Selecting the Appropriate Battery Charger Size

Determine the size of your charger by taking into account the following factors:

1. Type of Battery

A charger with an Amp output of 20% of the battery bank is ideal for lead acid deep cycle batteries (AGM or Gel). Therefore, you would purchase a 20Amp charger for a 100Ah battery.

Charging needs vary depending on the type of battery. This is because charging causes a distinct reaction in the battery's chemistry.

For optimal performance and longevity, the charger to battery ratio for lithium and lead crystal batteries is 30%. Therefore, a 30Amp charger is needed for a 100Ah.

2. Profile of Charge

The Maximum Charge Voltage and Maximum Charge Current are included in this.

The maximum voltage at which the battery may be charged is known as the Maximum Charge Voltage.

The maximum charge current that the battery can get during charging is this one.

The maximum charge voltage and charge current must be adhered to when charging the battery. If not, you risk significantly lowering the battery's lifespan and condition.

3. Several Sources of Charging

If you can use more than one charging source simultaneously (as in a boat or motorhome), these shouldn't be more than:

35% of the total battery capacity for AGM and lead acid
Lead Crystal at 30%
Lithium at 60%

The good news is that many chargers can be adjusted to reduce their current output. This makes it possible to install a larger charger initially, which is perfect if you anticipate expanding your battery capacity or number of cell banks in the future. There's no need to waste money on another charger later on. The maximum charging voltage and current for a 200Ah lithium battery are 15.5V and 150A, respectively. These requirements must be met by the charge profile.

Additionally, you should make sure that the battery charger's power drain does not exceed the generator's capacity when using it to power your device.

4. Voltage in the System

The output of your charger must match the voltage of your system.

Select a 12V battery charger if your system is 12V.

A 24V battery charger is required for a 24V system.

Various Battery Charger Types:

AC to DC chargers are made to use mains electricity or a generator to charge your battery.  Therefore, use a regulated charger and connect it to the generator's AC source instead of its 12V supply. This will speed up charging and reduce fuel waste.  If you're in a distant area, hours away from the closest gas station, that's a huge advantage.

For your 12V system, a DC to DC battery charger functions similarly to a smart charger.  A DC to DC charger's ability to increase battery charge while you're driving is its best feature.  Additionally, it serves as an isolator, preventing your starter battery from dying when you stop for a time.