articles/Copy_of_Copy_of_Copy_of_Copy_of_Copy_of_Copy_of_Copy_of_Cream_Employee_Orientation_Presentation_2.png

Oct 13, 2020

A Guide To Auxiliary Batteries

When setting up your overlanding vehicle, having power off grid is often a necessity. Whether it’s to power lights, a 12v fridge or a whole range of luxuries from home, you’re going to need an auxiliary battery. Using a secondary battery, and in-vehicle battery charger means you’ll never be left with a flat house battery or without power on the road.  

In choosing an auxiliary battery, the simplest answer to the question of ‘what battery should I get?’ is often how much are you willing to spend? We could spin various combinations when it comes to batteries, but budget is usually the tipping point. With that being said, each battery type has its own merits with differences in sizes, weights, and chemistry that can influence which you end up choosing for your next dual battery setup.

 

Standard Lead Acid

 

A standard lead acid battery will be the kindest on your wallet. These batteries are great for all applications, especially for someone setting up their first dual battery system. They are also very flexible in terms of mounting location, as they can be mounted under the hood if there is no canopy or in-vehicle room available.

The major downfall of standard lead acid is the weight with these batteries starting at approximately 60lbs. This adds a significant amount of weight to any touring setup and must be taken into consideration. They also require regular maintenance, needing to be topped up with electrolytes using distilled water.

 

batteries mounted in an engine bay

 

Calcium

 

Coming in at the same price and weight point as standard lead acid, the benefit of calcium batteries over standard lead acid is that they are sealed, meaning they’re maintenance-free. Like a standard lead acid, they can also be mounted under the hood and used as either a house or secondary battery.

The major downfall of standard lead acid is the weight with these batteries starting at approximately 60lbs. This adds a significant amount of weight to any touring setup and must be taken into consideration. They also require regular maintenance, needing to be topped up with electrolytes using distilled water.   

 

Gel/AGM Batteries

 

As we move into Gel/AGM Batteries, we also start to move up in price. Though they aren’t much dearer than standard lead acid or calcium, it does pay to note that they cannot be mounted under the hood as the heat is too much and can be detrimental to battery life. This means that they can, however, handle deeper cycling without dramatically shortening battery life. They’re also a similar weight to both calcium and standard lead acid, starting at about 60lbs for 100 Ah.

Both AGM and Gel batteries have a similar reaction when charging which is why they share a charging profile on our battery chargers. Although, like all batteries - besides lithium - it is not recommended to discharge below 50% to extend battery life. When deciding on a gel or AGM battery, because of the precise charging needed, you will need to purchase a charger with a specific charging profile.

 

charging auxiliary batteries with REDARC

 

Lead Crystal

 

The newest battery to the market, lead crystal batteries are another step up in price from AGM/Gel batteries. Though this increased price is not unwarranted, as lead crystal batteries require 30% of the total Amp Hour rating in charge current to achieve 100% state of charge. They can also recover from deep discharge better than other battery types as they’re able to accept higher charge currents.

Lead crystal batteries are built tough, and because of this tend to be quite heavy, with a 100Ah battery starting at about 70lbs. But this toughness means that they can withstand high heats and be mounted under the hood.

 

charging two batteries in your engine bay

 

Lithium

 

The latest and greatest in secondary batteries, lithium (LiFePO₄) is leading the charge when it comes to innovative battery features. At one third of the weight of other battery types, a 100Ah lithium battery starts at about 25lbs. This makes lithium an easy choice for anyone who’s conscious of their touring vehicle’s weight. Although they are smaller than most battery types, they can maintain a higher output voltage during discharge cycles.

While other battery types are not recommended to discharge more than 50%, lithium batteries can handle up to 80% discharge meaning they have much more usable power than other battery types of the same amp hour rating. In addition to this, lithium batteries can handle a higher charge current, meaning they recharge quicker than other battery types.

The downside of this innovative technology is that it comes with a hefty price tag when compared to other battery types. Another downfall of lithium is that because of their unique chemistry, you will need a charger with a specific lithium charging profile to ensure that they’re being recharged properly without damage. For more information on lithium batteries check out our blog post on the cost of lithium batteries.  

 

choosing the right auxiliary battery for you

 

No matter which battery type you choose for your setup, it’s important to have a charger that will charge effectively without damaging this battery. REDARC’s range of In-Vehicle Battery Chargers are perfect for any setup, providing effective charging for all battery types – including gel/AGM and lithium.

For more information on designing and setting up a 12v system in your rig checkout Shaun Whale’s video on 12v setups.

 

Leave a Comment

Your email address will not be published. Required fields are marked*

-->