Skyview Backup Battery Charging

I edited this post after asking questions on the Dynon blog. I was concerned about damaging my Odyssey PC680 AGM battery with a "dumb" car battery charger. Dynon posted:

It is not an abuse of a lead acid battery, including AGM, to charge it at 14.7V or float it at 13.6V forever. You can actually keep an AGM battery at 13.6V with a power supply all day with no harm.

Your alternator is not a sophisticated charger and your battery will be subjected to that every flight...

Read the Odyssey manual here (page 12):
http://www.odysseybatteries.com/files/techbook.pdf

They also wrote that the backup battery does trickle charge when below 12.25v but extremely slowly. So slowly that it would take weeks to recharge but only an hour or two when above 12.25v. I was also concerned about this quote from the Skyview installation manual:

To conserve your aircraft battery, the SV-BAT-320 is only charged with [sic] SkyView detects your alternator/generator to be online.
 

Turns out that hooking an old 10v car charger to the main battery worked just fine and with Skyview on and the backup battery hooked up, it took about two hours to get the Skyview backup battery up to full charge.

Here's the trickle charger I'm using. Schumacher bought at Walmart for about $18. I leave this running all the time.

It has a pigtail with a quick disconnect that I leave attached to the battery.