8.1. Installing Car and Marine Starting Batteries

8.2. Installing Deep Cycle Batteries

While working with car or deep cycle lead-acid batteries, please wear glasses to protect your eyes in the unlike event of an explosion.

8.1. Installing Car and Marine Starting Batteries

In a 2003 marketing study in the U.S., consumers (or non-professional battery installers) installed almost 60% of the approximately 82 million replacement car batteries that were made in 1999. Car batteries were the fourth most popular item purchased among auto parts. The same study indicated that Wal-Mart (EverStart) has surpassed Sears (DieHard) as the number one car battery seller in the United States with Auto Zone (DuraLast) as the most popular of the U.S. auto parts stores for car batteries.

Some premium vehicle manufacturers, for example, BMW, use coded batteries to the engine, so disconnecting a battery terminal or replacing a battery might disable the vehicle without the proper dealer programming. Please check the owner's manual or dealer before disconnecting a battery terminal. Below are some questions you need to ask yourself because the installation of a replacement battery and disposal of the old one is usually included in the purchase price at some auto parts and battery stores:

If you decide to proceed, following is a list of easy steps to replace your battery and assumes that there the electrical and charging systems are in good condition:

8.1.1. In a well ventilated area, fully charge and test the new battery. Please see Section 9 for charging and Section 4 for testing the battery. If the battery is dry charged (shipped with out electrolyte), use the battery manufacturer's instructions. If not available, add the electrolyte but do not overfill, let stand for approximately one hour, and then slowly charge the battery at no more than 1% of the CCA or 10% of the amp hour capacity.

8.1.2. If a non-sealed wet battery, check the electrolyte levels after the battery has reached room temperature and "top off" the electrolyte to the proper level with distilled, deionized or demineralized water as required, but do not over fill. The plates need to be covered with electrolyte at all times to prevent an internal battery explosion or sulfation. (Please see Section 3.2 for electrolyte fill level information.)

8.1.3. Thoroughly wash and clean the old battery posts, battery cable terminals clamps or lugs and tray (or battery box) with warm water to minimize problems from acid or corrosion. (Please see Section 3.3 for more information on corrosion.)

8.1.4. Mark all of the battery cable terminal clamps or lugs so you will know how to reconnect to proper battery terminal post and check the cables and cable terminal clamps or lugs closely for damage. A loose terminal connection, corrosion, bad crimp (in especially a battery cable terminal clamp or lug with multiple wires into it), or cut cable will cause high resistance and a large voltage drop when high current is running though it. If the battery terminal polarity or cables are reversed, you can do extensive damage to your electrical system.

8.1.5. When you disconnect the car battery, the emmissions computer will reset and the engine might run differently until the computer relearns the optimum settings. Be sure that you have saved any required immobilizer, security system or radio codes that will have to be reentered. To save the radio station presets, emissions computer, clock, immobilizer, or security system code settings, temporarily connect a "Computer Memory or Setting Saver" or a second 12-volt battery in parallel (positive to positive and negative to negative) to the electrical system before disconnecting the first battery. Cigarette lighter adapter or "Computer Memory or Setting Saver" with a 9-volt battery are available at most auto parts, battery or electronics stores, for less than $10. If you use the cigarette lighter adapter receptacle, insure that it is active before disconnecting the battery.

8.1.6. Turn off all electrical and electronic accessories and appliances. Do not use a hammer on the battery cable terminals or posts. Remove the grounded cable first because this will minimize the possibility of shorting the battery when you remove the other cables. The grounded cable is normally the NEGATIVE (-) cable, but it could be the positive cable in some older vehicles. Secure the grounded cable so that it cannot "spring" loose and make electrical contact. Next remove the remaining cable which is normally POSITIVE (+). Please remember that the battery terminal connector on the end of the POSITIVE (+) battery cable maybe "hot" (or have voltage on it from a parallel battery), so put it in a small plastic bag or cloth around it. This is so that it will not contact the metal frame or engine components. If necessary mark the polarity of the cables. Also remember (or take a picture of) the exact location of the battery posts that the terminals were connected to prevent reversing the polarity of the terminals when installing the replacement battery.

8.1.7. Carefully lift the old battery out and dispose of it by exchanging it when you buy your new replacement battery or by taking it to a recycling center. For the location of recycling centers, go to http://www.recyclingmybattery.com/. Please remember that batteries are heavy and contain large amounts of harmful lead, acid and other chemicals, so take great care with safety and disposal of your old battery properly to protect the environment. BCI reports in 2014 that approximately 99% of the lead from lead-acid batteries was being recycled in the United States.

8.1.8. After removing the old battery, insure that the battery tray or box and cable lugs/terminals are clean and free of corrosion. Auto parts or battery stores sell an inexpensive brass wire brush that will clean the inside of terminal clamps or lugs and the terminal posts. If the terminals, cables or hold-down brackets are corroded, replace them. A broken or loose hold down bracket will cause excessive battery vibration and that will cause a premature battery failure. Replace any battery cables that are corroding, swelling or other damage with equal or larger diameter cable. Larger diameter cable is better because there is less voltage drop.

8.1.9. Check the positive and negative terminal markings on the replacement battery and position it so that the NEGATIVE (-) cable will connect to the NEGATIVE (-) terminal. Reversing the polarity of the electrical system can severely damage or DESTROY it or the battery.

8.1.10. After replacing and tightening the hold-down bracket. Use of Nyloc self locking nuts will help prevent loose hold-down clamps. Remove any plastic caps or covers on the terminals of the replacement battery and reconnect the cables in reverse order, that is, attach the POSITIVE (+) cable first and the NEGATIVE (-) cable last. For General Motors-type side terminals, check the length of the bolt and do not tighten more than 4.2 to 5.8 foot pounds, or you could crack the battery case. For top terminals, do not tighten more than 5.8 foot pounds and 10 to 15 foot pounds for stud terminals. Connections need to be periodically checked for corrosion (or oxidation) and retightened, including the grounding cables between the vehicle's frame and engine block. If a parallel battery or "Computer Memory or Settings Saver" was used, disconnect it.

8.1.11. To prevent corrosion, coat the terminals and exposed metal parts with high temperature grease or silicone. Please see Section 3.3 for more information on corrosion.

8.1.12. Remove the parallel battery and reset all the switches and breakers, if required.

8.1.13. Test the new battery by starting your engine or with an electrical load.

Some vehicles have battery electrolyte level sensor that will need to be reconnected.

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8.2. Installing Deep Cycle Batteries

Most of the steps above for installing car batteries apply to installing deep cycle batteries with these notable exceptions. Wire sizing and cable lengths are very important because wiring that is not large enough or different lengths will cause excessive voltage loss and undercharged batteries or, in some cases, a fire. Where vibration is present, wiring should be installed in a flexible protective covering or conduit to protect it. Gromments should also be used when the wire is run through any openings than cut the insulation. According to the U.S. Fire Administration from 2008 to 2010, 22% of highway vehicle fires were caused an electrical failure or malfunction such as a short. A good voltage loss table can be found at Wind & Sun. Wiring size (and fusing) should be based on the maximum possible current carried through the wire. Please note that SAE (Society of Automotive Engineering) wire is up to 12% smaller than AWG (American Wire Gauge) wire. To better balance the voltage with batteries in parallel, wire the connections from the POSITIVE (+) battery terminals to a single positive (+) distribution point and the connections from the NEGATIVE (-) battery terminals to a single NEGATIVE (-) distribution point. All of the interconnecting leads between the battery terminals and distribution points need to be exactly the same wire size and length so the voltage is the same. For parallel and series wiring diagrams, please see Section 7.3.2. Use of bus bars is highly recommended for larger deep cycle battery bank installations.

Other good sources of information of wire sizing can be found at Wind & Sun, PowerStream or Solar Expert. Using properly sized fuses or circuit breakers is also very important because they can provide protection for the wiring from over heating and for the electrical appliances. Good sources of basic information on connectors, fuses and wire can be found on howstuffworks or Perry Babin's Basic Car Audio Electronics Web site at http://www.bcae1.com/fuses.htm/ and http://www.bcae1.com/wire.htm/. Most rotary A/B battery selector switches are not recommended because the heavy inrush of current during the first few milliseconds that a switch is closed can burn the contacts or arc. Series, parallel, and series-parallel battery connection wiring diagrams can be found in Section 7.3.2. Connections will need to be periodically retightened.

Insure there is adequate ventilation for the batteries so gases can dissipate while recharging and batteries can stay cooler. In other words, do NOT use sealed battery boxes, even with sealed Gel Cell (Ca/Ca) or AGM (Ca/Ca) VRLA batteries, because if there is shorted cell, a great deal of gassing could occur. Some batteries will require up to 50 "preconditioning" cycles before they will produce their rated capacity. This is because the acid needs to fully penetrate the pores of the newly formed plates. When mixing sulfuric acid and water to make electrolyte for dry charged batteries, always slowly add the acid to the water and NEVER add water to acid as it may boil violently and splatter.

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