DEEP CYCLE BATTERIES for your BOAT
The type of boat that this article is referring to is
perhaps the bigger boat that may occasionally take to the sea and do longer
journeys, perhaps up and estuaries or fishing using nets.
Some canal boats also come into this category, especially if
they are lived in for most of the time and use electricity for such things as
freezers and TV sets. This also includes vessels that use bilge pumps and other
electrical equipment for most of the day, I am also thinking about inverters.
The correct batteries for this application are deep cycle batteries.
How can you tell if you have deep cycle batteries or not?
Deep cycle batteries usually have a reserve capacity or RC
for short. This is the reserve capacity that a battery requires to maintain a
useful voltage and is measured by the number of minutes it takes to hold onto a
reasonable voltage when under a 25 ampere discharge. The RC reference will only
be on the label of a deep cycle battery, if the label reads a Amp-Hour or CCA
(cold cranking amp) reference then it likely that the battery is starter
battery and will NOT be suitable for the purpose of deep cycling.
In my opinion, this where many this is where many people go
wrong. They look on the internet or Ebay and see the cheaper leisure batteries
advertised, thing that they are the thing that they want. Most of these leisure
batteries are OK for a motor home or caravan, but they are not deep cycle
batteries and will not last two minutes when used on a boating situation.
The genuine deep cycle batteries are made using much thicker
plates and lead grids, which are the things that hold the plates together. The
rest of the materials used such as the oxides and separator materials are made
of much heavier duty materials, in order to give this type of battery a much
deeper capacity. The cranking batteries that are used as car starter batteries
are made of much lighter materials that make them much cheaper than the deep
cycle batteries and they are only used to produce enough power to start a car’s
engine and not to store large amounts of power.
More reading... http://www.sailnet.com/forums/electrical-systems/63682-battery-confusion-amp-hours-vs-reserve-capacity.html
The starter battery cannot be used as a storage battery but
the deep cycle battery can be used for both starting and storage.
The thing to look out for as I have said earlier is the RC rating
and the higher the rating the better. You should get the biggest battery that
you can fit into your battery compartment, without DE-stabilising your boat? Remember
these batteries are very heavy due the heavy duty materials that they are made
of.
You should buy the biggest deep cycle battery that will fit
your boat, it will last much longer and give your battery a longer life by not
having to use as many discharge and recharge cycles. For example this same
battery might last 650 cycles if it is only discharged 50 percent on each
fishing day, 1,500 cycles if discharged only 25 percent and 3,500 cycles if
discharged only 10 percent.
The bottom line is that you pay for what you get, like
anything in life. The bigger battery that you can afford that is deep cycle
with a high RC rating the longer it will last you in the long run and the
better service you will get out of your battery.
Some systems on the larger boats also run on 36 volt and 24
volt systems, so that is well worth watching out for. AGM are the most popular
type of battery that is used. The AGM stands for (absorbed glass matting). The
glass matting absorbs the electrolyte and so there is no liquid in the cells.
The batteries can therefore be sealed and will not leak even if the battery
casing is punctured. This type of battery can charge and re-charge faster than
a flooded battery, but the downside is that they are heavier and more expensive
to buy in the first place.
Gel batteries are also maintenance free similar to the AGM
batteries, but are filled with a gel additive which sets in the battery making
them maintenance free batteries. Both GEL and AGM batteries work under a slight
amount of internal pressure and are equipped with a release valve should the
pressure exceed the limits, due to excessive heat either in charging or
operating conditions.
The difference is that you should not use the same charger
for a GEL and an AGM battery. The GEL battery works at a much lower charge rate
and if an AGM charger was used then the battery will overheat and cook in a
short period of time. In my opinion the GEL battery is falling out of favour
because they are the heaviest and the most expensive of the three different
types of battery suitable for boats, and require a special charger.
So remember choosing the right battery for your needs and
taking good care of it will save you money and keep your boat running longer.
Eric Roberts
Hi I would like to introduce myself. I have worked in the
Garage and tyre and I am MD for online battery company
www.batteriesontheweb.co.uk. I have worked for a couple for national tyre
companies in my younger days, before starting my first business. I now own a
garage and MOT testing centre, here in the UK called Pellon Tyre and
Auto-centre, and I am a keen blogger about anything to do with cars and their
related products that will help my business. We are members of Point-S and
Motor-Codes and are also a Unipart Car Care Centre and of course Tyre-safe.
