"Short Wave Sportfishing" wrote in message
...
On Thu, 26 Feb 2004 07:01:44 -0700, "RG" wrote:


I dont' think AGM is a great technology for high use batteries.

AGM's are exactly what you want for batteries with frequent and deep
charge
cycles. You simply bought the wrong ones.

Ok, let's play a game.

Which ones should I have purchased?

Not much of a game, really. I referenced them in a prior post in this very
thread. Here it is again:
http://www.lifelinebatteries.com/marinebattery.asp.

Take the group 27 as an example. This is a very common size for deep cycles
on small boats. Lifeline's G27 has 100 AH capacity, measured at the 20 HR
rate. This is equal to the best of flooded cell batteries in its size
range, and double that of Optima's blue top. Some reasons an AGM G27 is
superior to a quality flooded cell G27.

1. No corrosive and noxious gassing when charging. AGMs were originally
designed for military applications. Lifelines still meet milspec for
non-gassing.

2. No leaking or spilling of corrosive electrolyte.

3. All batteries have a finite life. AGMs have been shown to have
significantly more charge cycles in their life than flooded cells, and this
is comparing them to properly maintained flooded cells. Neglect or abuse a
flooded cell, and it's not even a horse race.

4. AGMs are substantially better equipped than flooded cells to deal with
shock and vibration, common environmental conditions found in a marine
application.

5. Efficiency. Due to their relatively high internal resistance, three
performance advantages are achieved over flooded cells. A) They will
retain their voltage better under heavy current load. B) They will accept
recharging current much faster than a flooded cell, resulting in shorter
recycle times. C) They have a negligible self-discharge rate, much lower
than flooded cells. This is important if your batteries tend to stay idle
for long periods of time.

6. All of the above comes with the sweetest bonus of all. Zero
maintenance. Big in my book. Please note that the above characteristics
may not necessarily apply to gel-cell batteries, which are a completely
different, and much inferior technology to AGM technology.

Lifeline G27's can be bought for about $150-160 each. 5 year warranty.
I've had three of them in service for two and a half years. I've more than
gotten my money out of them, but they still are going strong. These are
house/starting batteries that are very heavily used. If they died tomorrow,
I wouldn't hesitate to replace them with the very same battery, even if the
warranty wasn't in place.

Batteries are no game to me. I researched long and hard before laying out
nearly $500 for three of them. It turned out to be one of the very best
$500 I've ever spent on the boat. These inspire complete confidence and I
no longer have to contort myself monthly to perform maintenance on batteries
that are difficult to access. If I'd known then what I know now, I would
have removed the OEM flooded cell G27's immediately upon delivery of the
boat and donated them to someone at the marina, replacing them with the
Lifelines. Would have made the first two years of ownership much more
enjoyable.

BTW, Lifeline AGMs are standard equipment on many U.S. Navy crafts, fine
yachts built by Pacific Seacraft, Island Packet, and Hinckley Company to
mention three, and quality coaches built by such companies as Vision Coach,
Royal Coach and Vantare Coach.