Batteries Article

8/4/2019 Batteries Article

http://slidepdf.com/reader/full/batteries-article 1/6

Deep Cycle Batteries

What do you really know about themBy : Bob “River Rat “ Koeshall

Every fisherman has from one to four deep cycle batteries in

their boat. Some fisherman remove them from their boat at

the end of the fishing season, some leave them in the boat.

Some trickle charge them all winter, some charge them once

in a while. Is there a right way or a wrong way to maintain your deep cycle battery .

I hope to answer this question, and give you some information that you will find

very useful. Unless you are quite wealthy, you will want to take care of your

batteries, and they will take care of you for a long time. Average battery life has

become shorter as energy requirements increase. Life span depends on usage; 6

months to 48 months, yet only 30% of all batteries actually reach the predicted life

span . Proper maintence, and understanding how your battery works is necessary

to achieve this. First lets see just how a Deep cycle battery works. The Lead acid

battery is made up of plates, lead and lead oxide (various other elements are used to

change density, hardness, porosity, etc.) with a 35% sulfuric acid and 65% water

solution. This solution is called electrolyte which causes a chemical reaction that

produce electrons. When you test a battery with a hydrometer you are measuring

the amount of sulfuric acid in the electrolyte. If your reading is low, that means the

chemistry that makes electrons is lacking. So where did the sulfur go. It is stuck to

the battery plates and when you recharge the battery the sulfur returns to the

electrolyte. Deep cycle batteries have thicker plate design and can survive over a

hundred discharge cycles.

There are simple steps in testing a deep cycle battery: inspect, recharge, remove

surface charge, measure the state-of-charge, load test, and recharge. If you have anon-sealed battery, it is highly recommended that you use a good quality

temperature compensated hydrometer; these can be purchased at an auto parts

store for between $5 and $20. A hydrometer is a float type device used to determine

the state-of-charge by measuring the specific gravity of the electrolyte in each cell.

It is a very accurate way of determining a battery’s state-of-charge and its weak or

dead cells. To troubleshoot charging or electrical systems or if you have a sealed

battery, you will need a digital voltmeter with 0.5% or better accuracy. A digital

voltmeter can be purchased at an electronics store like Radio Shack for between $20

and $50. Analog voltmeters are not accurate enough to measure the millivolt

differences of a battery’s state-of-charge, or the output of the charging system. The

purchase of a battery load tester is optional; these run about $ 70 at auto partsstores. If you use your electric trolling motor every day, as I do then buy one. A

more accurate way of testing the capacity of a lead acid battery is by using a

conductance tester.

Ok, so lets visually inspect the battery for obvious problems. Check the electrolyte

levels. Is the level below the top of the plates, are the cables corroded, corroded

terminal clamps, dirty or wet battery top, loose hold-down clamps, loose cable

terminals, or a leaking battery case. If the electrolyte levels are low in non-sealed



batteries, allow the battery to cool and add distilled water to the level indicated by

the battery manufacturer. If this is not indicated, use ¼ inch below the bottom of

the plastic filler tube vent wells. The plates need to be covered at all times. Do not

overfill the cells, especially in hot weather, because heat will cause the electrolyte to

expand and overflow.

Breakdown of the grid-paste interface occurs when a calcium battery is dischargedrepeatedly, resulting in battery capacity losses of 40% or more. Additional

maintenance expenses are incurred as a result of the battery’s premature failure.

The lead antimony battery will withstand repeated charge/discharge cycles and will

generally accept charge more readily than a calcium battery. However, the higher

charge acceptance of the antimony battery causes increased water consumption and

the resultant external corrosion problems associated with the sulfuric acid fumes

being carried out for the battery in the evaporation process. If the lead antimony

battery is not properly maintained, battery trays and cables will require regular

replacement due to corrosion and boil over problems. To achieve longer battery life,

the lead antimony battery requires frequent water additions to maintain proper

electrolyte levels and the corrosion must be regularly removed from posts, cables,hold-downs, and battery trays.

Thanks to the latest in modern technology, a product called THERMOIL has been

developed to reduce, if not completely solve today’s battery problems. Most folks

don’t know that just the gases from the battery condensing on metal parts cause

most corrosion. As I stated above, Thermoil® is a unique and patented inexpensive

battery additive that when added to your new or existing battery will increase

battery life, increase shelf life, eliminate corrosion, greatly reduces water

consumption, explosion, toxic fumes and will help to keep your battery working

under any condition from -50º to 400º Fahrenheit and is Guaranteed 100%. This

product is a must for all lawn mower, motorcycle, car, truck, boat, RV, bus, tractor,

utility, scrubber, sweeper, golf cart, solar or any other new or used non-sealed leadacid battery. I use Thermoil in every battery I have, and believe me; it works

exactly as the manufacture said it would. If you go to their web site at

www.thermoilbatteries.com you can order it from there and you will be happy that

you did. Make sure you read their FAQ’s, this will explain how the product works

and why Thermoil now sells mainly the oil instead of the batteries like they used to.

No more wet tops on your batteries, no more corrosion on the battery posts, and

cables, this is a great product, and I know several in the RV industry that

recommend it to all there customers because it really works.

NEXT RECHARGE THE BATTERY TO 100% STATE-OF-CHARGE.There are up to four phases of battery charging: bulk, absorption, equalization and

float. The bulk stage is where the charger current is constant and the battery

voltage increases. You can give the battery whatever current it will accept not to

exceed 20% of the ampere-hour rating and this will not cause overheating. The

absorption phase is where the charger voltage is constant and current decreases

until the battery is fully charged. This normally occurs when the charging current



drops off to 1% or less of the ampere-hour capacity of the battery. For example, the

ending current for a 100 ampere-hour battery is 1.0 amp or less.

REMOVE THE SURFACE CHARGE

Surface charge is the uneven mixture of sulfuric acid and water within the surface

of the plates as a result of charging or discharging. It will make a weak battery

appear good or a good battery appear bad. You need to eliminate the surfacecharge by one of the following methods: Allow the battery to sit for four to twelve

hours to allow for the surface charge to dissipate. Apply a load that is 33% of the

ampere-hour capacity for five minutes and wait five to ten minutes. With a battery

load tester, apply a load of at least one half the battery’s CCA rating for 15 seconds

and wait five to ten minutes.

Follow the battery and charger manufacturer’s procedures for connecting and

disconnecting cables and other steps to minimize the possibility of an explosion or

incorrectly charging the battery. You should turn the charger OFF before

connecting or disconnecting cables to a battery. Do not wiggle the cable clamps

while the battery is recharging, because a spark might occur, and this could cause

an explosion. Good ventilation or a fan is recommended to disperse the gassescreated by the recharging process. If a battery becomes hot, over 110° F (43.3° C),

or violent gassing or spewing of electrolyte occurs, turn the charger off temporarily

or reduce the charging rate. If you are recharging gel cell batteries, a

manufacturer’s list of charging voltages can be very critical. Sometimes, you might

need special recharging equipment. In most cases, standard deep cycle chargers

used to recharge wet batteries cannot be used to recharge gel cell and AGM

batteries because of their charging profiles; using them will shorten battery life or

cause “thermal runaway”. Match the charger (or charger’s setting) for the battery

type you are recharging or floating.

Use an external constant current charger, which is set not to deliver more than 12%

of the RC rating of the battery and monitor the state-of-charge. Timers that willcut-off the charger will help prevent overcharging the battery.

The best method is to slowly recharge the battery at 70° F (21.1° C) over a 10 to 20

hour period (C/10 to C/20) using an external constant voltage (or tapered current

charger) because the acid has more time to penetrate the plates and there is less

mechanical stress on the plates. C-rate is a measurement of the charge or discharge

of battery overtime. It is expressed as the Capacity of the battery divided by the

number of hours to recharge or discharge the battery. For example, assume that

the ampere-hour capacity of the battery is 220, then it would take 11 hours to

recharge or discharge the battery using a C/20 rate. A constant voltage or

“automatic” charger applies regulated voltage at approximately 13.8 to 16 volts,

based on the manufacturer’s recommendations and temperature. A 10 ampconstant voltage charger will cost between $30 and $60 at an auto parts store is

suitable for most simple recharging or charging applications. If left unattended,

cheap, unregulated trickle or manual battery chargers can overcharge your battery

because they can “decompose” the water out of the electrolyte. Avoid using fast,

high rate, or boost chargers on any battery that is sulfated or deeply discharged.

The electrolyte should never bubble violently while recharging because high

currents only create heat and excess explosive gasses.



Recharging slowly and keeping your battery well maintained are the best ways to

extend the life of your battery. Recharge a deep cycle battery as soon as possible

after each use to prevent sulfating. In warmer climates and during the summer,

“watering” is required more often. Check the electrolyte levels and add distilled

water, if required. Never add electrolyte to a battery that is not fully charged, just

add distilled water and do not overfill. The plates must be covered at all times. Highambient temperatures (above 80%deg; F ) will shorten battery life because it

increases positive grid corrosion and growth.

WHAT ARE THE MOST COMMON CAUSES OF PREMATURE BATTERY

FAILURES?

Loss of electrolyte due to heat or overcharging. Undercharging. Old age (positive

plate shedding) or ”Sludging”. Excessive vibration. Freezing or high temperatures.

Using tap water which causes calcium sulfating. Positive grid corrosion or growth

due to high temperatures.

HOW CAN I STORE BATTERIES?

When in storage, recharge when the state-of-charge drops to 80% to prevent lead

sulfating. Maintaining the correct state-of-charge while in storage, electrolyte levels,tightening loose hold-down clamps and terminals, and removing corrosion is

normally the only preventive maintenance required for a deep cycle battery. Avoid

“opportunity charging.”

Batteries naturally self-discharge 1% to 15% per month while in storage, and lead

sulfating will start occurring when the state-of-charge drops below 80%. If left in a

vehicle, disconnecting the negative cable will reduce the level of discharge by

eliminating the parasitic load. Cold will slow the self-discharge process down and

heat will speed it up. Use the following simple steps to store your batteries:

Physically inspect for damaged cases, remove any corrosion, and clean and dry the

battery tops.

Fully recharge the batteries.Check the electrolyte levels and add distilled water as required, but avoid

overfilling.

Store in a cold dry place, but not below 32° F (0° C).

Depending on the ambient temperature and self-discharge rate, periodically test the

state-of-charge When the state-of-charge drops below 80%, recharge the batteries .

An alternative would be to connect an automatic voltage regulated, solar panel or

“smart trickle” charger to “float” batteries. Based on the manufacturer’s

recommendations, use an automatic or smart charger that has been manufactured

for this purpose and battery type.

WHAT ARE SOME OF THE MYTHS ABOUT BATTERIES?

Storing a battery on a concrete floor will discharge them. A hundred years agowhen battery cases were made of porous materials, such as wood, storing batteries

on concrete floors would accelerate their discharge. Modern battery cases, made of

polypropylene or hard rubber, which are better sealed, so external leakage, causing

discharge, is no longer a problem. However, the top of the battery must be clean

and dry. Temperature stratification within large batteries could accelerate the

internal “ leakage” or self-discharge if the battery is sitting on a cold floor in a

warm room.



A battery will not explode.

Recharging a wet lead-acid battery normally produces hydrogen and oxygen gasses.

While spark retarding vent caps help prevent battery explosions, they occur when

jumping, connecting or disconnecting charger or battery cables, and starting the

engine. While not fatal, battery explosions cause thousands of eye and burn injuries

each year.When battery explosions occur when starting an engine, here is the usual sequence

of events: One or more cells had a high concentration of hydrogen gas (above 4.1%)

because the vent cap was clogged or a defective valve did not release the gas. The

electrolyte levels fell below the top of the plates due overcharging, or poor

maintenance. A battery will not lose its charge sitting in storage.

Depending on the type of battery, it has natural self-discharge or internal

electrochemical “leakage” at a 1% to 20% rate per month that will cause it to

become sulfated and fully discharged over time. Higher temperatures accelerate this

process. Batteries stored at 95° F (35° C) will self discharge twice as fast than one at

75° F (23.9° C).

Maintenance free batteries never require maintenance.In hot climates, water in the electrolyte is “decomposed” due to the high

temperatures and normal charging of a wet maintenance free battery. Water can

also be lost due to excessive charging voltage or charging currents. Non-sealed

batteries are recommended in hot climates so they can be refilled with distilled

water when this occurs.

Pulse chargers,

Using pulse chargers or additives is a very controversial subject. Most battery

experts agree that there is no conclusive proof that more expensive pulse charges

work any better than constant voltage chargers to remove sulfating.

Batteries last longer in hot climates than in cold ones.

Batteries last approximately two thirds as long in hot climates as cold ones. Heatkills batteries, especially sealed wet lead acid batteries.

Deep cycle batteries have a memory.

Lead acid deep cycle batteries do not have the so called “memory effect” that first

generation Ni-Cad batteries have.

HOW LONG WILL A DEEP CYCLE BATTERY LAST ON A SINGLE

CHARGE?

Discharging, like charging, depends on a number of factors such as: the initial

state-of-charge, depth-of-discharge, age, capacity of the battery, load and

temperature. For a fully charged battery at 70° F (21.1° C), the ampere-hour rating

divided by the load in amps will provide the estimated life of that cycle. For

example, a new, 72-ampere-hour battery with a 10-amp load should lastapproximately 7.2 hours. As the battery ages, the capacity is reduced. Well, now

you know as much as I know about Deep Cycle Batteries. It seems every one has a

different way of charging their batteries. Some do it correctly, and many DON’T,

and I hope they read this article, as it will help them do it correctly to avoid

spending hard earned money needlessly. Like always, if any of you have any

questions on this article, please feel free to contact me. RiverRat@Fish-

Wisconsin.com [email protected]. I’d like also to



thank my friends at Crestliner Boats, Magic products, Lake-link.com, Fish-

Wisconsin.com, Fishtheriver.com, Hummingbird locators, St.Croix Rods, Harriet’s

Kitchen Nook, Camelot Motel, in Wis.Rapids. Heckels marine, Amherst Marine.

Comprop Prop, ISG Jigs, Reeds Sporting Goods, Big Fish Tackle Co., Ipsglass.com,

Thermoil batteries.com and others who have helped me along the way. This article

may not be reproduced in any way without my written permission.

Batteries Article

Documents

Transcript of Batteries Article