How to fill the battery with distilled water

Everything you need to know about batteries

Date coding of batteries for inventory turnover

A -storage

  1. You should constantly change your inventory and use the FIFO (First In, First Out) procedure. Batteries lose their charge slowly - good inventory turnover prevents batteries from discharging during storage and ensures that the customer purchases a battery in good condition. On the back of the battery you will find a label with the estimated time it will be used before the battery needs to be charged. This allows you to easily distinguish the oldest from the newest batteries in stock. Please use the recharge date as a guide to ensure that the oldest batteries leave the warehouse first. The charging date is only an indication of the time of charging, the self-discharge depends on the storage conditions.
  2. Store batteries in a cool, dry, well-ventilated place.
  3. Protect batteries from excessive heat. (Batteries discharge faster in heat and excessive heat can damage the batteries).
  4. Store batteries in an upright position. (This prevents the batteries from tipping over or leaking).
  5. Do not stack batteries on top of each other. (This avoids scratches and torn labels, as well as damage to the terminals that protrude from the battery cover).
  6. Up to three shrink-wrapped batteries can be stored on top of each other. (Stacking more batteries on top of each other increases the risk that they will tip over and injure people).
  7. Do not remove seals from dry-charged batteries before using them if they are being filled with acid. (The seal maintains the charge in the battery. If the seal is broken, air will penetrate and the battery will discharge).
  8. Batteries are stored on shelves or pallets, not on the floor. (Small stones or sharp edges on a concrete floor can damage the bottom of the battery and cause leakage).
  9. Make sure the handles are in a flat (upright) position. Upright handles are more easily damaged.

B -Care of stock itemsand charging batteries

WET charged batteries

1. Batteries should ideally be installed within 15 months of manufacture. The voltage at the time of installation should ideally be above 12.4 V (in the worst case above 12.25 V).

2. If the voltage drops below 12.4 V due to long storage, the batteries need to be charged. All necessary safety precautions must be taken before charging batteries. Refer to the Loading Instructions section in the catalog for more information. When the battery has been charged, the charging date on the label on the back of the battery should be indented 6 months after the second charging date. (Please note that a maximum of two top-ups are allowed before sale and that the product must be sold a maximum of 9 months after the first recommended top-up date).

2.1 Voltage measurements should of course be made both to identify older inventory and to mark batteries that need to be charged.

2.2 Use a digital voltmeter / multimeter that shows at least two digits (e.g. 12.76 V).

2.3 Sort out all batteries with less than 11.0V (these batteries have had sulfation that cannot be completely reversed by charging, so the battery cannot provide the performance and service life expected by the customer)

2.4 Please note that digital conductance testers (such as Midtronics and / or Bosch BAT121):

  • NOT suitable for testing batteries.
  • Digital battery testers are not designed to test the fully developed cold start capability of a new battery.
  • They are only suitable for testing and assessing defective or used batteries.
  • All measured values ​​for the CCA / health status of a new battery do NOT allow any reliable statement to be made about the battery specification.

See comments on digital conductance testers.

DRY charged batteries: inventory maintenance

The sale of dry-charged batteries within our range is very limited, usually concentrated in specialist stores and is therefore not included in this catalog.

  1. If you store dry-charged batteries in a cool, dry place and do not remove the seal, no further maintenance is required.
  2. The maximum storage time for dry-charged batteries before they are filled with acid and used is 24 months.
  3. If the seal has been damaged, the battery should be filled immediately and then treated like a WET battery.
  1. Do not fill a dry-charged battery until it is needed for a customer.
  2. Remove all plugs, adhesive tapes or foils from installed batteries.
  3. If the batteries are installed, remove and retain the normal valve plugs and terminal covers (usually red and black).
  4. Use diluted battery-grade sulfuric acid with a density of 1.270 - 1.280 at 25 ° C, in accordance with BS3031 or better, for filling. (Note: Acid contaminated with impurities can severely shorten the life of the battery, in some cases as little as a few days. Do not use acid from old batteries).
  5. The temperature of the acid and the battery should be between 15-30 ° C at room temperature.
  6. Fill each cell with acid to a level 3–6 mm above the top of the separators. Fill one cell at a time and complete the process in one go.
  7. Let the battery rest for 20-30 minutes and then measure the open circuit voltage. If it is below 12.50V, charge the battery. (See Section G). If it is above 12.50V, adjust the acid levels with dilute sulfuric acid with a density of 1.270 - 1.280 to the correct usage level. See Section D.
  8. Install the normal valve plugs and terminal covers.
  9. Wash the battery with hot water and let it dry.
  10. Please note that it is not advisable to test newly used, dry-charged batteries with electronic digital testers using conductivity technology (e.g. with testers from Midtronics or Bosch). The results can be misleading if the battery has not been used for some time.

D -Electrolyte levels (acid levels) in operation

Notes: Please read this section before adjusting battery acid levels.

  • Do not fill a battery that needs charging to the maximum level. (The level rises while charging). However, if the stands are below the tops of the separators, fill them with distilled or deionized water until the separators are just covered.
  • You can fill up to the maximum level at least one hour after charging the battery.
  • Do not overfill a battery. (The acid could leak from the vent plugs during the charge).
  • Only fill the battery with distilled or deionized water. (Sulfuric acid should only be used when the battery is filled for the first time). Do not use bottled mineral water (the impurities in the water increase water loss and self-discharge of the battery).
  1. When the battery is installed, the electrolyte levels should be checked and adjusted to the levels noted above.
  2. If there is a maximum level mark on the side of the battery compartment, fill the battery to this maximum level.
  3. If there is no mark but filling hoses protrude from the bottom of the lid, fill the hoses to the bottom.
  4. If there are neither markings nor filling hoses on polypropylene batteries, fill up to 7 mm below the lower edge of the lower part of the lid.
  5. If there are no filling hoses on hard rubber batteries, fill them up to 15 mm above the top of the separators.

E -Select the correct battery for the application

Batteries for cars and commercial vehicles (CV batteries)

  1. Select the default battery in the application section of this catalog.
  2. With 24-volt systems or when two 12-volt batteries are installed in parallel, both batteries should be replaced at the same time. Failure to do this will greatly reduce the life of the newly installed battery. When batteries are installed in series, the negative terminal of one battery is connected to the positive terminal of the other battery to achieve a total voltage of 24 volts. The capacity of this system in ampere hours corresponds to that of single batteries. When batteries are installed in parallel, the positive poles of the two batteries are connected to each other, just like the negative poles of the two batteries. The voltage of the system remains unchanged at 12 volts, but the capacity in ampere hours is twice as large as that of individual batteries.

Leisure batteries

  1. Choose the battery that the equipment supplier recommends for power and size.
  2. We recommend, Leisure batteries in medium cyclical application so that they are discharged to a maximum of 50% charge level. This ensures a good service life for the battery. The life of a battery that is regularly discharged 50 percent is approximately five times longer than the life of a battery that is regularly discharged to 100 percent. Example: 10 hours of 4 A load current discharges the battery by 40 Ah. If this corresponds to a charge level of 50 percent, we recommend an 80Ah battery.

Marine batteries

  1. The product range of marine batteries was developed with a higher cycle stability than the leisure battery series and mainly for hotel loads on ships.
  2. The product range of marine batteries was developed with a sealed lid in order to exceed the 55 ° continuous requirement according to point 5.10 of EN50342.1 A1 2011.

F -Remove batteries and install batteries in vehicles

  1. It is a good idea to let the customer know that while you will do your best to preserve the storage settings, they may be lost.
  2. Make sure the handbrake is on and the car is in neutral or parked position. Turn off all electrical loads and remove the ignition key. Note: On some cars, the doors lock when the battery is disconnected, so the key should not be left in the car. Also turn off any non-factory-installed alarms.
  3. Make sure the cigarette lighter is still working. If not, turn the ignition key to the auxiliary position. Install a Computer Memory Saver (CMS).
  4. First disconnect the earth connection. (In modern vehicles this is usually the negative pole). This can cause memory settings to be lost; please refer to the vehicle manual.
  5. Next, disconnect the positive terminal. If a CMS is used, the port will remain active after disconnection. To prevent short-circuiting the connector, place an insulator, such as a rubber glove, over the connector.
  6. Remove the hold-downs.

Preparing a battery for installation

  1. Make sure the battery has the correct polarity for the vehicle.
  2. Make sure the battery is the correct height for the vehicle. (If the battery is too high, it could short out the hood, the underside of a seat, or damage the hood).
  3. It is advisable to place the old and the new battery next to one another in order to compare the polarities, hold-down devices and power levels. Some batteries have hold-downs on both sides and ends. You only need to check those necessary to secure the battery in the vehicle.
  4. Make sure the battery is clean and dry.
  5. Make sure the vent plugs or manifolds are firmly in place.
  6. Make sure the battery has a voltage greater than 12.40V. If not, recharge the battery or use another battery with a voltage greater than 12.40 V.
  7. Make sure that the two pole caps are still in place at this point.

Preparation of the vehicle

  1. Remove all objects from the battery holder that could damage the battery. (Placing a heavy battery on sharp gravel can puncture the bottom of the battery).
  2. Make sure that the connections, the hold-down devices and the holder are clean and free of corrosion. (Any corrosion can be permanently removed with hot water). If there is severe corrosion that could affect the stability of the battery or affect other parts of the engine compartment, have the vehicle serviced by an authorized dealer.
  3. Check that the alternator belt tension is correct. To do this, see the vehicle manual or the service instructions.
  4. We recommend checking the vehicle's electrical system, and especially the charging system, to make sure they are working properly. To do this, see the vehicle manual or the service instructions.

Installation of the battery

  1. Put the hold-downs on and tighten them. They should be tight enough that the battery is secure and won't move. DO NOT OVER TIGHTEN.
  2. First connect the positive terminal to the correct battery terminal (usually positive) after removing the pole caps. DO NOT OVER TIGHTEN.
  3. Connect the negative pole connection to the other terminal after you have removed the pole cap. DO NOT TOO TIGHTEN.
  4. Put the two pole caps on the old battery that was removed from the vehicle to avoid a short circuit.
  5. Place all components on the new battery that were removed from the old battery, for example ventilation hoses, ventilation arches, clamp covers, removable hold-down strips (widgets), etc.
  6. Vaseline does not have to be used in modern polypropylene batteries, but it does not do any harm either. Smear a thin layer on the clamps. This is still recommended for hard rubber batteries. Do not use grease.
  7. Remove the CMS.
  8. Start the engine
  9. For non-automotive applications, install the battery as recommended by the equipment supplier.

G -Charge outside the vehicle

Note: Please read these instructions before charging the batteries

  • DO NOT charge a battery if the temperature is below 3 ° C as the electrolyte may be frozen.
  • We do not recommend charging the battery in the vehicle.
  • Refer to Section F for information on how to remove the battery from the vehicle.
  • "Sealed and AGM" vehicle batteries should only be charged with constant voltage chargers or "intelligent" chargers. Do not charge them with constant current chargers or quick chargers.
  • When the vehicle batteries are closed, there is no access to the electrolyte, so they cannot be topped up. There are no removable valve plugs or manifolds. The battery can vent gases through air holes and is therefore not completely sealed.
  • A new, unused battery with a voltage below 11.00 V should be discarded and not charged. See section B.

General procedure for all types of chargers

This section gives general information on all types of chargers. The following sections provide more detailed information on the different types of chargers.

  1. Check the electrolyte levels in all cells. If they are below the top of the separators, fill them up to the top of the separators with distilled or deionized water. Do not fill them up to a higher level before charging, but adjust the levels after charging. See Section D.
  2. If you are using a constant current or rapid charger, remove the valve plugs or manifolds before charging. (See below). If you are using a constant voltage or “smart” charger, you do not need to remove the valve plugs or manifolds.
  3. Make sure the charger is turned off.
  4. When you connect the battery to the charger, connect the positive cable to the positive pole and the negative cable to the negative pole.
  5. Turn on the charger. Below you will find the correct charging conditions for your particular type of charger.
  6. Stop charging if the battery releases a lot of gas (a small amount of gas is normal in the final stages of charging) or if the battery temperature rises above 50 ° C.
  7. Turn off the charger.
  8. It is recommended that you wait about 20 minutes for the gases to evaporate before removing the cables from the battery, as some chargers can stay “active” and generate sparks.
  9. Check the electrolyte levels in all cells and top up if necessary. See Section D.
  10. If the valve plugs or manifolds have been removed, reattach them.
  11. Wash the battery with hot water and let it dry.
  12. Note: Many customers greatly underestimate the time it takes to charge an empty battery. As a result, customers will return batteries assuming they have charged the battery and it is not holding the charge.

Types of chargers and their uses

There are many different types of chargers; Below you will find their functional principles and notes on use.


sectionType of charger
1.Constant current chargers
2.Constant voltage chargers
3.Modified constant voltage chargers
4.“Smart” chargers
5.Fast chargers


These chargers deliver a fixed, constant, preset current during the entire charging period, regardless of the charging voltage of the battery. AGM batteries must not be charged with constant current chargers.

Charging process with constant current chargers

A. If possible, charge each battery with a separate charger. If this is not possible, charge batteries in series. We do not recommend charging batteries in parallel, as you cannot control how much current each battery draws.

If batteries with different states of charge are charged in series, each battery should be disconnected as soon as it is charged. (If you wait for the last battery to charge, some batteries will be overcharged).

B. Measure the open circuit voltage of the battery. To maintain stable voltage, the battery should not be inserted or charged for at least 3 hours before voltage measurement.

C. Charge the battery at the recommended rate (see the Battery Specifications section in the catalog). If you cannot set the recommended rate, extend or reduce the loading time accordingly (pro rata basis).

For example, if the battery is to be charged for 6 hours at 4.0 A (24 Ah = 4.0 x 6) as recommended, charge the battery for 12 hours if you can only set the charger to 2.0 A ( 24 Ah = 2.0 x 12).

D. Depending on the open circuit voltage, charge the battery for the duration shown in the table below.

For example, if the battery has a voltage of 12.16V, charge it for 10 hours at the recommended rate.

About 12.404
12.31 – 12.406
12.21 – 12.308
12.11 – 12.2010
12.01 – 12.1012
11.91 – 12.0014
11.81 – 11.9016
11.71 – 11.8018
11.00 – 11.7020
Under 11.00See paragraph E below

E. If you charge a battery below 11.00 V (deep discharge) that has been in operation, you may need a special charger that delivers a very high charge voltage. The recommended current may not be reached immediately. In this case, check the current and adjust it if necessary while charging.

When a battery is deeply discharged, it has lost both life and performance due to irreversible sulfation. Further charging can further reduce the useful life of the battery.


These chargers deliver a fixed, constant, preset voltage during the entire charging process. The current cannot be adjusted and decreases as the battery level increases.

Charging process for constant voltage and modified constant voltage chargers.

A. These chargers are usually designed to only charge one battery at a time.

B. Stop charging if the battery is gassing and the battery voltage has shown no increase for at least 2 hours.

C. Notice. Most constant voltage chargers cannot charge a very deeply discharged battery (below 11.0 V) in a realistic period of time. A minimum duration of
24 hours is normal.

It can happen that a deeply discharged battery can no longer be charged.


Most traditional chargers fall into this category, especially household chargers. Neither voltage nor current can be preset here.

Charging process with modified constant voltage chargers.

A. See section above for constant voltage chargers.


The latest generation of chargers can measure the battery status and automatically charge the battery as quickly as possible in a controlled manner, without damaging it and without overcharging it at the end of the charging process. Some “smart” chargers have a setting specifically for calcium batteries and will charge discharged batteries of this type, which most other chargers cannot.

Charging process with "intelligent" chargers

A. Follow the manufacturer's instructions.

B. These chargers should be able to charge deeply discharged batteries (below 11.0V). Please note that some have a setting specifically for calcium batteries.


These chargers supply the battery with a very high initial current and are mainly used to recharge a discharged battery that the customer urgently needs. As the battery level increases, the current drops and the battery temperature is monitored to prevent the battery from overheating.

Charging process with quick chargers

A. Fast charging is only recommended in exceptional situations, e.g. if the customer's car breaks down, as this charging shortens the battery life, especially if the battery is fast charged several times.

B. Rapid charging is not possible with a battery below 11.00 volts because it is too sulfated; you must discard such batteries or recharge them normally.

C. Only use quick chargers whose charging voltage is limited to a maximum of 12.4 volts and which have temperature monitoring.

D. Follow the charger manufacturer's instructions carefully.

H -Checking the battery performance

Electronic testers with conductance technology

  1. The youngest generation of testers is digital, for example the testers from Midtronics and Bosch. With these devices, you can make an instant decision about approximately 80% of the batteries running, including discharged ones. For the remaining 20%, the batteries must first be charged before testing.
  2. These testers indicate whether the battery is in good condition, charged, discharged, or needs to be replaced.
  3. Note: This is the preferred method for testing batteries because it does not remove any charge from the batteries. This method is also easier, faster, and safer.

Digital conductance testers explained in detail

Most battery manufacturers have reported confusion in the battery industry about the apparent performance of batteries after testing with digital conductance testers (Midtronics and Bosch BAT121 are the most common types on the market).

The purpose of these testers needs to be clear.

Digital conductivity battery testers are not suitable for checking the cold start capability of a new battery.

They are only suitable for testing and assessing suspect or used batteries. All readings related to CCA or health status. DO NOT allow any reliable statement about the battery specification.

The BCI and European EN standards are used as a test benchmark for the manufacturing process.

Yuasa Battery (part of GS Yuasa Corporation) is one of the world's largest manufacturers of lead-acid car batteries, and the batteries are developed in accordance with internationally recognized standards.

For example, the first performance test according to EN50342.1 A1 Nov 2011 stipulates that batteries are tested for at least 12 working days and checked with extensive material resources. All Yuasa batteries that enter the market are subject to regular audits to ensure compliance with the relevant standard.

The EN 50342 standard has created additional confusion in the market as it defines two compliance standards for high performance cold start capability that are incomprehensible to the end user without full access to the ETN list.

EN1 test @ -18 ° C 10 s at 7.5 V, 10 seconds pause, then 60% of the current at 6 V, duration longer than 73 s.
EN2 test @ -18 ° C 10 s at 7.5 V, 10 seconds pause, then 60% of the current at 6 V, duration longer than 133 s.

Battery performance obviously depends on the battery design, but a battery that is nominally 1000A according to EN1 can only be nominally 920A according to EN2. The information about the standard according to which the capacity of the battery is measured is currently contained in the ETN, e.g. 550 034 050 <

550 => 12 volt 50Ah battery

034 => A number specific to the battery that gives details on the type of lid, service life, vibration resistance and also whether the battery is rated according to EN1 or EN2

050 => high current, in this case 500 A.

Almost 2000 individual battery numbers from different battery manufacturers and users are currently listed in the ETN database. As a result, it is not clear to the customer what capacity the battery can achieve according to EN1 or EN2 without accessing the list.

Yuasa tries to counteract this confusion and is now using the long-standing American BCI SAE rating for cold start current, i.e. the current strength that can be delivered for 30 seconds at a temperature of -18 ° C to 7.2 V. This seems to us to be a more precise comparison in order to give a balanced picture of the battery life and the starting behavior.

The evolution of the conductance testers on the market

In the past decade, relatively inexpensive conductance meters have been introduced that can measure the internal resistance of a car battery using the principles of the AC Wheatstone bridge (which you may remember from your school days). The clear advantage of these devices is that they are portable and easy to use, there is no risk of sparks from drop tests at high charge rates, and results are displayed within seconds.