Battery Float Chargers

Types Of Battery Chargers           What Is A Float Charger?           How Does A Float Charger Work?           Battery Charging Safety

How Can Battery Life Be Increased?     What Is Battery Self-Discharge?      Battery F.A.Qs      Postive vs. Negative Ground Vehicles



How Do I Charge a  POSITIVE Ground Vehicle?

First, let's differentiate between a negative and positive ground system.  Today, all vehicles have a NEGATIVE ground system.

  This means that the vehicle's steel frame or chassis is directly connected to the negative side of the battery via the negative battery cable.  But prior to 1954, most vehicles had a POSITIVE ground system.

In a positive ground system,the vehicle's steel frame or chassis is directly connected to the positive side of the battery via the positive battery cable. 

In other words, the cable that's attached to the positive post of the battery attaches to the engine block or chassis on the other end.  And the cable that attaches to the negative post of the battery, attaches to the starter solenoid on the other end.

Worth mentioning...If you have never noticed, the terminal posts on a top-post battery are of two different diameters.  The positive post has a larger diameter than the negative. 

Regardless if your vehicle is a negative-ground or positive-ground, if the battery cables are connected properly, the battery cable with the larger diameter terminal will connect to positive battery post, and the battery cable with the smaller diameter terminal will connect to the negative battery post.

Will my battery charger work on a negative ground vehicle?  If so, how do I charge my negative ground battery? 


Will my battery charger work on a POSTIVE ground vehicle?
Yes it will!  All properly rated battery chargers will work on both positive AND negative ground vehicles.  The best way to think about negative vs. positive ground systems is to not think about it at all. It can be confusing. So forget about negative or positive ground.  All you have to remember is to always connect the RED (+) clamp from the battery charger to the POSITIVE side of the battery, and connect the BLACK (--) clamp from the battery charger to the NEGATIVE side of the battery!


During the battery charging process, a battery may be boil, cause sparks, splash acid, discharge hydrogen gas, and/or give off a sulphuric odor. You should take precautions when When connecting a battery to a charger or when servicing a battery. Always wear skin and eye protection such as an apron, rubber gloves, face mask or eye shield, and heavy duty footwear. WHY? Here are some of the personal risks involved:

A. Cotton is eaten by the sulphuric acid in a battery very efficiently, so jeans and heavy shirts offer little to no protection from battery acid. Inevitably, clothing worn in a battery charging environment will have holes. For protection a protective apron works far better.

B. Charging Batteries can get hot, hot acid hurts more than cold acid. So thick, protective clothing is a better idea than the thin stuff. When hot acid is boiling, it splashes everywhere.

C. Flooded Batteries make a mess as they bubble and percolate under charge. This mixes up the acids sure, but it also makes a very good mess. Without protection for your hands, how are you going to clean it up without burns? This can be avoided by buying different batteries.

D. Batteries are heavy, and this adds another danger to the table. When a battery "jumps" off a table, it has enough weight to take off a toe. Do wear heavy footwear when working with batteries.

What is impervious to acid? Nylon and Glass are two of the best materials that stand up to acid. When making purchasing decisions regarding protective materials, do keep this in mind.

Battery Charger Warnings: Always read and follow the manufacturer's battery charging instructions prior to connecting your battery, or trying to charge a battery bank. Do not attempt to charge batteries in a confined environment. Explosive and hazardous gases are an inherent byproduct of battery charging, do think ahead. Batteries contain sulphuric acid, and lead, both of which are hazardous material if removed from the battery, or disposed of improperly, do take care to be environmentally responsible. Batteries are useful, just be safe.

BATTERY F.A.Qs (Frequently Asked Questions)
Do lead acid batteries discharge when not in use?
Yes. All batteries, regardless of their chemistry, will self-discharge even when no load is present. The rate of self-discharge for lead acid batteries depends on the storage, operating temperature and condition of the battery. At a temperature of 80 degrees F, a lead acid battery will self-discharge at a rate of approximately 4% a week. A battery with a 125 amp-hour rating would self-discharge at a rate of approximately five amps per week. Keeping this in mind if a 125 AH battery is stored for four months (16 weeks) winter without being charged, it will loose 80 amps of its 125-amp capacity. As a result of being undercharged, the battery will also have severe sulfation, which causes additional loss of capacity.

A rule of thumb is to ALWAYS keep your batteries fully charged while not in use!

Do lead acid batteries develop a memory?
Lead acid batteries do not develop any type of memory.

Do I need to completely discharge my lead acid battery before recharging it?
No. In fact you should never discharge your lead acid battery below 80% of its rated capacity. Discharging a 12 volt battery below this point, or 10.5 volts, can damage it.

Can my batteries freeze?
Yes. If your battery is partially discharged, the electrolyte in a lead acid battery may freeze. At a 40% state of charge, electrolyte will freeze if the temperature drops to approximately -16 degrees F. When a battery is fully charged the electrolyte will not freeze until the temperature drops to approximately -92 degrees F. Always keep your battery fully charged! Lectric Limited's battery storage chargers makes this process simple and inexpensive.

When should I add water to my batteries?
How often you use and recharge your batteries will determine the frequency of watering. Also, using batteries in a hot climate will require more frequent watering. It is best to check your battery water level frequently and add distilled water when needed. Never add tap water to your battery. Tap water contains minerals that will reduce battery capacity and increase their self-discharge rate.

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?
Battery electrolyte levels should be just below the bottom of the vent well, about - inch above the tops of the separators. Never let the electrolyte level to drop below the top of the plates.

Do I ever need to add acid to my battery?
Under normal operating conditions, you never need to add acid. Only distilled or de-ionized water should be added to achieve the recommended electrolyte levels.

What is battery sulfation and when does it occur?
Sulfation (or Lead Sulfate) is the formation of hard crystals on the plates of your battery. These unwanted crystals are formed by the lead and sulfuric acid in your battery.

Initially, the lead sulfate coating is soft, thin and easily reconverted into lead and sulfuric acid when battery is recharged. It is important to remember, the longer your battery remains discharged, the more it will begin to form hard crystals of lead sulfate…RECHARGE YOUR BATTERY AS SOON AS POSSIBLE! Once these hard crystals form, they are impossible to remove during a standard fixed voltage charging process, and will lead to battery failure. This is why it is so important to keep your battery fully charged at all times!!! Lectric Limited's battery storage chargers makes this process simple and inexpensive.

What are the most common mistakes made by owners of lead acid batteries?

Undercharging - Generally caused by not allowing the charger to restore the battery to full charge after use. Continuously operating a battery in a partial state of charge, or storing the battery in the discharged state results in the formation of lead sulfate (sulfation) on the plates. Sulfation reduces the performance of the battery and may cause premature battery failure.

Overcharging - Continuous-charging causes accelerated corrosion of the positive plates, excessive water consumption and in some cases, damaging temperatures within the battery. Lead acid batteries should be charged after each discharge of more the 50% of its rated capacity and during, or after, prolonged storage of 30 days or more.

Under-watering - In lead acid batteries water is lost during the charging process. If the electrolyte level drops below the tops of the plates, irreparable damage may occur. Check your battery water level frequently.

Over-watering - Excessive watering of a battery results in additional dilution of the electrolyte, resulting in reduced battery performance. Add water to your battery after it has been fully charged, never when the battery is partially discharged.

Do I need a Battery Disconnect Switch?
A battery disconnect switch is always recommended as a safety and security device for vehicles (cars, boats, RVs, etc.) that are being stored, repaired, or not used for an extended period of time (one month or more).  A battery disconnect switch, when disengaged, will isolate your battery from your vehicle.  And if there is no power going to your vehicle's wiring harnesses, cigarette lighter, power plug port, and computer, there is no chance of a wiring short circuit that can lead to damage or, in worst case, a fire. 

Power is disconnected by loosening or removing the knob, or turning the key.  Battery power is restored by tightening the knob or turning the key.

Most disconnects come with a removable knob or key.  This feature allows you to simply remove the knob to completely disable it for added automobile security.

Battery disconnects are rated by peak volts and amperage handling capacity.  Make sure that the disconnect switch you purchase is rated for your type of battery.

 (blue color hex: 006699)

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