How To Charge A 12Volt Battery From A 24Volt System?

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Car batteries can be charged with either a connection in series or in parallel. The essential thing is to make sure that you get the connection right before you start the process. It has repeatedly been pointed out that whenever you want to charge,  you must utilize only compatible chargers.

Surprisingly, however, we are now required to charge  12V batteries with a 24V system. This is quite an anomaly, so to say, but with the adoption of some modalities or arrangements, it can be done and safely too.

Depending on the arrangement or connection in the circuit, you can effectively adjust the capacities of the batteries to conform with the specifications or ratings of the charger.

This is because,  by the arrangement of batteries in a circuit, you can either double or cut in half their voltages,  in such a way that neither the charger nor the batteries will come into any harm whatsoever.

As had previously been re-iterated repeatedly, absolute care must be taken to ensure that every connection in the circuit is done correctly without compromise. (Read Also: How To Charge Multiple Batteries With One Charger)

In order to charge a 24V battery with a 12V system, you have the option of either using a series or parallel connection. We shall discuss in detail the procedures involved in going both ways, using easily comprehensible explanations.

Table Of Contents

Charging A 12V Battery With A 24V System In Series

Step 1

In the first step, you are required to source and assemble all the tools you require to execute the procedure, which means you should get two dead 12V  batteries that you wish to charge, a 24V charger, two 12V automobile relays, some good connecting wires, distilled water, and a plier. Make sure that you perform the procedure in an open and well-ventilated place, where direct sunlight will not reflect on the tools.

Since there is a great disparity between the capacity of the charger and the voltage of the battery, in order to eliminate this discrepancy, you must use two 12V batteries instead.

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Step 2

This is the stage where you are required to perform all the connections between the battery and the charger. You should remember that absolute care must be taken here to get everything right. For charging in series, connect the positive or red charger output to the positive or red terminal of the first battery and proceed to connect the negative terminal of this same battery to the positive terminal of the second battery.

Thereafter, connect the negative terminal of the first battery to the negative power output of the charger and subsequently, the negative terminal of the first battery to the negative terminal of the second battery.

When two 12V batteries are connected like this, they generate a total of 24V which is compatible with the charger you are using.

For the series connection used here, you must equally use two 12V automobile relays, which are capable of carrying well over 100 amps for short periods and that is why they can serve as good controllers in the circuit.(Read Also:Will Jumper Cables Charge A Battery?)

The relays are operated by a third contact and are energized automatically by connecting them to the chargers. Check to make certain that your connection is correct.

Step 3

Start charging the batteries by plugging the charger into the power supply source. The charger is equipped with features that will alert you when the charge is complete. However, as in all previous cases, you are expected to closely monitor the process, in order to make sure that nothing goes wrong.


Charging 12V Battery With A 24V System In Parallel

Step 1

Just like you did previously, assemble all the tools you need to carry out the procedure: your dead car batteries, two 12V relays, the 24V charger, conducting wires, and so on.

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This is because, no sooner will you buy them than you will go back for the purchase of a similar product,  because that which you bought only recently has either packed up after a little pressure or has failed to work, for no known reason. In the end, you may end up spending twice or more the price of a similar but better model. (Read Also:Should Alternator Pulley Spin Freely?)

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Step 2

In this method of charging car batteries, the procedure is pretty much more straightforward. You simply connect the positive or red output of the charger to the positive terminal of the first battery and the positive terminal of the first battery to the same terminal of the second battery.

Likewise, proceed to do the same thing with the negative terminals too, and finally, connect the automobile relays in like manner. Generally, the fact is, when the two automobile relays are used together in the circuit, the batteries are charged in parallel,  whereas when only one or none is used, they are charged in series.

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Step 3

After checking to ensure that your connections have been correctly executed, you should then proceed with the actual charging. As always, the special provisions or features on the charger will alert you when charging is complete, although we have equally discussed other means by which you can also know when the procedure is complete. Do not forget to always keep close tabs on the process,  while it is in progress.

What Tools Do You Require For This Procedure?

The most important tools necessary in charging a 12V battery with a 24V system are the dead car batteries, the 24V battery charger, connecting wires, distilled water(in case you need to top up the electrolyte in the batteries), and a  milliammeter.

The milliammeter may be necessary where the charger is not equipped with the features that will tell you when charging is complete. In such a situation, the milliammeter will come in handy since you can use it to obtain battery readings directly.

Does This Method Of Charging Constitute Any Risks To The Battery?

Not really, provided you made your connections correctly. However, there is still the matter of the difficulty involved in getting a 24V charger, in addition to the fact that even when you are able to get it, it does not come cheap. This is not to disregard the fact that this highly-rated charger may pose a great risk to your batteries, should you connect it wrongly. This is the reason that informed the need for our repeated caution on correct connections.

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How Long Does It Take To Fully Charge A Car Battery By This Method?

The process of charging car batteries by this method is not so much different from others, even though a charger with exceptional capacity is involved This is because measures are taken to ensure that the charger does not catalyze the process unduly, which would have otherwise put the batteries to some harm. In essence, like all other methods of car battery charging, this method also takes a couple of hours to get the battery fully charged. However, the procedure can last a little bit longer than this, if the battery to be charged has been deeply drained.

How Can You Make The Process Of Charging This Way Better?

Like in all previous cases, you can make this method better by first, making sure that the batteries are not in any way compromised by checking up on the electrolyte content in their individual cells and topping up the electrolyte with distilled water, where it is a bit short.

In addition, monitor the process closely while it is in progress so that you can attend to any detrimental issues promptly if they occur. You should also wipe off grime or any dust on the battery terminals and other connecting surfaces to facilitate an unimpeded flow of electricity during charging.

Finally, you should promptly disconnect the circuit, the moment the batteries are fully charged, in order to avoid any injurious excessive charging or overheating that might damage either the battery or charger or both. These steps, if always taken, will surely improve the procedure.

Does This Procedure Compare Favorably With Others?

Certainly, it does, particularly where all the necessary precautions given are adhered to. Additionally, like all other methods of car battery charging, you can get your vehicle batteries fully revived and in good time too. This is more easily achieved where you conduct the procedure in open and well-ventilated surroundings.

How To Charge A 12Volt Battery From A 24Volt System – Conclusion

Too many factors are in play when it comes to how effectively car batteries serve us. To begin with, there is the issue of regular maintenance. We should always check out our batteries, once in a while to look out for any distortion in their appearance or bloating, as well as signs of leaking electrolytes.

Their water content should be given attention by way of topping it up with distilled water when that happens. In the same vein, we should always be on the lookout for dimming headlights or interior lights as a means of knowing when they begin to complain, which may not really be their fault, but can eventually affect them.

Similarly, car batteries must not be left in storage for too long without warming them up, for this can lead to sulfation and eventual damage. In the morning before driving out, we should allow our engines to run for a while without coercion,  to give them the chance to tune up.

Charging should be done carefully to avoid premature damage. Also, where the alternator is suspected to be at fault, prompt attention must be given, or else you risk damaging your battery. On the issue of getting new batteries, we must not cut corners by buying either counterfeit products through patronizing shoddy suppliers.

It is for this reason that we have undertaken to introduce to you reliable and highly branded suppliers and the links using which you are assured of buying the correct products. To guard against careless ruination of car batteries, we must not allow certain accessories to work when the engine is turned off, such as radios, AC, interior lights, headlights, and glass wipers. It takes little or nothing from you to do all these, but in the end, it saves you a lot.

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