New AGM won't hold charge from Battery Tender

[jknappsax]

I bought a new Yuasa YTX14AHL-BS AGM battery a month ago, and have a Battery Tender Plus which I've used a number of times on my old Parts Unlimited flooded-cell battery with perfect results. I've been setting valve clearances and cleaning/rebuilding the carbs on my 1979 GS 1000, so I hadn't installed the battey. About a week ago, I put the acid in it and put it on charge overnight. The charger showed it as charged the next morning. I snapped the permanent-sealing caps on it, and put it on to trickle. Sunday, I wanted to do a quick cold -compression test, as before the valve adjust the compression was marginal in all cylinders during a cold-compression check. I installed the battery, hooked up the compression tester to cylinder #1 and no plugs in any cylinder. I hit the starter, and it cranked over very slowly a time or two, then wouldn't any more. I unhooked the battery cables and did an open-circuit voltage reading on the battery, and it read 11.4 Vdc. I put it back on charge, and when the charger showed green, I read the battery and got 12.0 Vdc, so I reinstalled the battery, same thing. I checked with Deltran, and they said that the Battery Tender Plus should have no problem charging and maintaining the battery. Any thoughts on what might be happening here. The bike started great before I pulled the carbs to solve a mixture problem, and that was with a 5-year-old flooded-cell battery.

[Dave8338]

I've had the same problem with one (battery) that I got from Wall Mart and thought it was just a bunk hunk-o-junk. Took it back to them and got my money back. My guess is that you just picked up a bad battery.

[jknappsax]

I've got another on its way from Bikebandit.

[bakalorz]

I bought a new Yuasa YTX14AHL-BS AGM battery a month ago, and have a Battery Tender Plus which I've used a number of times on my old Parts Unlimited flooded-cell battery with perfect results. I've been setting valve clearances and cleaning/rebuilding the carbs on my 1979 GS 1000, so I hadn't installed the battey. About a week ago, I put the acid in it and put it on charge overnight.
<snip>

The above caught my eye. As far as I know, AGM batteries have the electrolyte installed when you buy them.

Bike bandit describes the battery as maintenance free, not AGM.

[BassCliff]

Cooking with electrons

Hi Mr. jknappsax,

Sorry to hear of your troubles. I have the same battery, bought from a local bike shop. It seems yours is defective or it wasn't initialized properly.

From http://www.yuasabatteries.com/batteries.asp

Maintenance Free

Absorbed Glass Mat (AGM) Technology is an advanced battery design used in Yuasa's Maintenance Free Batteries that eliminates water loss. Once it's filled with acid the battery is permanently sealed - so you'll never need to fill it with water or check the acid level.


Long Life
Because of its lead calcium design, the AGM battery will hold its specific gravity more than three times longer than conventional lead antimony types. This means much longer periods between charges when the battery is used in a standby mode, like winter storage.

And to remain factory-fresh the AGM battery is shipped dry along with its own pack of high-gravity acid that's added at the time of installation.

Sealed, Non-spillable
Once filled with acid from its special packs, the AGM battery is virtually maintenance free. It's totally sealed and all of the acid is absorbed in the special plates and separators, so there is no need to worry about acid leaks on valuable vehicle parts and accessories.
**************

Mine's been working great for a few months now, knock on wood. ](*,)

Thank you for your indulgence,

BassCliff

[jknappsax]

Well, Cliff, in reading all this, I'm still not sure if the battery was initialized properly. I precisely followed Yuasa's instructions, and checked with Deltran that their Battery Tender Plus would properly charge an AGM battery. Yuasa's instructions just said to put in the acid, let it sit for about 30 minutes, then leave the sealing caps loose until the battery has been charging overnight, then to snap them tight and leave them sealed. I know that an AGM should be charges at 14.4 to 14.8 Vdc, but I did not check that was the charger output. As far as anything I could find, the Battery Tender Plus is smart enough to know how how to charge an AGM, and doesn't have a VR adjust to set. Any concrete recommendations?

[focus frenzy]

do you have anybody nearby that might have a low output battery charger you could borrow?

doesn't the battery tender plus have a flash patter to the light to indicate a bad battery?

[jknappsax]

Bakalorz, my Philly bro, the YTX14BS-AHL is definitely an AGM battery. The glass mat is what absorbs the acid, thus AGM. Check Yuasa's website. They ship without the acid so that you activate it shortly before you want to install it. That way you don't get batteries that have been sitting on the shelf and going bad without being trickled. The acid, which isn't sulfuric, comes in this really cool strip of six plastic bottles in a strip, and you place it in the tops of the cells, and it breaks the seal and fills the cells.
Cliff, after getting a callback from Yuasa tech support, he said that indeed, the battery had not been initialized properly. The procedure with a smart charger is to charge it overnight, then take it off charge and let it cool for an hour or two, and repeat this probably two times. He said that the battery being warm fools the charger into thinking the battery is fully charged, and then it will only output 13.4 Vdc roughly, which is the float voltage , so it won't fully charge the battery. It's not until it HAS taken a full charge that the smart charger, in this case a Battery Tender Plus, can properly charge and maintain the AGM. It's odd that Yuasa's instructions don't discuss this at all, yet it is a necessary step in prepping your battery. My battery is on charge overnight now, and I will try it again tomorrow as well.
Leon, the Battery Tender Plus does have a flash mode to indicate a bad battery, but it is being fooled into thinking the battery IS charged.

[BassCliff]

Hi Mr. jknappsax,

That's good information. Thanks for sharing. I hope your battery lives up to it's "potential"! :-D:-D:-D ( I just slay me! )


Thank you for your indulgence,

BassCliff

[1980GS1000E]

I fall into this category of not initializing the AGM battery properly, too, but I haven't had any problems. Should I charge the battery on a charger, not the tender?