Not speaking to your situation, but here are some factors.


Flooded These "regular" batteries have a
liquid of sulfuric acid between the plates. When charging they produce
hydrogen and oxygen so they must be ventilated and periodically topped off
with distilled water. The "maintenance free" models do not need water (not
recommended for hot climates).

+ Lower initial cost
- Acid spill if battery is cracked or tipped. Must install upright.

+ Accepts higher charging voltages (less likely to damage)
- Requires periodic maintenance

+ Less damage when overcharged
- More fragile in high vibration environments


- Discharge rate of 6% to 7% per month


- Requires periodic charging when not using





Gel Instead of water, a gel of
sulfuric acid, silica, water, and phosphoric acid is used between the
plates. This gel is very viscous and doesn't leak out of the battery.

+ Won't spill if cracked / can install on it's side.
+ No gasses / no venting / less chance of explosion.

+ Resistant to damage caused by shock or vibration
+ Can be shipped via UPS

+ Last longer in real boating conditions.
- Higher initial cost.

+ Discharges at only 3% per month (at 68°F)
- Should be charged at under 14.2 volts or will be damaged.





Absorbent Glass Mat (AGM) A dense glass mat that is saturated with
acid electrolyte is used between the cells. There is nothing to leak out
should the battery be cracked or broken.

+ Very low internal impedance = high starting power
+ Submersible without damage

+ Will not spill if cracked / can install on it's side
+ Maintains higher voltage when discharged

+ Dual Purpose: Good for starting or deep-cycle
+ Can be shipped via UPS

+ Very resistant to shock & Vibration
- High initial cost.

+ Discharges at only 3% per month (at 77°F)
- More weigh per Amp Hour