In most cases, after buying a new battery, motorists forget for a long time about such a problem as unsuccessful morning engine starts. But it also happens that a completely new battery is discharged to zero on the second day of operation. In such situations, many sin against sellers, however, this is far from the only possible reason for such a development of events.

The new battery is discharged: 10 reasons

If the new battery is dead, do not get hung up on the fact that you slipped substandard in the store. As practice shows, this is only one of nine common reasons. And all the rest are no less likely. Therefore, before you return, try to find out why the new battery is dead in your case.

Here is a short list of possible causes that need to be systematically checked and ruled out (or confirmed):

  1. In fact, I got a factory marriage.
  2. The battery is actually not brand new.
  3. The battery was not serviced by the seller.
  4. You have chosen the wrong model.
  5. The battery was not charged before being installed on the vehicle.
  6. The machine has a large leakage current.
  7. The battery does not have time to recover from the generator.
  8. The car was parked for a long time.
  9. Generator defective.
  10. Problematic starter.

If this list is enough for you to understand what the problem is and why the new battery is dead, it's already good. If questions remain on some points, further explanations are given for each of the reasons given. Including, it is told how this reason affects the battery, and how to exclude it , or vice versa, confirm it. In addition, understanding this topic sometimes leads to the conclusion that there was no need to purchase a new battery. Even the old one would look like.

Manufacturing defects

This is perhaps the most unlikely reason why a new battery died. Today, competition between sellers and manufacturers is very high. Some carefully monitor what they put on the market, others - what they sell to people. Nevertheless, despite all this, marriage should not be completely ruled out.

A defective new battery is rare, but it still happens
A defective new battery is rare, but it still happens

It's not that hard to calculate it. First, the battery must be checked before being installed on a car using a load plug. Marriage will immediately manifest itself in the form of a wild voltage drop under load and a weak starting current. Secondly, any self-respecting motorist will never put a new battery on the car without first charging it from a stationary charger. By the charge time, you can easily understand whether the battery is defective or not (although this is for experienced users).

Fortunately, all batteries sold today are covered by a vendor warranty that takes effect on the day of purchase. If you manage to prove that you were sold the marriage, you must either return the money spent or offer a similar replacement. In order to receive a refund under the warranty, the battery must remain presentable and fail the load plug test.

New battery not brand new

If you bought a battery in a store, then this is not at all a guarantee that it is new. Before the products get into the hands of users, they gather dust on the shelves or in warehouses for a long time, which is natural. It doesn't get any better than that, unfortunately. Moreover, the release date of the battery may be indicated somewhere in the warranty card or as a sticker on the case. Remember once and for all - this is a fake. The true production date of the battery is stamped right on the case so that it is almost impossible to fake it.

If the battery is sold in a store, this does not mean that it is 100% new
If the battery is sold in a store, this does not mean that it is 100% new

However, there are certain difficulties here as well. The fact is that battery manufacturers do not stuff dates on their products in the same format that an ordinary person is used to. They are encrypted in a long digital code, which can only be deciphered using special tables. They are freely available on the Internet. Moreover, both for already past dates, and for future ones. It is highly desirable to study this issue before buying, so as not to buy some junk.

Now for the novelty. Which battery can be considered new - made “yesterday”, or one that is a couple of years old. A few years ago, it was necessary to focus on one year. That is, if the battery is less than a year old, then it was considered completely new. Today, this period has exactly doubled. That is, a two-year-old battery, provided that the seller took care of it (more on this below), can be considered new.

More experienced motorists do not trust either the first indicator, much less the second. They are looking for batteries that are no more than three months old. It is this option that is considered the best, if only because it allows you not to rely on the good faith of the seller who stored the battery. Finding such a “fresh” option, and even in the desired price category, is not very easy. But, as a rule, if you focus on budget models of well-known brands, then they fly like hot cakes. That is, they are updated on the shelves regularly. Accordingly, finding something fresher is not particularly difficult.

Unserviced battery

Absolutely every seller involved in the sale of batteries is obliged to regularly service the products stored with him. The battery is a product that constantly requires attention. If the battery just stands somewhere in a warehouse or in a shop window, then it must be recharged at least once a month from a stationary charger. If this is not done, the battery will die due to self-discharge, and already in the store, an irreversible sulfation process will begin in it. The battery will begin to lose capacity and maximum starting current.

Recharging new batteries is the responsibility of the seller
Recharging new batteries is the responsibility of the seller

Unfortunately, it is not always possible to check whether a particular seller serves their batteries. But, for example, if you were sold a battery in an intact polyethylene package, then obviously no one has ever serviced it. Again, if the battery is a month or two old by the date on the case, then there is nothing catastrophic in this. If you bought not the freshest version, packed in a factory film, problems are guaranteed.

The wrong model

This reason should be considered, rather, as a myth, and not as a really possible one. For example, your car had a 75 amp-hour battery before the replacement. You bought a new one, but already at 65 ampere-hours. Could this be causing the new battery to run out of power? Of course not. Such a difference in capacity will not manifest itself in any way. Especially since it's so critical. Well, as for the maximum starting current, any modern battery has it with a huge margin. In this direction, there is nothing to think about.

There is a separate article about choosing a new battery for a car
There is a separate article about choosing a new battery for a car

Much more often, batteries are incorrectly selected according to the size or location of the terminals. But, as you understand, these parameters cannot affect the accelerated discharge in any way. And in general, if you didn’t manage to buy a battery from a truck or a moped for your car, there are no reasons to sin on this point at all.

The battery was not charged before installation on the car

This cause is more common than the others described here. The car owner, counting on the fact that the new battery is fully charged out of the box, installs it immediately after purchase. You should not do this under any circumstances, even if the seller assured you that he regularly recharges the batteries he sells.

Installed a new battery on the car - recharge it
Installed a new battery on the car - recharge it

Before installing on the car, a new battery must be charged from a stationary charger. Regardless of what technology it is made of - Ca/Ca, GEL, AGM or any other. In addition, if the battery is with liquid electrolyte, and there is direct access to it, you need to check the level and density with a hydrometer (hydrometer vs refractometer). So you prepare the battery for operation, and you can also identify defects in advance, if any.

By the way, you can check how much the new battery is charged “out of the box” by the voltage at its terminals. If the measurements show 12.7 volts (no load), then the battery is fully charged. If it's less, you need to recharge it. Keep in mind that after installing and connecting the battery to the car's on-board network, the degree of charge can no longer be determined by voltage. The battery will immediately be under load (leakage current, devices in standby mode), and the voltage will be slightly lower.

Large leakage current

High leakage current will quickly discharge even a new battery
High leakage current will quickly discharge even a new battery

Normal leakage current should not exceed 0.08 amps. If it turned out to be higher on your car, it is likely that this was the reason for the rapid discharge of the new battery. Checking the leakage current is very easy. To do this, any multimeter is taken, included in the current measurement mode in the range up to 10 amperes, and connected to the break in the on-board network. That is, one (any) terminal is removed from the battery, then one multimeter probe is connected to the battery, and the second to the removed terminal. After a few seconds (until all electronics go into standby mode) the instrument will show the true leakage current on your machine.

The battery does not have time to recover from the generator

This happens when the car is used for short trips. If you drive less than half an hour a day, or use the starter frequently, the battery will not have time to recover. In addition, the normal charge of the battery from the generator is affected by the voltage of the on-board network when the engine is running. If it is less than 14.4 volts, the battery will never be charged at 100%, no matter how much you drive in time.

In addition to common causes, a new battery can be discharged due to alternator malfunctions
In addition to common causes, a new battery can be discharged due to alternator malfunctions

Separately, it should be said about winter operation. When the temperature is negative outside, the battery from the generator is not restored at all for the first 20-30 minutes. It starts to take charge from the generator only after warming up.

Long term parking

To prevent the new battery from being discharged, remove the terminal during a long stop
To prevent the new battery from being discharged, remove the terminal during a long stop

Here, perhaps, everything is already very clear. If the machine has been left unused for a long time, even a new battery will be discharged. The larger the leakage current, the faster. Ambient temperature also greatly affects the rate of discharge of the battery when the car is stationary. If it's cold outside, the battery can freeze in the literal sense of the word much earlier than if it were summer. And all due to the fact that as the discharge decreases, the density of the electrolyte decreases, and its freezing temperature rises.

Faulty generator

In order for the new battery not to be discharged after the first day of operation, it must be recharged from the generator. If this node is faulty, or does not work out completely, in the morning the battery will most likely fail. Again, be aware of the time you give the battery to regenerate power from the generator. Air temperature and on-board network voltage also play an important role in this.

Checking the generator is very simple. If, while the engine is running without electrical appliances turned on, the voltage of the on-board network is kept at 14.4 volts and above, then this is the norm. If it is lower, then the generator or relay-regulator is faulty, and they will not be able to fully charge the battery. It is important to measure the voltage of the on-board network not anywhere (in the cigarette lighter, for example), but directly at the battery terminals. Accordingly, it is pointless to blindly focus on a regular voltmeter, which is in any modern car. Unless, of course, it was properly calibrated the day before.

Replacing generator slip rings.

Problem starter

A defective or unserviceable starter often causes a new battery to discharge
A defective or unserviceable starter often causes a new battery to discharge

The car starter is the most voracious consumer of the on-board network, even if it is fully serviceable and well maintained. If it turns tightly due to breakdowns or clogging, or takes on a lot of current, wedges, and so on, even a new battery will be discharged very quickly. In some especially neglected cases, the starter during operation generally gives a load on the battery, commensurate in current strength with a short circuit. It is clear that even a new battery can be discharged under such conditions.

Brief summary

If a new battery is discharged in the first days of operation, there may be several reasons for this. It is not at all necessary that you slipped a marriage in the store, or you bought frank Chinese rubbish. The new battery could have been unserviced by the seller, not recharged by you, and so on. There are many problems with the car itself. As a rule, the probable causes described in the article are enough in 95% of cases to find out why a new battery has run out.

VIDEO: about car battery draining