I select the right battery for my application?
Proper battery selection may require the assistance of a
knowledgeable battery sales/service technician. Please contact us at +65 6741
7123 or email rpt@renewpowers.
the difference between a deep cycle battery, a starting battery, and a
A deep cycle battery has the ability to be deeply
discharged and charged many times during its service life. It is designed
specifically for powering electrical equipment for long periods of time. An
automotive or starting battery is designed for brief bursts of high current and
cannot withstand more than a few deep discharges before failure. This is why it
is unable to start your car if you accidentally leave the lights on more than a
couple of times. For applications where both engine starting and light deep
cycling are required, a dual-purpose battery is often used. This type of
battery is neither a starting nor a deep cycle battery but rather a compromise
between the two so it performs both functions adequately.
Can I use my Deep Cycle battery as a starting battery?
Deep cycle batteries can be used for engine starting
but starting batteries should not be used for deep cycle applications. A deep
cycle battery may have less cranking amps per pound than a starting battery,
but in most cases a deep cycle battery is still more than adequate for the
purpose of starting an engine.
What are the advantages and disadvantages of gel,
AGM, and flooded lead acid deep cycle?
Generally, gel and AGM batteries have about 20% less
capacity, cost about two times more, and have a shorter cycle life than
comparable flooded lead acid batteries. However, Gel and AGM batteries do not
need watering, are safer (no acid spilling out), can be placed in a variety of
positions, have a slower self-discharge characteristic, and are more efficient
in charging and discharging than flooded batteries (see table below). Gel
batteries are more suitable for deep cycling applications whereas AGM batteries
are more for light cycling and engine-starting applications.
|Self discharge rate (per month)
better? 24 Volt or 48 Volt system?
Higher-voltage systems tend to be more efficient and
put a lower load on the batteries. Factors other than the battery enter into the
system's overall efficiency.
When should I water my flooded batteries?
Water is lost during charging. Therefore, the best time to water your batteries
is always at the end of the charge cycle. However, if the electrolyte level is
extremely low or the plates are exposed to air, add some water to cover the
plates before starting the charge cycle.
How often should I water my flooded batteries?
How often you use your batteries will determine the frequency of watering. For
example, the weekend fisherman may find he only needs to water the batteries in
his boat once a month. While a maintenance supervisor for a golf course might
need to service the batteries in their golf cars every week. Also using
batteries in a hot climate may require more frequent watering. It is best to
check your new batteries regularly as this will give you a good feel for how
often your application will require battery watering. WARNING: A brand new
battery may have a low electrolyte level. Charge the battery first and then add
water if needed. Adding water to a battery before charging may result in
overflow of the electrolyte.
What is the proper electrolyte level?
Liquid levels should be 1/8 inch below the bottom of
the vent well (the plastic tube that extends into the battery). The electrolyte
level should not drop below the top of the plates.
Do you ever add acid to a battery?
Under normal operating conditions, you never need to add acid.
Only distilled, deionized or approved water should be
added to achieve the recommended levels mentioned above. When a battery is
shipped in a dry state or accidental spillage occurs, electrolyte should be
added to the battery. Once filled, a battery should only need periodic water
the proper torque value for my battery connections?
Automotive 50-70 in-lbs
Wingnut 95-105 in-lbs
LPT 95-105 in-lbs
Stud 120-180 in-lbs
LT 100-120 in-lbs>
Button 90 to 100 in-lbs
LT 100-120 in-lbs
WARNING: Do not over tighten terminals. Doing so can result in post breakage,
post meltdown, and fire.
Can a battery freeze?
The only way that a battery can freeze is if it is
left in a state of partial or complete discharged. As the state of charge in a
battery decreases, the electrolyte becomes more like water and the freezing
temperature increases. The freezing temperature of the electrolyte in a fully
charged battery is -92.0oF. At a 40% state of charge, electrolyte
will freeze if the temperature reaches approximately 16.0oF.
reduce my maintenance by not gassing my batteries?
You will reduce the frequency of watering, but will
cause a condition known as stratification where the specific gravity of the
electrolyte is light at the top of the battery and heavy at the bottom. This
condition results in poor performance and reduced battery life.
I tell if a battery is bad?
To determine if the battery system is experiencing a problem,
fully charge the batteries then shut off the charger and remove all electrical
loads. Allow each battery in the system to stand on open-circuit for about one
hour. Measure the voltage of each battery. If the battery voltage spread
exceeds .15 volts for a 6 volt battery, or .30 volts for a 12 volt battery, a
problem is indicated.
does not confirm a problem. When the voltage spread indicates a problem,
confirmation is accomplished by taking electrolyte specific gravity readings
using a hydrometer. If the specific gravity readings show a spread greater than
.030 (30 points), give the batteries an equalization.
What is used to clean a battery and neutralize the
A solution of baking soda and
water. Use 1 lb of baking soda for
every gallon of water.
batteries should be given a full charge before use.
batteries need to be cycled several times before reaching full capacity (50 -
125 cycles, depending on type). Usage should be limited during this period.
cables should be intact, and the connectors kept tight at
all times. Systematic inspection is recommended.
caps should be kept in place and tight during vehicle operation and battery
should be kept clean and free of dirt and corrosion at all times.
should be watered after charging unless plates are exposed before charging. If
exposed add just enough water to cover plate tops by 1/8". Check acid
level after charge. The acid level should be kept 1/4" below the bottom of
the fill well in the cell cover.
used to replenish batteries should be distilled or treated not to exceed 200
T.D.S. (total dissolved solids...parts per million). Particular care should be
taken to avoid metallic contamination (iron).
best battery life, batteries should not be discharged below 80% of their rated
capacity. Proper battery sizing will help avoid excessive discharge.
chargers should be matched to fully charge batteries in an
eight hour period. Defective chargers will damage batteries or severely reduce
charging at temperatures above 120°F or ambient, whichever is higher.
cycle batteries need to be equalized periodically. Equalizing is an extended,
low current charge performed after the normal charge cycle. This extra charge
helps keep all cells in balance. Actively used batteries should be equalized
once per week. Manually timed charges should have the charge time extended
approximately 3 hours. Automatically controlled chargers should be unplugged
and reconnected after completing a charge.
situations where multiple batteries are connected in series, parallel or
series/parallel, replacement battery(s) should be of the same size, age and
usage level as the companion batteries. Do not put a new battery in a pack
which has 50 or more cycles. Either replace with all new or use a good used
battery testing is an important preventative maintenance procedure. Hydrometer readings of each cell (fully charged) gives an
indication of balance and true charge level. Imbalance could mean the need for
equalizing; is often a sign of improper charging or a bad cell. Voltage checks
(open circuit, charged and discharged) can locate a bad battery or weak
battery. Load testing will pick out a bad battery when other methods fail. A
weak battery will cause premature failure of companion batteries.
use a matched voltage charger and battery pack system. An undersized charger
will never get the job done, no matter how long you let it run. An oversized
charger will cause excess gassing and heat; this situation could cause
explosions or other damage.
batteries age, their maintenance requirements change. This means longer
charging time and/or higher finish rate (higher amperage at the end of the
charge). Usually older batteries need to be watered more often. And, their
acid batteries should be brought up to full charge at the earliest opportunity.
Avoid continuously operating batteries in a partially charged condition. This
will shorten their life and reduce their capacity.
temperatures can substantially affect battery performance and charging. Cold
reduces battery capacity and retards charging. Heat increases water usage and
can result in overcharging. Very high temperatures can cause "thermal
run-away" which may lead to an explosion or fire. If extreme temperature
is an unavoidable part of an application, consult a battery/charger specialist
about ways to deal with the problem.
can be extremely harmful to all lead acid batteries. If seasonal use is
anticipated, we recommend the following:
Completely charge the battery before storing.
Remove all electrical connections from the battery, including series/parallel
Store the battery in as cool a place as possible. However, do not store in a
location which will
be below 32°F. Batteries will discharge when stored, the lower
the temperature the
the self discharge.
When not in use, boost every two months.
a battery's state of charge be accurately measured?
The state of charge of a lead acid battery is most accurately determined by
measuring the specific gravity of the electrolyte. This is done with a
voltage also indicates the
level of charge when measured in an open circuit condition. This should be done
with a voltmeter. For an accurate voltage reading, the battery should also be
allowed to rest for a period sufficient to let the voltage stabilize.
When do I need to perform an equalization charge (only for flooded
Equalizing should be performed when a battery is first purchased (called a
freshening charge) and on a regular basis as needed. How often this might occur
with your battery will vary depending on your application. You will need to
monitor your battery voltage and specific gravity to determine when
equalization is needed. For example, it is time to equalize if the measured
specific gravity values are below manufacturer's recommended values after charging (recommended value for Trojan Deep Cycle
batteries is 1.277 +/- .007 at 80o F). Equalizing is also required
if the specific gravity value of any individual cell varies 30 points or more.
Reduced performance can also be an indicator that equalizing is necessary.
Equalization should also be performed when individual battery voltages in a
battery pack range greater than 0.15 volts for 6 volt batteries or 0.30 volts
for 12 volt batteries.
Does my deep cycle battery develop a memory?
Lead acid batteries do not develop any type of memory. This means that you do
not have to deep discharge or completely discharge a battery before recharging
it. For optimum life and performance, we generally recommend a discharge of 20
to 50% of the battery’s rated capacity even though the battery is capable of
being cycled to 80%.
Do batteries self-discharge when not in use?
All batteries, regardless of their chemistry, self-discharge. The rate of
self-discharge depends on the type of battery, the age of the battery, and the
storage temperature the batteries are exposed to. As an estimate, Trojan
batteries self-discharge approximately 4% per week at 80o F.
What type of charger should I buy?
An automatic charger offers the greatest convenience. Just plug the battery
into the charger and the charger does the rest. Manual chargers, although
equally effective at charging batteries, require a greater level of attention.
Generally speaking, automatic chargers are priced higher than manual chargers.
What size charger should I buy?
A properly sized charger takes into account battery capacity and the time
interval between charges. In applications where cycling is infrequent, such as
weekend RV users, or infrequent or seasonal trolling motor usage, a charger
with an output current rating between 10 and 13% of the battery's rated 20-hour
capacity will suffice. In applications where battery recharge must be
accomplished within 8 to 10 hours, a three stage, automatic charger, rated at
20% of the battery capacity, may be required.
•Example: A good charging rate for a battery with a 20-hr capacity of 225 amp-hr is about 22 to 29 amps. You can of course go
slightly higher or lower depending on what is available on the market.
temperature affect the performance of my batteries?
At higher temperatures (above 77oF) battery capacity generally
increases, usually at the cost of battery life. Higher temperatures also
increase the self-discharge characteristic. Colder temperatures (below 77oF)
will lower battery capacity and prolong battery life. Cooler temperatures will
slow self-discharge. Therefore, operating batteries at temperatures at or
slightly below 77oF will optimize both performance and life.
How do I determine my battery capacity when it is colder/hotter?
capacity is basically a linear
relationship. A good rule of thumb is that for every 15oF above 77oF,
capacity is increased by 10% and for every 15oF below 77oF, capacity is reduced by 10%.
How do I account for temperature when taking my gravity readings?
Temperature will affect specific gravity readings. As temperature increases,
the electrolyte solution expands and as temperature decreases the electrolyte
solution contracts. As a result, it is a good practice to temperature correct
specific gravity readings. Here are the relationships Trojan recommends using:
For every ten degrees above 80oF add 3 points to the hydrometer
•Example: @ 90oF the hydrometer reads: 1.250 The actual reading: 1.250 + .003 = 1.253
For every ten degrees below 80oF subtract 3 points from the
•Example: @ 70oF the hydrometer reads:
1.250 The actual reading: 1.250 - .003 = 1.247
How do I account for temperature when taking my voltage readings?
Temperature will affect voltage readings. As temperature increases, voltage
decreases. Conversely, as temperature decreases, voltage increases. Here are
the relationships Trojan recommends using:
For every 10 degrees below 80oF, add .028 volt per cell to the
charger voltage setting.
•Example: A 12 volt battery @ 70oF. The
recommended charging voltage (@ 80oF) is 14.60 volts. The adjusted
charging voltage is 14.60 +(6 cells * .028vpc) = 14.77
For every 10 degrees above 80oF, subtract .028 volt per cell to the
charger voltage setting.
•Example: A 12 volt battery @ 90oF. The
recommended charging voltage (@ 80oF) is 14.60 volts. The adjusted
charging voltage is 14.60 -(6 cells * .028vpc) = 14.43
Is there a maximum temperature for charging my batteries?
When charging lead acid batteries, the temperature should not exceed 120oF.
At this point the battery should be taken off charge and allowed to cool before
resuming the charge process.
acid batteries recyclable?
Lead acid batteries are 100% recyclable. Lead is the most recycled metal in the
world today. All the lead purchased by Trojan Battery Company for grid and
small parts casting is recycled lead. The plastic containers and covers of old
batteries are neutralized, reground and used in the manufacture of new battery
cases. The electrolyte can be processed for recycled waste water uses. In some
cases, the electrolyte is cleaned and reprocessed and sold as battery grade
electrolyte. In other instances, the sulfate content is removed as Ammonia
Sulfate and used in fertilizers. The separators are often used as a fuel source
for the recycling process.
Where do I recycle my old batteries?
Old batteries may be returned to the battery retailer, automotive service
station, a battery manufacturer or other authorized collection centers for
recycling. If you are not sure where to take your spent batteries, call your
local Trojan dealer for assistance.
What are some common
myths associated with batteries?
• Half of a non-buffered aspirin in each cell and then a fast charge
breaks up sulfation and extends battery life- Aspirin forms ascetic acid which attacks the positive grid and active material.
• Storing a battery on concrete will discharge it quicker- Long
ago, when battery cases were made out of natural rubber, this was true. Now,
however, battery cases are made of polypropylene or other modern materials that
allow a battery to be stored anywhere. A battery’s rate of discharge is
affected by its construction, its age, and the ambient temperature. The main
issue with storing on concrete is that if the battery leaks, the concrete will
Why do manufacturers use different alloys in their batteries
(lead-calcium, lead-antimony, lead-selenium, etc.)?
The composition of the plate grid alloy can have a major effect on operating
characteristics, such as behavior on float charging and cycle life. Older
lead-antimony designs have good cycling capability but require frequent water
additions, particularly towards the end of life, due to antimony migration
between the plates. Cells with lead-calcium alloys require far less watering,
but tend to have a poor cycle life. Lead-selenium alloys are actually
low-antimony types with the addition of selenium as a hardening agent. Such
alloys promote good cycling capability, while maintaining a constant and fairly
low level of water consumption. Many variants on these alloy types are
How do you read the date codes on the batteries?
Positive Terminal- Manufacturing Date. This code indicates the actual date when mechanical assembly of the battery was
completed. At this point, electrolyte has not been added to the battery and
formation charging has not taken place. LETTER stands for the month and could
be anything from A to L (A=January, B=February, C=March, and so on),; NUMBER stands for the date.
Negative Terminal- Shipping Date. This code indicates the month and year when the battery was shipped out of our
factory. LETTER stands for the month (see below); NUMBER is the last digit of
•Example: A battery with “I26” stamped on the positive terminal and “J2” on the negative. “I26” means that the battery was assembled, without electrolyte,
on September 26th. “J2” means that it was shipped from
our factory around October of 2002.