I didn't find anything searching, doesn't mean its not there, just I cant search well. I've tried harley forum, but thats all double talk. (talking out their rear)
My agm battery is less then 4 yrs old, sits on the maintainer when I'm not riding.
Harley meter said 12 volts, barely cranked, but it did start. Moved it out of garage for spring wax. hooked up maintainer, Maintainer said battery at 9%.
9%, ouch. Time for a new one I assume. Whats lifetime for agm? I've done better with plain lead acid units in past, without a maintainer over winter.
Maintainer spits out 14.x volts, harley charging spits out 14.x also. Battery spits out 12.x after removing maintainer.
Do I just have bad battery, or bad charging?
Upgrade to lithium or go back to lead acid?

 

I do not know all the ins and outs, but they do say you need a certain charger for a certain type battery. Some chargers let you program what battery you are using.

 

My charger has different settings for AGM and non-AGM batteries.

I just put AGM batteries in my trucks last year, so I hope they last longer than 4 years. They definitely have much stronger starting power than regular ones.

 

I'm guessing this is a motorcycle battery? If you get 5 years out of one, that's pretty good.

 

AGM batteries don't like and don't need to be float charged. Especially at a high voltage as the gel will crystallize. What charger are you using? Also what brand of AGM? The only AGM's worth anything are Northstar or Odyssey.

 

will dig under seat and find what battery this week.

 

AGM batteries also should be charged at a minimum of 25% of their 20 hr amp hour rating.

Assuming this is a battery for a motorcycle, rather than for a Ford truck, the amp hour rating will be a lot smaller than a typical light truck battery... but still larger than the charging current developed by a battery maintainer.

The 20 hr amp hour rating for my Ford truck batteries is 74ah. 25% of 74 is 18.5, which means I need to charge my AGM batteries with a charger capable of producing 19 amps of charging current. So I bought a 25 amp smart charger.

Let's say a large motorcycle battery has a 20 hr amp hour rating of 28ah. 25% of 28 is 7, which means one would need to charge that 28ah AGM battery with a charger capable of producing at least 7 amps of charging current. A 10 amp charger would fit.

A 2 amp "maintainer" type trickle charger, however, would not fit the needs of charging AGM batteries, which call for higher current charging, even while simultaneously calling for tighter constrictions on the charging voltage.

 

hmmmmm, battery has reached the stage, where running lights engine off, looking for bad running light connection, takes battery to 9.5 volts (wont start harley) in 20 minutes. There goes another Hundred Dollars.
But it sounds safe to hook up to 2 amp/10 amp charger in the future
Baterry maintaner pssssst.

 

My experience is you'll be fine with your maintainer. I've got several agm's sitting on a Battery Tender branded 10 lead maintainer. Most of the time, with a decent battery, I get 7-8 years out of a battery. If I go cheap, I get 4-5 years out of one. All agm's. I've just bought my first supposedly high quality non oem branded agm and installed it last week. It definitely started the bike much better than the supposed "high powered" one it replaced this past weekend when I took the bike out with the new battery. The old "high powered battery made it 4.5 years and left me sitting after being ridden for 35 miles. I do find there's little to no warning an agm is failing. It just won't start the bike one time. I've also got 6 large agm's (8 D size) that sit on a large tender the vast majority of the time, that are almost 11 years old. They were installed in June 2008 and still doing fine, though I'm thinking about pulling them to load test them in the near future.

 

Bike has been sitting 24hrs now, kill switch engaged , no maintainer, battery 5 yr old original. I bought it last year. I'm gonna let it sit 4 or 5 days. If it doesn"t start I'll toss battery

 

Got one bought. There is a Batteries+ store an hour from me and they had three in stock so I ran over and got one, cost $374.45 with tax. They had one of the X2 Batteries left but I wanted the Odyssey.

 

My Harley came with a little charger. It was labeled as a Harley part. It's actually a Battery Tender, labeled for Harley. I have a NOCO charger which works much better.

The cheapest battery that I could find for my Harley was an ACDelco. $40. AGM. So far, it has worked for years. Ride the bike. Put it on the charger if I don't ride it for awhile.

On my truck, I am using Optima. I had a Yellow Top for about 6 years. Then I didn't drive the truck for the winter. The battery died from not driving, and being in the cold during the winter. I tried to recover it with my charger. The charger says that it repairs stratification and sulfation. But the best charger can't do anything, if the battery is damaged beyond repair.

I find that with battery chargers, you can spend as much on a charger as you spend on the battery. The chargers that are expensive, are probably better than the cheap ones. But the best use of a charger is as a maintainer. You have to use the charger before the battery dies. That means plugging it in regularly, to charge and top off the battery. By the time the battery has dropped so far in voltage that it can't start your car, then the battery is probably so old and damaged that it can't be repaired. And batteries have a finite life. You can't keep it running forever. No matter which charger you have. If a battery is just old, it's old. You can expect the battery to outlast the warranty if you take care of it. Battery warranties can be 1, 2, or 3 years. Maybe you can get 5, 6, or 7 years out of it. But don't expect a battery to last forever.

 

Probably both.

Bad charging, over 4 years, created a bad battery.

Enersys, the maker of Odyssey, Northstar, X2Power, Hawker, the original Sears DieHard Platinum (2007-2015), and other private labeled thin plate pure lead AGM batteries... states that plug in the wall battery maintainers (trickle chargers) should be regulated to no less than 13.5 volts, and no more than 13.8 volts.

You said your maintainer was "14.x volts."

Enersys says 14 volts is within range (minimum) for alternators on vehicles, but not for battery maintainers off vehicles.

Here is the exact wording, from their warranty statement:

"Overcharging, undercharging, charging or installing in reverse polarity, improper maintenance, allowing the Battery to be deeply discharged via a parasitic load or mishandling of the Battery such as but not limited to using the terminals for lifting or carrying the Battery. Trickle chargers that do not have a regulated trickle charge voltage between 13.5V and 13.8V (no lower than 13.5V and no higher than 13.8V) will cause early failure of the Battery. Use of such chargers with the Battery will also void the Battery’s warranty. For applications where an alternator is present, the alternator must deliver between 14.0V and 14.7V when measured at the Battery’s terminals. Consult the ODYSSEY battery technical manual or owner’s manual for any necessary temperature compensation. Alternators that do not have a regulated charge between 14.0V and 14.7V (no lower than 14.0V and no higher than 14.7V) will cause early failure of the Battery. Use of such alternators with the Battery will also void the Battery’s warranty."

As can be seen, Enersys is more exacting about charging voltage, down to the voltage tenths.

You described your charging voltages both off vehicle (trickle) and on vehicle (Harley) as "14.x", where the value for ".x" was disregarded.

That value of the tenths in charging, and determining state of charge, is really important in low voltage batteries. If your Harley alternator is putting out 14.8 or 14.9 volts, then the Harley is also overcharging your AGM battery.

You've already established that your trickle charger, at "14.x volts", is "maintaining" the AGM at least 4 tenths of a volt higher than Odyssey's limit for trickle charging AGMs. And if ".x" is actually .4, then the overcharging voltage is 8 tenths.

AGM's have virtues that are worth paying closer attention to the details of charging... the main benefit being no spillage of acid from vibration that etches into the paint and chrome finishes of the mechanical work of art that Harley's are symbolic of.

There is also no need for dealing with opening battery caps and checking water levels or measuring the specific gravity of each cell.

A high quality, self regulating, smart charger makes a good companion for enjoying the maintenance and mess free virtues of AGM batteries.

 

Sometimes, you have to buy a better charger. And those are expensive.

I am using a NOCO genius 10. The only problem is that Harley installed an SAE style connector, and NOCO uses a proprietary connector.

I don't care what they claim. I have yet to see a deeply discharged battery with stratification, sulfation, and damaged cells get fixed by a charger. I've tried it. Perfectly good batteries that still start your car or bike? Sure. Put those on the charger. It will give you a full charge. But a battery which is damaged? A battery that won't start? Put those on the charger, and the battery gets hot, the charger gets hot, you hear bubbling, boiling, and cracking - that battery isn't getting fixed. You can't put it on the charger, and get a new battery at the end of the charge cycle. I've seen old batteries get recharged. Install them back on the car or bike, and it fires right up. Why not? It just came off the charger. But it won't hold a charge. Overnight, the next day, you go to test it with a multimeter, and the voltage has dropped again.

When I think about it: if the car or bike is starting, how many people are checking the battery with a meter or load tester? It's when the car is not starting. Then you get a diagnoses. Is the alternator bad? Is the battery bad? Are both bad? On a 12 volt system, you operate around 14 volts with the car running. When the car is off, that battery should hold above 12 volts. When it drops, you can't start the car. In some cases, the battery warranty is expired. It's just time to get a new battery. Is it worth it to spend up to $200 to buy a charger, to fix a battery worth less than $200?

 

I am not sure about any of the chargers you buy now. All these "smart chargers" will not charge a battery if the voltage is too low. I always keep a old timey charger around to bring a really dead battery up initially. Then the regular "smart charger" will take over and work.

Golf cart chargers are bad for this. If you have several people using one cart, and no one maintains the charge, it will die and cannot be charged. On some of the chargers I will hook it up to the cart, and then take another old timey charger and hook it at the same time to the battery bank. That will bring the voltage on the pack up enough to where the regular smart charger will start working and bring the charge up.

Had a call to a old couple I know, they had disconnected their stairway chair lift for a couple of months, and then plugged it back in and wanted to use it. It kept having a battery error and would not work, the charger that came with the system would not charge the battery. I took the battery out, brought it home and put it on my old timey charger and left it on there for a few hours. This was one of those small lead acid batteries like is in kiddie cars. Checked the voltage, it was up. Took it back and installed it, and that battery is still working years later.