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Read our frequently asked questions to find out more about batteries, chargers and inverters, solar power and wind turbines.


What does deep cycle mean?
Deep cycle means using the battery in an application that will typically discharge 60% to 70% or more of the battery capacity. An automotive battery is an SLI (starting, lighting, ignition) battery. It’s plates are designed to deliver maximum power for a short duration. Starting a car typically discharges an SLI battery only 1% to 3%. When an SLI battery is used in a deep cycle application, or in a vehicle with heavy accessory loads, the battery life will be shortened proportionally to how deeply it is cycled on a regular basis.

When should I consider a deep cycle battery?
Any time you need the battery to supply all the operating power for a vehicle or other device. Additionally, deep cycle batteries should be used in vehicles that have heavy accessory loads where the alternator cannot maintain the battery in a fully charged condition. This is typical of large bow thrusters.

How do small batteries, such as the Optima & Odyssey produce high power?
This new range of engine start batteries have been specifically designed to provide extreme high current very quickly whilst maintaining a high stable voltage. This is only possible if internal resistance is very low. This is achieved by using pure lead for plate construction. Ordinary batteries use lead-calcium alloy plates with a higher resistance that limits power output in high rate applications. Usually very large and heavy batteries – generally in excess of 100Ah are specified to compensate for this limitation.
What are “dry” and what are “liquid” batteries?
The terms “dry battery” and “liquid battery” are restricted to primary systems and date from the early development of galvanic elements. At that time, a liquid cell consisted of an electrolyte-filled glass container into which electrochemically active electrodes were immersed. It was only later that unspillable cells which could be used in any position and had a completely different construction were introduced, these being similar to today’s primary batteries. These earlier cells were based on paste electrolytes. At that time they were known as dry batteries. In this sense today’s primary batteries are also dry batteries.

The term “liquid battery” is in principle still applicable to certain modern secondary batteries. For large stationary lead-acid or solar batteries, liquid sulfuric acid is preferred for the electrolyte. For mobile applications unspillable, maintenance-free lead-acid batteries are recommended and have been available for many years. Their sulfuric acid is immobilized by a gel (or a special microglass mat).

Are leak-proof semi-traction batteries available?
Yes, AGM and Gel batteries are readily available and becoming more popular due their ease of use and non-hazardous nature.

What type of charger should I buy?
An automatic charger offers the greatest convenience. Just plug the battery into the charger and the charger does the rest. Manual chargers, although equally effective at charging batteries, require a greater level of attention. Generally speaking, automatic chargers are priced higher than manual chargers.

Do you ever add acid to a battery?
Under normal operating conditions, you never need to add acid. Only distilled, deionized or approved water should be added to achieve the recommended level. When a battery is shipped in a dry state or accidental spillage occurs, electrolyte should be added to the battery. Once filled, a battery should only need periodic water addition.

What are common mistakes made by lead acid battery owners?
Undercharging: Generally caused by not allowing the charger to restore the battery to full state of charge after use. Continually operating the battery in a partial state of charge, or storing the battery in a discharged state, results in the formation of lead sulphate compounds on the plates. This condition is known as sulphation. Both of these conditions reduce the battery’s performance and may cause premature battery failure. Undercharging will also cause stratification.

Overcharging: Continuous charging causes accelerated corrosion of the positive plates, excessive water consumption, and in some cases, damaging temperatures within a lead acid battery. Deep cycle batteries should be charged after each discharge of more than 50% of the batteries rated capacity, and/or after prolonged storage of 30 days or more.


Can my charger be used with lead acid and gel batteries?
Possibly. Some chargers can be adjusted manually to recharge either conventional Lead acid or sealed Gel batteries. This is usually done by means of an output adjustment screw or toggle switches. If your charger is not suitable the batteries will fail prematurely. If you are in any doubt you should contact the charger manufacturers.

Can a standard car charger be used with my batteries?
If you are recharging a car or van the answer is yes. If you want to recharge large commercial batteries you must ensure the charger output is sufficiently high enough before charging commences. If you are charging deep cycle or traction batteries the answer is no. Deep cycle and traction wet lead acid batteries require a higher charging voltage and charge current than the average automotive charger can produce.

How long will it take my batteries to fully recharge?
The amount of time it takes a battery to charge depends on the type of battery and charger and on how long it took to discharge (slow or fast). As a rule of thumb you can divide the battery capacity by the maximum charge capacity and add four hours. The four hours is for the so-called after-charging time, where the battery determines how much more current it needs to get back to a fully charged state. For example, an empty 200 Ah battery connected to a 40A battery charger would take about 200 divided by 40 = 5 + 4 hours to charge, 9 hours in total. If the battery had been only 50% discharged the calculation would be: 100 divided by 40 = 2 + 4 hours, 6 hours in total.

When do I need to perform an equalization charge?
Equalizing should only be performed on vented wet lead acid batteries. How often this might occur with your battery will vary depending on your application. You will need to monitor your battery voltage and specific gravity to determine when equalization is needed. For example, it is time to equalize if the measured specific gravity values are below manufacturer’s recommended values after charging (recommended value for Trojan Deep Cycle batteries is 1.277 +/- .007 at 80o F). Equalizing is also required if the specific gravity value of any individual cell varies 30 points or more. Reduced performance can also be an indicator that equalizing is necessary. Equalization should also be performed when individual battery voltages in a battery pack range greater than 0.15 volts for 6 volt batteries or 0.30 volts for 12 volt batteries. A good rule of thumb is to perform equalize charging once every 10 cycles.

What type of charger should I buy?
An automatic charger offers the greatest convenience. Just plug the battery into the charger and the charger does the rest. Manual chargers, although equally effective at charging batteries, require a greater level of attention.

What size charger should I buy?
A properly sized charger takes into account battery capacity and the time interval between charges. In applications where cycling is infrequent, such as weekend users, or infrequent or seasonal usage, a charger with an output current rating between 10 and 13% of the battery’s rated 20-hour capacity will suffice. In applications where battery recharge must be accomplished within 8 to 10 hours, a three stage, automatic charger, rated at 20% of the battery capacity, may be required.


Can I use my inverter in parallel with the generator or shore power?
Definitely not! If you have a generator on board or a shore connection you must

install a Masterswitch. The switch is available with various applications, but

its main function is to switch automatically and safely between shore,

generator and inverter power.

Can I run a computer on the inverter?

Yes, you can. All Victron pure sine wave inverters can easily and safely supply

a computer. In fact the output voltage from an inverter is often better than

that from the electricity grid. A Victron inverter, combined with a battery

charger and a battery set, is often used as a back-up system on shore in places

where the grid connection voltage is contaminated or unreliable.

Can I run a microwave on an inverter?

Yes. You can connect any model of microwave to your inverter, but keep in mind

that an 800 watt microwave consumes 1200 to 1300 watt from the 230V system, so

you must make sure you choose the correct size inverter.

How much battery capacity do I need with an inverter?

As a rule of thumb you can assume the minimum battery capacity for a 12V

installation is about 20% of the inverter capacity. For a 24V installation this

would be 10%. In other words the minimum battery capacity for a 1000W inverter

is 200Ah at 12V or 100Ah at 24V.

Are there any appliances that cannot be run on an inverter?

In general you can connect almost any appliance to an inverter, with a few

practical exceptions. While the inverter can easily supply a heavy load like an

electric heater, the battery capacity is often too low to maintain the supply

for any great length of time. The same applies to air conditioning units. As

long as the battery capacity is high enough you can use a large inverter to run

a washing machine, a large single cooking element or a small two-ring electric


How much power does an inverter consume?

If you connect a 850W coffee machine to an inverter, consumption will be 850W

divided by the voltage of the electrical system (12V) = 70 Amperes. Add another

8% (100%-92% =8%) to this total for the inverter consumption. The total power

consumption is then 70 Amperes + 6 Amperes = 76 Amperes. Of course a coffee

machine is only in use for about 10 minutes so the actual Ampere consumption is

relatively low (76 x 10 min = 13Ah).

Solar Power:

How does solar equipment work?
Photovoltaic (PV) Solar panels turn day and sunlight into electricity. The absorption of light in the solar cells builds up electric voltage (volts), as solar cells do not store any electricity all energy gained is fed through a regulator to the battery and stored there.

How long do solar modules last?
Life expectancy is around 20 years depending on the type. All parts are designed for outside use, even seawater, hail and storms can’t damage our Solar panels.

Do solar panels need maintenance?
The only maintenance a solar panel requires is cleaning with a damp cloth from time to time, no other maintenance is needed. However, if lead acid batteries are used the acid levels need to be checked every six months and topped up if necessary.

How do I measure the size of equipment required?
Quite simply: to work out your average consumption per day: Find out the specified power of an appliance (watts) and multiply it by the daily running hours.

For example:




Running time

per day


per day


5 watts

5 hrs

25 Wh/d


10 watts

4 hrs

40 Wh/d

Colour TV

40 watts

3 hrs



55 Watts

12 hrs


Are blocking diodes fitted in the solar panels?
No, all Solara and Victron solar panels require regulators fitted in the system for complete protection.

Wind turbines:

Are wind turbines noisey?
The “swish” sound of the rotor blades passing the tower of a wind turbine primarily arises at the tip and the back edge of the rotor blade. The higher the rotational speed, the louder the sound.

Aerodynamic noise has been cut dramatically during the past ten years due to better design of rotor blades (particularly blade tips and back edges), as a consequence the new Air Breeze has been found to emit the same sound levels as background sounds (wind and surrounding ambient noises) in third party testing.

Is wind energy expensive?
No. Wind energy has become the least expensive renewable energy technology in existence.

Is wind energy environmentally safe?
Yes. Wind energy leaves no harmful emissions or residue in the environment.

Are wind turbines reliable?

Wind turbines only produce energy when the wind is blowing, and energy production varies with each gust of wind. The variable forces acting on a wind turbine throughout its average lifetime of 120,000 operating hours could be expected to exert significant wear and tear on the machine. Turbines therefore have to be built to very exacting industrial standards. High quality modern wind turbines have an availability factor above 98 per cent, i.e. the turbines are on average operational and ready to run for more than 98 per cent of the hours of the year. Modern wind turbines only require a maintenance check every six months.

Will wind energy work on a small scale?
Wind energy can be used in all sorts of applications – from small battery chargers in lighthouses or remote dwellings to industrial scale turbines of 1.5 megawatts capable of supplying the equivalent of the electricity consumption of one thousand families. Other interesting and highly economic applications include wind energy used in combination with diesel powered backup generators in several small, isolated electrical grids throughout the world.