Battery Desulfator

[mojoman]

I picked up a couple of Battery Desulfinators on sale on amazon:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Installing one on my aux AGM battery. Has anyone used these before?
I've brought batteries back with a smart charger with this feature but never had one installed running full time. thinking of putting the other one on the engine battery.

[mojoman]

For those who care, I used one on an old battery, three days of trickle charge with Desulfator brought a battery up from maintaining 12.4v to 12.8v.