Battery replacement needed?

[BBB]

Got the zx6r battery on the optimate and it's pulling the full 0.8A for the last couple of days with no testing or cycling.

Off the charger voltage quickly drops to 10.5v, safe to assume a cell has expired?

[Skub]

Sounds like it's duffed. Anything less than 12.5v won't be interested in a cranking job.

[wull]

The 10.5 shows that a cell is more than likely goosed, 6 cells at roughly 2.1v each gives you the 12.6v which it’s meant to be fully charged.

If the battery was sound it wouldn’t drop so much that quickly.

Replace it.

[Rockburner]

it's fooked.

[1913]

With the old lead acid, you could dip voltage tester prong into each cell and confirm a dead cell.

The 2 volt deficit is a give away though, it's entirely Boris'd.

[BBB]

New agm battery from tayna arrived today showing a healthy 13v after a run on the optimate and a couple of hours to settle.

Old battery only shows 7.5v now, looks like another cell had gone.

[wull]

Nice easy fix.

With the new battery fitted check the charge rate whilst it’s running, just so you know the charge system is working as it should.