Extra battery for accessories

Extra battery for accessories

It starts with purchasing a VW Caddy, then you find out what it can do and what is available for it. Whatever style you choose, things often get out of hand.

It starts with a rear spoiler, different rims, lowering and then the caddy virus starts. Other radio, amplifier, other speakers, subwoofer, air ride, LED lighting, starry sky, the list goes on. But then after a while you want to start your car… battery too weak or even empty and you must prevent the latter in order not to destroy the battery.

Extra battery for accessories

A must, first of all you relieve the burden on VW’s Canbus system itself and the battery is only used for what it is intended for. Everything you build extra in, on, on, under or behind the caddy that can consume power… connect it to an extra battery and ensure that protection is built in to prevent the car’s main battery from being drained. . This prevents you from ending up with an empty battery in the car itself and also prevents malfunctions in the Canbus system. With an extra battery or more if necessary, you can play with all the extras and enjoy them while you are sure that your car will start later.


How does the accessory battery differ from a starter battery?

An accessory battery is a different type of battery than the starter battery. The latter is, logically, for starting the engine and therefore supplies a high starting current. Where a starter battery can only discharge to approximately 20%, a second battery can discharge up to 80%; although (predominantly) discharging up to 50% is the maximum with a view to a longer lifespan.

As mentioned, a starter battery is designed to supply a lot of current for a short period of time. However, an accessory battery is designed to provide lower and higher currents for a longer period of time, but not the enormous peak currents like a starter battery does.

Why is a second battery needed?

The first reason why you want to buy a second battery for the accessories of your camper, boat or other vehicle is the aforementioned difference with the starter battery. After all, the latter cannot discharge as far as a traction or semi-traction battery can. In other words, the capacity of a starter battery is much lower than that of a typical accessory battery.

Always sufficient starting capacity
The second reason to purchase a separate, dedicated accessory battery is because it is advisable and logical to separate accessory charging from the vehicle’s starting capacity. A starter battery must always be able to provide immediate and full service, meaning there must be sufficient peak current available. This prevents you from being left standing still with an insufficiently charged starter battery at the time of departure due to the use and charging of one or more accessories.

Second battery: semi-traction
In short, a second battery is required to supply energy for the additional vehicle facilities mentioned earlier. The accessory battery is a semi-traction battery, called a deep cycle battery in English. If you hear the term ‘light battery’, there is a good chance that it is the same type of battery. This second battery for a camper, boat, caravan or, for example, a van for passenger transport, is especially suitable for regular discharge.

Which type of accessory battery: AGM, Gel or lithium?

The accessory battery can be an AGM battery, a Gel battery or a lithium (LiFePO4) battery. Depending on the most common applications for which you want to use this second battery, each type offers specific advantages. What are the main differences between these semi-traction batteries? In brief:

An AGM accessory battery is very suitable for systems that require long-term low power consumption, but sometimes also high peaks, such as when making coffee.

A Gel accessory battery is mainly suitable for long-term lower power consumption. This includes supplying energy for lighting or charging electronics such as a laptop or smartphone.

A lithium accessory battery combines both. The lithium semi-traction battery can both charge and discharge quickly.

This type of battery is therefore somewhat more expensive. Do you prefer lithium? We would also like to draw your attention to the following points of interest. Always connect the lithium battery to a BMS (Battery Management System). Additional protection relays are often also required.