Hi, I have a problem with AGM battery 12 v/35 ah, 2 years old. From time to time in the morning usualy it wont start the engine. Its spinning too slowly. But always start on bump start and fill the battery regularly.
What is confusing is voltage which is 12,9 volts or even 13 all the time. On idle with headlights on voltage is more than 13 volts. Voltage regulator brand new.
Anybody with similar experience with AGM battery?

It won't be the battery. Probably the battery connectors or starter brushes.

Probably starter brushes, do the headlight and or indicators act funky. If they do it is one of the signs of dirty starter brushes.
Regards Martin.

Headlight, indicators, all electrics function normally. I ll try to clean the starter.
Thanks

Clean all your ground connections as well.

Yes. Ground connection for sure. Probably the most important one for the starter is the bed where it bolts down to the gearbox with 2 bolts. It can get corroded under there and this is required by the starter for earthing.

It was most stupid reason - loose minus pole on battery. Thanks all

The best possible fix!  One that doesn't require any expense beyond a little time.

Am I to understand that I can lay my AGM battery on it's side? This is a big deal as it will positively impact my battery relocation.

Vitamin K wrote:Am I to understand that I can lay my AGM battery on it's side?

That remains to be seen.
http://www.yuasabatteries.com/faqs.php?action=1&id=27

If you are constrained for a battery mounting location you might want to use a lithium battery.  They offer a large capacity in a small, light package that can be mounted in any orientation.

If this is a cafe conversion you need it for, I would guess that it would be fairly easy to recoup the additional cost for the lithium based on it's cool factor.

The answer is yes, and AGM or gel battery, as they are also known, can be used on its side.

It even states so on the paperwork that comes with the battery. The only no-no is to mount it upside-down - but why would you want to do that!

Dai wrote:It even states so on the paperwork that comes with the battery. The only no-no is to mount it upside-down - but why would you want to do that!

Thanks all. This AGM I have is considerably smalller than a standard battery. If I lay it on it's side I can put it in the seat cowl, but I want to keep that space clear for my tool roll and tire plugs, so I going to lay it sideways in the current battery tray and make a clean black box to cover it.