How many of you guys use batteries that are not lead-acid?

My bike goes through lead-acid batteries pretty fast. Two years seems to be about the most I get out of them, so I'd like my next battery to be one that will last longer. AGM batteries are lighter and maintenance-free (right?). And there are lithium batteries, too, which are lighter still. You guys have any experience with them? Worth the extra cost? Live up to their billing?

The Shorai lithium batter for the Monster costs about twice as much as a lead-acid Yuasa battery and weighs a mere one fifth as much!

Have used Lithium and AGM, both are worlds better. I have a AGM now that has been totally problem free and abused on several occasions without issue. AGM can be had cheap and last well. The Lithium had some temperature sensitivities and were not as strong. No probs at all with AGM.

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The biggest item for me that has affected battery life has been to keep them on a trickle charger whenever the bike sits for more than 24 hours.

I've had batteries last for 5+ years when cared for in this fashion.

I've not used AGMs but have heard that they're more forgiving and long lived than traditional lead acid batteries by most accounts.

I had no problems getting 3-5 years out of AGM batteries while treating them like dirt (no trickle charges, exposure to high heat and freezing cold, drawn down to nothing and charged back up, etc). Lithium batteries can be abused further asnd don't require trickle charges to hold their voltage, they can be left for up to a year. BUT, they are much more sensitive to temperature and start falling in performance considerably below 32F.

Taking the bike out for a long ride should help, say to College Park?

That's an excellent idea! With winter coming, I'll have to do the "U" route - Victoria to LA, east to Atlanta, then north. The battery should be good and charged by then.

I have a Battery Tender, which I have used both religiously (battery died) and sparingly (battery died). Eventually the battery loses its water, after which point it doesn't last long. On the bright side, I've never been stranded and I get warnings that it is gradually failing. [still talking about lead/acid batteries here] Even when Yermo and I were in Idaho and the thing went completely dry and got scorching hot, we added distilled water, rode another hour and a half or so, overnighted, then rode around in the morning till we got to the right shop to replace it.

Does an AGM battery fail gracefully like that, or do they suddenly croak?

Maybe it has something to do with the charging system on my bike. I replaced the voltage regulator/rectifier three years ago, just as a precaution, but that hasn't changed the battery situation.

A voltage meter would be a good addition to my bike...

The last time I replaced an AGM it had a slow demise, only noticed by starting to be slower cranking. this was a battery that had been drained to death twice (not important why lol), and then recharged brutally with a high amperage charger. This battery had also been never hooked up to a trickle charger and went weeks in freezing temps. After one particularly hard winter I had to charge it up a bit before it cranked the motor, then didn't touch it again until selling the bike. It was a higher end AGM, but still well under $100

Sounds good. I'll make the next battery an AGM.

Thanks for the input.

Lithium are great if freezing isn't an issue, but the cost differential is still too high for me. A great AGM battery can be had for half of the cost of a Lithium...and the Lithium aren't really twice as good. AGM are worlds better than traditional though and not much more expensive. Made it easy economics for me.

Ian, an AGM certainly wouldn't be a bad choice. As for the battery symptoms you describe, it sounds like your battery tender may have had an issue.

They're supposed to to move to a "float" charge of about 300 milliamps once the battery reaches a full charge at the normal rate, which really shouldn't dry a battery out in the manner you've described.

Perhaps it might be worth trying a "battery buddy" instead next time? I've not looked at reviews for a while--MCN might have done fairly recent tests of some different battery maintainers.

It certainly could be the Battery Tender. After the last time I replaced the battery I decided to use it more sparingly and never leave it connected for long periods of time. For example, over the winter when I wasn't riding I'd connect the BT once every few weeks, let the battery go to full charge and then disconnect it.

But my current battery suffered the same fate, which could indicate that it's the BIKE that is causing the batteries to dry out prematurely.

Since I'll be storing the bike for the winter soon, I'll get a new AGM battery in March and a new charger to go along with it. I'll try to remember to report back in a few years when all is still well! [fingers crossed]

Have you measured the voltage when the bike is running?

No. At least, not recently enough that I remember what the readings were like.

Measure at the battery terminals?

FWIW, the reason I replaced the voltage regulator/rectifier was because I had heard reports of the stock units spontaneously failing, not because of any problems I had experienced.

My last car experienced a charging system failure where it was charging at 17+ volts. Needless to say that caused much havoc.

Yea, it's worth doing a quick check to see what the voltage is at the battery terminals. As you mentioned, it's probably a good idea to add a volt gauge somewhere to keep an eye on it.

Interestingly my Honda Blackbird had a terrible habit of toasting its rectifier. It was a well known, documented, and easily remedied problem though. In that case the best solution was to instal the rectifier from a Yamaha R1, fit and worked perfectly. The rectifier though also had a very easy to diagnose way of failing. It went *poof* and with the fine smell of burnt electronics you were dead in the water :-). Until the R1 mod I actually kept a spare with me when I rode. It was the only blemish on what was otherwise a mechanical device with the reliability of a hammer.

Well, waddaya know. About 15v at idle and up to 18v at 4,000 RPM.

Looks like I've got some homework to do.

Came across this charging system fault diagnosis chart. Thought I'd share the link.

Ouch. I suspect 18V is very bad for the battery.

Essentially, at 18v, you're going to start "boiling" the battery, drying it out and shortening it's life a great deal. Batteries should be getting about 14v max when charging.