In any good independent power set up, the battery is considered the 'heart' of the system. Every appliance will run through the battery, whether it is a an input charge, such as a solar panel, battery charger or vehicle, or it is an output discharge, such as your fridge, lighting or appliances; The battery controls it all.
But how to do you ensure your battery is being maintained at it's optimum condition? The answer is, a good 240 Volt battery charger can make all of the difference!
Unlike solar, or the vehicle charge, a 240 volt battery charger has the ability to penetrate a deep conditioned charge to the battery. It is one of the most reliable forms of charge to recover, maintain and prolong the condition of your battery system.
Battery chargers have come a long way in the past 10 years or so. The most common type of battery the average independent system would use these days are SLA (sealed lead acid) batteries, or Lithium LiFePO4 batteries. Both of these types of batteries are sealed and require a regulated battery charger to ensure that overcharging of the cells do not occur.
The majority of battery chargers sold on today's market are regulated / automatic. This essentially means that the battery charger will perform a number of charging stages and once complete, the charger will revert to maintaining the battery and will not allow for overcharging to occur.
But what size battery charger should you opt for?
Well, the answer to this question all comes down to charge time.
When using a sealed battery, it is good practice to stay with the 10% rule. Opting for a battery charger that is 10% of the overall capacity of the battery will allow for a charge time of approx 8 - 10 hours to completely replenished a discharged battery. (For example: A 100 AH = 10 Amp Battery Charger). This size battery charger allows the battery to recover within an overnight time, however, it does not overwork the battery and will ultimately promote long term life of the cells.
The minimum size charger you should look to use would be no smaller than 5% of the overall battery capacity (for example: 100 AH = 5 Amp Battery charger).
But what if you require a faster recharge time?
This is fine. You can choose a larger capacity battery charger. A sealed battery, such as an AGM (Absorbed Glass Matt battery) can accept UP TO one third of it's capacity as a maximum charge input. For example: A 100 AH battery can safely charge on a 30 Amp battery charger. This would be the maximum size charger you would use on this capacity battery.
Opting for a 30 Amp battery charger on a battery capacity of 100 Amps means that you can charge the battery in a little over 3 hours from completely discharged to 100% capacity again.
This scenario is not as common as many people would have an overnight stay in a Caravan park, etc. which means the 8 - 10 hour charge time is not a concern for them. But what if you're charging from a generator? You wouldn't want to run the generator for 8 - 10 hours to replenish the battery, so instead, you would look to opt for a 30 Amp charger, which would allow you to reduce the run time of your charging.
What about Lithium? How does this change my choice?
If you have a Lithium battery, then this is highly recommended to use a Lithium compatible battery charger. Many good quality Lithium batteries on the market will charge successfully from an AGM setting on a 240 Volt battery charger, however, it is true that you will never reach the optimum level of charge without a truly dedicated LiFePO4 charger.
Lithium batteries can accept a much higher input per each hour compared to it's counterpart AGM. However, once again, it all comes down the capacity of the 240 Volt battery charger when calculating how long it will take to charge a Lithium battery set up.
Most Lithium batteries have the capability of accepting anywhere between 50-100% of it's capacity when charging per each hour. For example: A 100 AH Lithium LiFePO4 battery with a 80Amp recommended charge rate, can charge from a battery charger (80 Amps in capacity) in a little under 1.3 hours. That's an extremely fast charge rate! However, you would require an 80 Amp battery charger to be able to achieve these charge times and this can be costly.
Overall, yes, your Lithium battery can accept a higher rate of input charge, however, it is still common for the average user to stay between the 10% - 30% rule when adding a battery charger to their system.
Note when using a 240 Volt battery charger on a generator:
Generators are not 100% regulated all of the time in their power output, it is always recommended to use a 240 Volt battery in line between the battery and the generator. By doing this, you will ensure that any fluctuations omitted from the generator are absorbed through to battery charger and are not transferred direct to the battery charger. This ensures a fully regulated battery charge.
When calculating approximately what size battery charger you can successfully run from a generator, use the following guide:
For every 1 Amp of battery charger = 18 watts of power used from the generator
Example: 30 Amp battery charger = 540 watts used from the generator
Home of 12 Volt recommendations:
Home of 12 Volt largely recommends the use of Victron battery chargers. The range of Victron battery chargers is extensive in size to cater for every individual use. These chargers are also designed for multiple chemistries of batteries, such as AGM, GEL, Wetcell and even Lithium LiFePO4.
Backed with a 5 year manufacturer warranty and offering both Bluetooth capability and a waterproof design, these truly are the pick of the bunch when comparing with other brands on the market!