this afternoon. Maybe leaks in the bike, maybe the cold of 7500' elevation, or maybe this stat is just wrong -- dunno.

The real problem, of course, is the "sitting" part. But with PT, my wrist might be up to it in a couple more weeks.

[Edit: yeppers, 35% since about late November, when parked at full charge. But it won't make it to freezing today.]

[Van Voyager]

My experience has been about 1% per month of self-discharge is just about right (if measured at the same temperature). Just to be clear, I'm talking about a battery sitting 'on a shelf'. If it's in a bike or car that has a current draw even when 'Off', like my Voyager does, then it's going to go drop down more than 1% per month.

[Barry]

My AGM is over 7 years old. It used to hold a charge for over 2 weeks before needing the battery tender. In addition to the constant draw from the radio, I also have a digital thermometer/clock that is continuously on. Now without the battery tender it will draw down in less than 24 hours. Even when fully charged I no longer have much available in the way of cranking AMPs. I've been running AGMs for 20 years and am taking the plunge to lithium. I will offer an option on this at the end of this year...

[cranky]

You can use a voltmeter to see the life of your battery... if it's sitting
at @11.6... you're about to be sitting too.... JM2C it was recently
proven to me... sigh...

[Nails]

Yep, mine was barely turning the engine over when it measured 30% charged. And that kind of cycling isn't good for AGM batteries.

I plan to rig a solar charger whenever I can finish this shop.

[Barry]

My battery tender only brings it up to 12.5. If I disconnect it the voltage will drop to 12.1 overnight. in 48 hours it will drop to 11.8 unless I keep the tender on it. Definitely time for a new battery.

[GrandpaDenny]

So I got a charger, hooked up Gertrude's battery to it, the charger says that the battery is fully charged (as soon as I hooked it up). Methinks this means the battery is fried. In the bike the battery was flat dead.

[Barry]

A good battery test is to first check the voltage. Then bump the starter motor which will turn on the headlight. Leave it on for 30 seconds to a minute. Then turn it off. Wait another minute & check the voltage again. If it dropped more than 1/2 volt, your battery is out of cranking amps & needs replacement.

[Nails]

I've also seen batteries develop an internal short that only shows up under a load. I mean, it seems fine until you hit the starter. I imagine this is a structural failure (plates touching each other) -- the short isn't "good enough" until there's a significant load. I think load testing is a good thing and you can do it at home: The headlights come on, but when you hit the starter everything goes black.

[GrandpaDenny]

Well the battery went dead because the trunk lid had come loose, leaving the trunk light on. It was FLAT dead. It was so dead I had to hook up the jump start battery to it for a while to bring it up above two volts so the regular charger would charge it. The battery seems to be fine, but I of course won't know for sure until I put it back in the bike and try it. With this snowstorm coming this afternoon, I'm keeping the battery indoors (on my bathroom windowsill LOL) until after the storm and the roads clear. Might be a while, more snow is predicted for next weekend too. I thought about putting the battery in and taking the bike to go do laundry as usual, but they brined the roads overnight, and there's enough salt on her that I haven't washed off yet from last week's trip to Far Northern Pennsyltucky. This is weird, I don't think I've gone a week without riding since I've owned the bike.

Not too cold to ride, but too cold to work on her.

[cranky]

... I wouldn't put that battery between someplace and a long walk home... just sayin'.....
a short has been known to "kill" a battery... and when I got my scoot, (don't ride at nite) I asked
myself how often I needed that lite... yeah, unplugged it....

[Nails]

Again, I think it's imperative to charge an AGM battery with a charger designed for them -- a decent one that has an AGM setting. Lots of folks in Webistan have killed their AGM batteries using a "regular" charger. Maybe they're super sensitive to sulfination, especially when charging from near-dead. I'm even leery of the Kawa alternator, so for any "first rides" I take the battery to 100% on the charger before starting and taking off. (I can hook up the charger through a pigtail, so don't need to fuss with the fake tank.)

[mayhem8]

I just found out a neighbor had a Voyager for quite a number of years. He said the only problem with it was that he'd go through a battery every year. I replaced mine near the end of my first season with the bike, but bought it used and have no idea how old the battery in there was. He said he thought it was a problem of overcharging, and a friend of his with the same bike had the same problem.

Are these bikes known for eating a regular sealed battery once a season? I'd have normally expected to get at least 2-3 seasons even out of a cheap battery.

[Barry]

Are these bikes known for eating a regular sealed battery once a season? I'd have normally expected to get at least 2-3 seasons even out of a cheap battery.

No. The audio system has a continuous draw. For winter storage the choice is disconnecting the battery or pull the fuses behind the headlight.