Exactly what I found, couldn't even use the GS-911 because the battery would never be high enough for it to workMotobatt for me too - put on the Yuasa 16ah around 4 years ago, replaced a couple of weeks ago due to slow cranking. It never showed more than 12.7v off-charge. The new Motobatt hybrid is currently showing 13.4 after not being used since last Thursday, despite the bike having a tracker.
Since going over to the Motobatt absolutely no issues.