Actually, $168 / four. I know personally of some AGM's that have eight
years on 'em. LOTS more than 300 cycles. Regarding charging, I will be
using a proper 3-stage charger occasionally to top them up as needed.

The storage battery in my 'old' rig is also an AGM, 100/ah, been using
it about five years now a few times cycled far below 'recommended'
levels, by accident. I should note that the TDI alternator does supply
charge to the storage battery at 14.2-14.4 volts. My AGM experience has
been very positive, so far

Under-seat space in the 'new' rig is not possible, there is a full-width
water storage tank there. So 8-UB12220's will fill the both front
battery boxes, as the starter battery is already located in the rear.

Karl

Dennis Haynes wrote:
> Karl,
> My opinion is based upon experience and also percieved value.
>
> Yes, a deep cycle battery will last longer than an starting battery for
> this application. I can get a starting battery for $65 and my experience
> has been 1 to 2 years. So even being honest and just buying when needed
> I have a cost of $65/year.
>
> Your solution is over $200 and adds a lot of wiring conenctions.
> AGM batteries do not last as long promised. Even as promised, 150-300
> cycles is the limit.
> The 4 smaller batteies may have issues being charged across the line
> with no current control. Just not a good instalation. And with 4
> separate batteires you have 4 oppurtunities for failure.
>
> If you really need capacity, I recomend give up some space under the
> seat and get a true deep cycle battery. Note that most of the 12 volt
> RV/marine batteries still are not true deep cycles. We often call them
> hybrids. Better than SLI but still soft plate, not grid and pasted plate
> construction.
>
> AGM technology is still evolving but the price is still high for what
> they really offer unless you really need to turn it on its side.
>
> Dennis