I've got them and they are no better than a good numax
Battery that's a third AC the price , ESP just is you're using
To start van or run a pump off. The optimas were designed
For super harsh conditions and can be mounted upside down
But if you run them completely flatten you will kill the battery.
There are also a few bad batches out there, my advice would be to buy
Two 85-100amp numax or similar over one optima.