BoatBanter.com - Gel cell batteries

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Gel cell batteries - why?

Curiosity: Why would I consider buying a gel cell battery? My current
battery is used for running lights, fish finder, and occasional shock
"therapy" when my son is making too much noise and scaring the fish away. A
trolling motor will arrive soon. I don't use the battery for starting the
motor.

Gel cell batteries - why?

"Doug Kanter" wrote in message
...
Curiosity: Why would I consider buying a gel cell battery? My current
battery is used for running lights, fish finder, and occasional shock
"therapy" when my son is making too much noise and scaring the fish away.
A
trolling motor will arrive soon. I don't use the battery for starting the
motor.

Gel battery advantages:
1) Can't spill. Can even be mounted on its side.
2) Never needs to have water added, allowing you to put it in hard to get
to spots.
3) Is more efficient during the charge cycle.
4) overall life expectancy is usually longer

Gel Battery Disadvantages:
a) costs more
b) for a given size, has a lower amp-hour rating/.
c) has a different "full charge" voltage, making them incompatible with
regular lead acid.

For your application, advantages 1 and 2 are probably signficant, and
disadvantages a and c.

The spill factor is obvious, and can be really important if the battery is
exposed or moved around a lot. Being able to tuck it up in some "it takes
all day to get to" spot is reasonable if you never have to get at it again
for the next 5 years. The cost factor is another obvious one. The final
charge voltage is something that you should consider. Gel cells want to be
topped off with a final charge voltage that is a little lower than a regular
lead acid. If you wanted to hook this up to your boat's alternator and
charge while the engine was running you could end up overcharging the gel
battery and damaging it. You certainly wouldn't want to have a gel and a
regular lead acid connected via the battery switch.

The efficiency during the charge cycle is really only important to those
people who live day after day on a limited amount of charging time. Ocean
going sailors are one example, where they need to recharge their batteries
via the solar cells each day. A small improvement in charging efficiency
can make the difference between getting enough out of the solar cells and
having to run the engine. For a weekend user, you just put the battery on
the charger and let it charge all night, who cares if it took 10 hours
instead of 9?

The amp-hour capacity of the battery could be an issue if are already deep
cycling your battery. The large "marine" style battery (size 27) is
typically around 100 amp-hours in lead acid and only ~80 in gel. If you
need more than 80 amp-hours you will find your gel battery going dead while
the lead acid would have still been okay.

Rod McInnis

Gel cell batteries - why?

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

Gel cell batteries - why?

"Gary Warner" wrote in message
...

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).

Hmm. Mine is maintenance free, which I chose because for the time being,
there's absolutely no place to fasten it down in my 14' boat. It sits wedged
(fairly) securely between the transom and a plastic milk carton which holds
some fishing stuff. But, that means it's in the sun constantly. Perhaps I
made the right choice, in terms of heat.

- Discharge rate of 6% to 7% per month

Mine comes off the charger at about 12.8 volts (confirmed with two different
digital meters). After a week of use, it drops to about 12.3 and sits there
for a month or so before dipping to 12. It's been the same since day one.

Gel cell batteries - why?

"Doug Kanter" wrote in message
...
"Gary Warner" wrote in message
...

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).

Hmm. Mine is maintenance free, which I chose because for the time being,
there's absolutely no place to fasten it down in my 14' boat. It sits
wedged
(fairly) securely between the transom and a plastic milk carton which
holds
some fishing stuff. But, that means it's in the sun constantly. Perhaps I
made the right choice, in terms of heat.

- Discharge rate of 6% to 7% per month

Mine comes off the charger at about 12.8 volts (confirmed with two
different
digital meters). After a week of use, it drops to about 12.3 and sits
there
for a month or so before dipping to 12. It's been the same since day one.

Well, it sounds like you've already made up your mind. But ask anyone who
has owned AGM's and they will tell you that they will never again buy
another flooded cell battery. They're that good. Gel cells are yesterday's
news. There is absolutely no reason to buy a gel cell. Either step up to
AGM technology, or if not convinced, stay with your flooded cells.

Gel cell batteries - why?

"RG" wrote in message news:TOKcb.5288$Rd4.1938@fed1read07...

Well, it sounds like you've already made up your mind. But ask anyone who
has owned AGM's and they will tell you that they will never again buy
another flooded cell battery. They're that good. Gel cells are
yesterday's
news. There is absolutely no reason to buy a gel cell. Either step up to
AGM technology, or if not convinced, stay with your flooded cells.

No...mind's not made up. When I bought my present battery, I wasn't aware of
AGM versions.

Gel cell batteries - why?

Thank you! Yet ANOTHER place to spend my money. But, isn't that what boats
are for? My girlfriend has found some elegant porcelain wall sconces she
thinks we should mount inside the boat. It's a 14' boat with 3 benches, but
hey...there's always room for more accessories. I'll probably mount the
generator to a wooden raft that we'll tow behind the boat.

"RG" wrote in message news:CsYdb.8639$Rd4.2926@fed1read07...

No...mind's not made up. When I bought my present battery, I wasn't
aware
of
AGM versions.

Here's some info to bring you up to speed on AGM's:

http://www.lifelinebatteries.com/batterytypes.asp

http://www.dcbattery.com/lifeline2.html

http://www.mastertech-inc.com/lifeline/lifeline.html

http://www.pacificpowerbatteries.com/marinebatts.html

http://www.vonwentzel.net/Battery/00...ary/index.html

http://www.vonwentzel.net/Battery/01.Type/index.html

http://www.vonwentzel.net/Battery/04.Costs/index.html

http://www.vonwentzel.net/Battery/06...ion/index.html

Gel cell batteries - why?

"Doug Kanter" wrote in message
...
Thank you! Yet ANOTHER place to spend my money. But, isn't that what boats
are for? My girlfriend has found some elegant porcelain wall sconces she
thinks we should mount inside the boat. It's a 14' boat with 3 benches,
but
hey...there's always room for more accessories. I'll probably mount the
generator to a wooden raft that we'll tow behind the boat.

I bought three of the group 27 Lifelines two years ago and haven't so much
as looked at them since I installed them. They are installed in an
extremely high heat situation, which would otherwise have killed off normal
wet cells batteries by this time (as it did the OEM batteries that came with
the boat). I have not been able to detect any degradation of performance
since they were new. At $150 each, they are priced probably a little more
than double what a generic discount group 27 deep cycle would cost. But
when you combine their increased performance and safety with the fact that I
no longer have to stand on my head to do battery maintenance, money very
well spent for me. Friends of mine that have bought them on my
recommendation are equally as pleased with them. When it comes time to
replace the batteries in my truck, I'll install AGM's.