What Stops A Car Battery From Overcharging?

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When the engine of a vehicle is running, the alternator in the vehicle will help to charge the battery in such a way that though it is supplying many parts of the car, it will still stay sufficiently charged and will be able to start the car when the time comes. For some reason, the battery may not be able to retain the charge deposited in it and hence cannot serve as it should in starting the car. (Read Also: Can I Charge A Car Battery With UPS? Find Out Now)

This can be due to the inability of the battery to receive charging or other reasons that may interfere with the charging process. Sometimes, the battery can end up being over-charged for one reason or the other.

So what stops A car battery from overcharging? Overcharging can kill a battery quicker than most things. When this happens, it is because the voltage regulator, which is the component that prevents the battery from getting overcharged, has failed to control the process. 

Modern cars are equipped with an alternator that has an in-built voltage regulator. The voltage regulator puts a check on or restricts the number of electrical charges that eventually get to the battery. Hence, should this regulator fail, the battery is very liable to be over-charged. Can A Car Battery Be Over-Charged?

Of course, a car battery can get overcharged and several reasons can be indicted for this nasty and wasteful development.

Table Of Contents

What Causes A Car Battery Over Charging?

Yes, a car battery can be overcharged easily and this happens regularly.  Over-charging can happen when the voltage regular in the alternator fails to control the whole process. Additionally, a car battery can become over-charged due to what may be called human error.

(Read Also: How Far Can I Drive With A Dead Alternator? Find Out)

For instance, it is quite possible to overcharge a battery when one does not really know how to go about the entire charging process. This happens when incorrect volts or high amp setting on a charger leads to the battery overheat or sudden fast charging that is ineffectual.

This phenomenon of overcharging can also result from leaving the charger on for too long and also unattended to. There are other ways a car battery can get over-charged but these are some of the commonest.

How Do I Diagnose Over Charging In A Car battery?

There are many ways via which you can tell overcharging in a battery. Below are a few of them:

1. High Multimeter Readings

With a multimeter, you can check the volts of your battery while the engine is still running. Ideally, a fully charged battery should read anything from around 12.6 volts and above which translates to about 2.1 volts per every six internal cells.

The moment the car starts without a load of any extras such as lights, radios, AC and fan, the volts will rise to about 14 volts. If for whatever reason the multimeter reads more than 14.8 volts, the alternator should be checked for over-charging.

This high voltage may or may not vary much with changes in engine speeds. Furthermore, voltmeter readings should be high on starting the car but will eventually settle down to normal value, but where you are dealing with an overcharging alternator, the multimeter will maintain its high reading well after starting the car. (Read Also: How To Recharge A Car Battery Unturned)

2. Low Battery Electrolyte

One feature that points out an over-charging car battery is low electrolyte content because over-charging produces heat which causes the electrolyte to evaporate and as it evaporates, the battery retains fewer charges thereby causing more heat generation and more electrolyte loss. It is indeed a vicious cycle.

3. Burnt Bulbs

When the battery overcharges, heat is generated, and also the bulbs in headlights, tail lights, interior lights, and so on, will unavoidably die prematurely. In addition, fuses may also blow either singly or en masse. Even your dashboard lights may blow out too.

4. Battery Heating Up

When a battery is overcharged, the plates inside it may shed their materials and hence lose the capacity to hold electricity. The battery, in turn, may resist any further charging and hence the excess electricity will lead to the production of heat. This raises the temperature of the battery and it may feel warm or even hot to the touch after the engine has run for some time.

5. Swollen Batteries

An abnormally charged battery has lots of hydrogen gas accumulating in it and if there are no vents for this gas to escape where the battery is tightly sealed, this is liable to cause the battery to swell up and hence gives its case a warped appearance.

Such batteries may in extreme cases explode with possible hazards to lives since shrapnels of metals and plastic may fly all over the place, in addition to spurts of corrosive sulphuric acid. (Read Also: How To Charge A Car Battery With A Laptop Charger)

6. Seeping Battery

Battery leakages or seeping may occur when the battery overcharges and hydrogen deposit builds up in it thereby forcing the electrolyte out through vents in the battery casing. In extreme situations, the casing may break or crack and allow the electrolyte to leak out.

What Happens When You Overcharge A Battery?

Any battery, no matter its quality, can die off when you overcharge it. When a battery is overcharged,  the sulphuric acid and distilled water mixture in it can boil over. This leads to the temperature within the battery to rise and the battery may consequently feel warm or even hot to the touch, a fact which is likely going to cause it to swell or even melt eventually.

The build-up of flammable hydrogen in the battery will cause the case to swell with leakage of electrolyte through any opening in its casing.(Read Also:Will A Bad Battery Cause Bad Gas Mileage?)

The moment this hydrogen build up mixes with oxygen, you have a sitting bomb on your hands and as a result, any small spark can ignite this mixture of flammable gases which may cause the battery to explode sending bits of plastic and metals flying all around, in addition to caustic sulphuric acid spray. This stands as the most dangerous scenario that can arise from any over-charged battery.

Can A Bad Battery Cause Overcharging?

Yes, a bad battery can cause overcharging especially where the battery refuses to retain the charges it has accumulated. That the battery fails to retain whatever charging it has received, does not stop the accumulation of flammable gases within its casing and the resultant swelling.

Though the battery wastes all the charges it has received since it is faulty, it does not stop all other conditions associated with overcharging from being played out just like it happens with normal batteries. In essence, yes, a bad battery can and do cause overcharging with the same results and possible consequences as it happens with normal batteries.

Can You Fix An Overcharged Battery?

Yes,  it is very possible to fix an overcharged battery by simply reversing the factors that caused the overcharging in the first place. However, we should note that doing this will depend on the extent of the damage the battery has suffered.

In severe cases, where the damage cannot be undone, it is best to simply replace the battery, but where possible, the entire process can be reversed by removing the cause or causes. For example, when the overcharging is caused by a faulty alternator, fixing the alternator will stop the entire influence of overcharging on the battery and it may eventually serve you perfectly.

Though to do this, the battery must not have gotten its plates and cells damaged. Furthermore, its casing must not be deformed irreversibly. If the overcharging is caused by human error such as bad jump-starting or poor connection of the wires, then effort must be made to learn how to do it correctly. (Read Also: Why Does My Car Die After I Jump Start It? Find Out Now)

When these steps are taken, the conditions associated with overcharging will ultimately dissipate and you have your battery functioning as it should. For the umpteenth time, remember that for you to be able to fix an overcharged battery, it must not have been damaged beyond where the entire process of depreciation can be reversed, otherwise, you can’t.

How Do You Wire An Alternator With An External Regulator?

In order to wire an alternator voltage regulator properly, you should start by opening the hood or bonnet of your car and promptly remove the black battery cable from the car’s battery terminal with the aid of a wrench. Thereafter, proceed to locate the voltage regulator.

From here, you should then find and isolate the multi-wired harness close to the alternator and voltage regulator. Finally, you should proceed to insert the plug into the socket which is displayed conspicuously on the voltage regulator.

This is simply how to wire an alternator with an external regulator, but while doing it, ensure to wear as much protective gear as possible and avoid handling naked wires directly as well.

Recommended Products

Though all batteries are liable to develop faults or defects eventually, some are more susceptible to this than others and that has to do with their quality and the refinement of the materials used in constructing them. For this reason, as usual, we will introduce you to items that will not give you problems unduly, because of the reputation of their manufacturers, suppliers and also the class of the materials used in producing them.

  • Optima Batteries 8020 – 164 35 Red Top Starting Battery: This battery has a reserve capacity of about 90 minutes after it has totally run down to enable you to drive around to seek help. Additionally, it is resistant to vibration and is as durable as any of its competitors, if not more so. It can also fit a wide range of vehicles, not to mention its resistance to corrosion.
  • AC Delco ACDB24R Advantage AGM Automotive BCI Group 51 Battery: Its design is perfected to guarantee unrivaled durability and resistance to vibration when driving on uneven roads,  while its calcium-alloy confers on it a corrosion-resistant grid. It is also designed to be suitable for most types of cars and trucks.
  • DB Electrical AND0525 New Alternator: It is an alternator that is very compatible with most engines that meet all OEM specifications for safety and durability. The alternator is produced using materials that not only withstand rough handling but that are also resistant to corrosion. They are supplied under terms and conditions which will protect the customers, whose satisfaction is primary at all times.

What Stops A Car Battery From Overcharging – Conclusion

We have discussed the issue of the battery overcharging as well as how to prevent it from happening. Additionally, we have discussed how to reverse the effects of overcharging in our batteries, where that is possible. Simple procedures that will enable us to identify signs of failure in batteries and alternators have been treated as they should.

The issue of jump-starting a dead battery has not been left out, in addition to a step-by-step process to get it done. In a nutshell, whatever is needed, as far as battery care and maintenance is concerned,  has been discussed in great detail. It is believed, and rightly at that, you are not likely to contend with any car battery issues that will overwhelm you after reading this article.

The car battery, the alternator, and the voltage regulator are all functionally inter-connected so much so that you may likely misdiagnose the problem of one as that of the other. However, with diligence and perseverance, it becomes easy to identify their various defects without any issues.

The need to always get this right is the major reason why the user manual was provided in the first place. Read it carefully and you stand the chance to benefit from that immensely. Where any problem is beyond you or you are confused, do not hesitate to refer such problems to specialists. Thank you for staying on throughout this invaluable journey in proper motoring.

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