Like all batteries, the Optima has a set of trade-offs. For starters, their spiral-wound, cylindrical design, which hails from the very first commercial AGM battery
design, makes them highly vibration and drop resistant as well as very slightly
more efficient when accepting a charge.
The downside of the cylindrical design for us RV owners, on the other hand, are many. Their cylindrical design leaves lots of unused space between the cylinders that square cell battery
designs use to for additional capacity. A spiral-cell AGM battery's capacity is about a third, 50Ah (Amp-hours) capacity, compared to a box-shape design that packs 75-80Ah into the same footprint.
Flipping back to advantages for a moment, AGM batteries weigh slightly less per Ah than traditional flooded cells do, and the the amount of weight
per Ah is pretty comparable between Optima and other AGM batteries. So, if you are trying to save weight
and all you need is a 50Ah battery
, the Optima might be your best bet.
Another difference is Optima brand doesn't make a pure deep-cycle design. All their "RV/Marine" designs are hybrids that can be used as a marine starter battery and deep cycle.
Finally, there's the name. The Optima name tag seems to boost prices by a third or so per Ah.
Another difference -- I won't call it an advantage or disadvantage -- is that Optima has been using the same basic battery design for 25 years, and a few of those Optimas are still in serviceable condition. With a desulphination float charger you can expect to get 10 or more years out of a quality AGM battery, Optima or otherwise, as long as you don't bust its charge down to flat nothing every year or overcharge it frequently.
Overcharging is, however, a great way to kill an AGM battery. Unlike other designs, there's not a lot of electrolyte (aka water) in an AGM battery, so it's easy to "boil" the water off into oxygen
and hydrogen gas by overcharging them. To compensate for this, AGMs have a reaction chamber that re-combines any hydrogen and oxygen
that boil off back into water, but it's a slow process that can't keep up if you overcharge the battery often.
I have an Optima in my Scamp
5er. It's been a good performer, but I've learned that the Scamp's converter has a tendency to overcharge batteries and is not good for my battery life. So, most of the time, I don't even turn it on and depend on either on our tow vehicle or solar
cells to charge the battery when we're out on the road. When the trailer is in storage I use a small, smart desulphination trickle charger (a BatteryMinder) to maintain my battery.
Longer term, I'm thinking of removing the converter all together and replacing it with a smart 6 or 10 amp charger with a desulphination feature, and will do exactly that with the Surfside
project trailer we're working on. (Our Surfside
is currently hollowed out and sitting in our garage, devoid of windows
, doors, cabinetry, or appliances and detached from its frame. It does have a new floor . . . )