Now’s the perfect time for checking all your batteries as well as an external equalising charge.

Frequent short trips in distribution transport, irregular driving profiles in combination with stop-and-go traffic, daily cold starts (in icy temperatures during harsh winters), additional electrical consumers in the long-haul truck such as seat heaters, auxiliary heaters, air conditioners or refrigerators have lowered the energy level of your batteries start by start, trip by trip and break by break. Treat your batteries to an extra portion of external recharging now. 

At the latest always coordinate with the tyre change in spring or late autumn.

This is how to do it properly.

Now you can get even more power out of your HGV batteries.

The following Banner battery tips will show you how to make the best use of electrical consumers when being used in a motor home and during longer periods of non-use, since an engine that is switched poses a real challenge for the batteries. Also note the tips on extending battery life while driving, the need for external periodic recharging and the special notes on cold starting.

HGV batteries discharge much more often than car batteries. This means special care must be taken in this case to charge the batteries externally about every 3 weeks. If this is neglected, the open-circuit voltage of the batteries can drop from 25.44 V to 24.6 V or even less – which only results in negative consequences. We are therefore dealing here with a 24V vehicle electrical system in which at least two 12V batteries are connected in series.

Banner tip: A 225 Ah battery that is 50% discharged requires approx. 6 hours to be fully recharged using a 25 A charger (Accucharger PRO 25A), a battery that is 30% discharged approx. 3 hours.

1. Checking the electrolyte level

Before charging, check the electrolyte level and, if necessary, fill with desalinated or distilled water to the max. acid residue mark or 15 mm above the upper edge of the plate. The screw connections of the batteries must not remain open during charging. It is best to close them again.

AGM technology: AGM batteries should not be opened. It is not possible or necessary to measure the acid density or top up with distilled water.

2. Active and mobile

Inactive batteries discharge. Lead sulphate is deposited on the lead plates and hinders the flow of the current. The battery capacity and the cold start performance decreases. A charger, such as the Banner Accucharger 10A/24V or Accucharger PRO 25A, keeps the batteries active and prevents acid stratification or resulting sulphation. A main cause of acid stratification is short-distance driving with simultaneous use of many additional electrical consumers. The generator (alternator) no longer has enough time to fully charge the batteries.

Batterietipps - Extraladung

3. Keeping an eye on the charge level

The display shows the charge level and the current power consumption and alerts the driver if the charge level is too low, for example. Today, a long-distance lorry is more than just a means of transporting goods from A to B. It’s the trucker’s place of work (keyword office) as well as their home (keyword kitchen, living room/bedroom), often for 5 days a week or more.

Batterietipps - Sicher durch den Winter

4. Safety during winter

A drop in temperature from +20 to –18 °C reduces the available battery capacity in Ah by approx. 50%.

Banner tip for continued sufficient starting and on-board power: therefore, always pay attention to the battery charge level and moderate use of additional electrical consumers when the vehicle is not in use.

5. Switch off electrical consumers

When the engine is switched off, only battery power is consumed (for refrigerator/tablet computer/audio system/other additional consumers). Use electrical consumers with caution – especially when idling for long periods of time.

6. Suitable vehicle mode

If you’re not actively using the cab functions, you should always activate parking mode.

If you use the cab functions, switch to living mode. However, remember to switch straight back to parking mode afterwards. Additional cab functions are available in accessory mode. Use this mode with caution and only for a limited time so that the battery power is not completely used up. Be sure to switch off unnecessary power consumers.

Do you know what the biggest power consumers in your HGV are?

If you use the refrigerator, air conditioner, lighting and entertainment for 10 hours, they consume up to 170 Ah. Since a battery with 225 Ah can only deliver about 50% of its energy before its life expectancy decreases, this could discharge the battery to the point that the HGV comes to a halt and has problems starting.

This consumes about 1-3 Ah (and even more when the outside temperatures are higher). If it remains switched on over the weekend, it discharges a fully charged battery by more than 50%. If the battery was not fully charged, it will be deeply discharged by the fridge’s power consumption.

Air conditioning
This consumes  approx. 10-30 Ah and switches off when the charge level of the battery reaches 45%. At +30 °C outside temperature, you can use it for 8-10 hours if you set the cab temperature to +26 °C. At a desired temperature of +20 °C, this time is reduced to approx. 4-5 hours. Always choose an inside temperature that is similar to the outside temperature.

Lighting and entertainment
They are all large consumers of electricity. The interior lighting consumes about 5 Ah. And if you connect your TV and audio system to the AUX connection or use your laptop, you’ll consume about another 4-5 Ah.


Auxiliary heating

This has an energy requirement of approx. 4-10 Ah and is often the biggest consumer of electricity in winter. As this is used at low temperatures, please note that the battery power is significantly reduced. At an outside temperature of -18 °C, for example, the battery capacity is reduced to only about 50%.


Testing commercial vehicle batteries

How to do it properly with the Banner BBT HD1+ battery tester


With the Banner test and checking devices, you can check charging states, functionalities and much more. Simple, safe, reliable and fast, and – with test report. It’s the perfect tool for Banner sales partners and commercial end users such as fleet operators, freighters and forwarding agents.  


An acid density measurement with an acid tester (hydrometer) is primarily recommended if no Banner charger of the Accucharger or Accucharger PRO series is used. Banner automatic chargers carry out the charging process fully automatically. The optimum charging voltage is always correctly timed slightly above the gassing voltage. Thus, electrolyte mixing is guaranteed and the risk of acid stratification in the battery is reduced to a minimum.  

Banner tip: How do you recognise an acid-stratified battery? The open-circuit voltage is high and does not match the acid density. As a rule of thumb, the open-circuit voltage is the density of the acid + 0.84. For an acid density of 1.26, a cell therefore supplies 1.26 + 0.84 = 2.1 V. This 12 V battery therefore has an open-circuit voltage of approx. 12.6 V.

Please note: When checking the charging voltage in the vehicle, you must also check the individual voltage of each battery. We recommend that you periodically check the open-circuit voltage of each individual battery using the Banner Battery Tester BBT DBA 12V


This is a handy meter that quickly and reliably measures the battery voltage. Super easy application with high precision. Please make sure to recharge the battery as soon as an open-circuit voltage limit of 12.5 V has been reached. To be able to measure the off-load voltage, you should wait approx. 5 hours after you have finished charging the battery (internally by alternator, externally by charger), or it has not been discharged for at least 1 hour.

Recharging batteries

Two clever accessories


Some transport journeys are particularly demanding. You may suddenly need more power from the batteries than planned. Good to know! In many urban centres, it is often not permitted to leave the engine running when stationary for environmental reasons, so that the batteries cannot be charged via the alternator (generator). This where Banner chargers make themselves useful.

Depending on the capacity of the batteries or charge level, we recommend the following charger, and all come with a charge retention function:


  • Batteries up to 240 Ah, often equalising charge with an open-circuit voltage of the individual battery >12.5 V
    Banner Accucharger 24V 10A Recovery

  • Batteries up to 240 Ah, mostly recharging with an open circuit voltage of the individual battery <12.5 V
    Banner Accucharger PRO 25A
    NEW: Now with special 16 V refresh mode for deeply discharged batteries.

Charging for battery systems

Series circuit 24 V electrical system


For a series circuit add together the voltages of the individual batteries. Two 12 V batteries must be connected in series in order to implement a 24 V electrical system power supply.


Please note:

  • Both batteries must have the same type designation.
  • Both batteries must be around the same age.
  • Both batteries must have the same state of charge.
  • The connecting cables must be of the right size and be kept as short as possible.
  • Always change both batteries.

If the above-mentioned recommendations are not observed, a series circuit will result in a corresponding division of the voltage due to the different internal resistances of the individual batteries and thus in an asymmetrical (= unbalanced) load during the charging and discharging phase.

If an asymmetry (= unbalance) is unavoidable (due to different temperatures at the batteries or 12 V partial loads) we recommend the use of the Charging Equalizer. This adjusts the charging voltage on the batteries evenly.

Giving a jump start

A Banner booster will certainly help if the HGV isn’t showing signs of life.


What to do when things go wrong? Banner boosters supply mobile power at any time and at any place. The portable jump starters can be used quickly and are not complicated to use. Maximum power, the high-quality design, the solid housing and technical details – such as reverse polarity protection, or the fully insulated brass crocodile clips with practical LED work light – impress every professional even in the toughest situations.

Banner tip

For battery systems with two or more batteries, always replace both or all of the batteries, or at least also remove the battery/batteries that are still good, fully charge them and install them together with the new battery. This statement applies to single battery systems (2 batteries) and double battery systems, also called dual battery systems (2 starter and 2 on-board batteries each).

Single battery system: The starter (starter motor) and the on-board components access the same set of batteries.

Dual battery system: The starter (starter) and the on-board components access 2 different battery sets. This dual battery system is recommended for long-distance trucks with the highest energy requirements (power consumption). 


If possible, do not use external voltage converters (inverters). The voltage transformer consumes a quiescent current of 1-2 Ah even when no device is connected! If it is not possible to do without it, please be sure to disconnect the voltage transformer immediately after using it. Inverters automatically convert 12V or 24V direct current into 230V alternating current and supply laptop, compact kitchen units with coffee maker and microwave to TV, hi-fi entertainment equipment and other electrical appliances with alternating current.

Leading commercial vehicle manufacturers already rely on the best Banner batteries from the Buffalo Bull series as their original equipment. BOMAG soil compactors, Caterpillar excavators, Kässbohrer Pistenbully snow groomers, Kubota agricultural and construction machinery, Liebherr construction machinery, Lindner tractors, Mercedes lorries, Rammax construction machinery and Wacker Neuson excavators.
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