Advice on charging lithium (LFP) batteries for optimum battery care

July 21, 2020

The long summer days are teasing us to get away, dreaming about blue skies and white sands. With the ever-changing travelling advice and hassle, holidaying on home soil is suddenly becoming quite attractive - it's looking like the year of 'staycation'! With campsites reopening, there’s no better way to get away safely than exploring nature with your own leisure vehicle. If you’re lucky enough to own a motorhome, or even a converted van, you should be familiar with batteries for auxiliary power. So, if you have an Essential battery or any other lithium-ion battery installed, this article will outline the best charging practices for optimum battery care.

We asked our customers what they wanted to know about battery charging. Take a look at our answers to the most frequently asked questions.

How to look after your battery before you travel

Is it better for my batteries' lifespan to keep my battery connected if I’m not using my leisure vehicle for a long time? Would it be better to keep it connected to a charger or just charge once a week?

In general, you should make sure your lithium battery remains 50% charged. If batteries are not in use, they should be shelf-stored in a dry cool environment - typically, the battery compartment within your leisure vehicle is an ideal location to keep your battery. Before you are ready to use the battery, you can use a trickle charger to ensure the battery is 100% charged. A simple 1A trickle charger is sufficient to safely keep an Aceleron Essential battery topped-up when in storage.

Best practices for charging your battery

What charger can I use with my lithium battery? Is there a specific charge capacity?

If you have already invested in equipment but are thinking of making the switch to lithium-ion, you’ll be happy to know, Aceleron’s batteries are compatible with lead-acid chargers. We do recommend that you select a charger designed for the chemistry of your battery, so you can enjoy benefits such as faster charging.

How often should I charge my battery?

How often you charge your lithium-ion battery depends on how it's used. If it is used heavily and fully discharged often, it will need to be recharged often. If it is used sparingly, it can be charged at a similar rate. It’s a bit of a balancing act as typically, batteries should not be left fully discharged or fully charged.

How should I charge my battery to maximise its battery life?

Battery longevity, much like people, is all about moderation; excessive high-power operation (charge or discharge) or frequent exposure to extreme temperatures are key examples of behaviour that will reduce the battery lifespan.

How does a battery charger connect to a battery with no solar panels?

The Essential battery can connect directly to any 12V charger. It is compatible with a lead-acid charger but will charge faster with a recommended lithium charger. Standard alligator clips can be attached across the terminals or M8 lugs can be bolted down on the battery for more permanent configurations. A typical charger connects to the battery via the grid.

I don’t have a charger. Is it advisable to just disconnect my engine and leisure battery when they are not in use?

Lead-acid batteries self-discharge at 4-5% a week when they are disconnected from charging. Lithium-ion leisure batteries discharge around 3-5% per month. If you want to disconnect a lead-acid leisure battery, we recommend getting a small solar car battery charger (5-15 watts), that should trickle-charge it if it’s sunny. If you have a lithium-ion battery, you could leave it disconnected for 3-5 months without any issue.

In short, with a lithium battery you should be able to get away with minimal maintenance charging. See our lithium battery in use in a motorhome.

For those of you who are battery fanatics and want to know the science behind charging your battery, here are some technical details:

For a lithium battery the structure of the positive terminal is variable when it is depleted of electrons for long periods of time, which can lead to permanent capacity loss. However, lithium’s low self-discharge rate means, that it does not need to be stored at 100% state of charge (SoC). In fact, a lithium battery should be stored near 50% state of charge – which equally distributes the electrons on the positive and negative terminals.

Or more simply, lithium battery chemistry is a bit like a hydro dam’s reservoir. In an ideal world, it would be best to keep the reservoir half full. An empty reservoir, and you have no power; but an overfilled dam can cause issues that damage the dam (overflow etc).