My
Deep Cycle Battery and Trolling Motor Info page
Here
is what I have discovered concerning the use of the trolling motor and deep
cycle battery. Please remember I am not
a expert. This is what I have
discovered from many different sources.
Any of which may be wrong.
Many
people complain that when using a trolling motor the battery does not
last. This is caused by using a
ordinary battery. A vehicle battery is
designed to supply a large amount of power for a very short amount of
time. A trolling motor requires a fair
amount of power for a long time. Because
of this a deep cycle battery is constructed to withstand being drained and
recharged without damage.
You
can tell the charge level of a deep cycle battery using a voltmeter or a
hydrometer. I use a voltmeter. It is less precise but easier to use for a
beginner. My battery is a Nautilus Gold
Battery sold by Canadian Tire. Here is
the table I found for this battery. I
have been informed that every type of battery has its own voltage table and you
should get it from the manufacturer, but here is the table for mine.
Never test a battery with a voltmeter under load. You will get a reading lower then the
correct voltage. Turn off your motor
and other accessories running under the battery before the test. You should also note that when a battery is drained quickly such as with a trolling motor the voltage will climb for about eight hours after the load is taken off the battery. You will have to wait that long for a accurate reading. Obviously if you are on the water and using voltage to determine the level of the battery waiting eight hours is a little impracticle. I take the reading as is. I don't get as much time out of a battery before I concider it discharged however, better safe then sorry.
12.6v
- 100%
12.4v
- 75%
12.2v
- 50%
12.0v
- 25%
11.8v
- 0%
You
may wonder why the voltage for 0% is so high.
That is because you should never drain a deep cycle battery below 70% of
the total capacity. When you reach
11.8v you are at that 70% mark of total capacity and should stop using the battery. Going past this point shortens the life of
the battery.
When
recharging do yourself a favour and get a automatic charger for deep cycle batteries.
I thought that recharging my battery would be easy, but it is a pain. You need to charge the battery up to full
capacity, but there is a catch. The
voltage will drop for 24 hrs after charging.
This is normal, but causes problems if you are using voltage to tell how
much of a charge to put in the battery.
A automatic charger for deep cycle batteries will slowly charge you
battery, and will reduce that amperage being put into the battery as it gets
closer to finishing. This seems to help
with the voltage drop problem and reduces the chances of the battery being
overcharged. Also it will cut out when
the battery is charged and will top it off again as the voltage drops. Canadian Tire sells a Nautilus Charger
Especially for the Nautilus Batteries.
That is what I have.
Battery Sulfurization and Solar Panels - When a battery is partially or completely discharged sulphur builds on the metal plates inside. If this partiall discharged battery is not still being discharged or charged, but is just sitting there the sulphur will begin to harden making recharging the battery back to its original state more difficult. This is sulfurization and it is the leading cause of premature failure of a battery. In motor boats where the battery is continually either being charged, discharged, or is fully charged sulphuization is not as much of a problem as it is in a sail boat where if a battery is partially discharged it is necessary to wait until you return to home where you can recharge it. However permanent sulphuization supposedly will not occur if the battery is under even a tiny charge. Therefore you should be able to avoid sulphurization in a sail boat with just a small solar panel. Personnally I like to have at least a 15 watt panel for each battery to ensure I get at least some power going to the batteries under most conditions. However this is just a personal choice.
RANGE EXTENDERS-Have you ever wondered about those range extenders that are supposed to greatly increase the range of a trolling motor and wondered what they did. Here is what I have found out. It seems the less expensive motors control
engine speed by using a resisting coil, which converts electricity to
heat. It is located in the part of the
engine that is in the water and the heat is dissipated there. The disadvantage is that this system is
highly inefficient. Going from full
power to half power does not save near as much energy as it should because this
system is so inefficient. A more
expensive engine or one with the range extender quickly turns the power on and
off to regulate speed. So if you are at
half power the engine quickly turns the power on and off so that the power is
only on half of the time. The greatly
extends the range of the engine. I have
heard it can extend running time from 5 to 8 times. However the external range extender seem to be impossible to find. I would like to get one for my boat, but have been unable to find one.