Kate TaylorSee other accessory reviews written by Kate Taylor
Digital Content Manager
Read our expert's review of the CTEK MXS 7.0 – the best battery charger for caravan leisure batteries in Practical Caravan's test of eight chargers
There are numerous ways to replenish a leisure battery — one is via a smart charger. We explain how they differ from regular examples, and test eight units.
Over the past couple of decades, 12V-battery technology has come on in leaps and bounds. Both leisure and starting batteries require less maintenance than ever before, despite packing increasingly more power and electrical capacity into smaller units.
At the same time, though, the latest battery technologies are much less tolerant of abuse than earlier versions. Leaving one in a very low state of charge for long periods is an easy way of damaging them – often irreversibly.
Unfortunately, alarm systems and countless other electronic devices steadily drain batteries of their power. As a result, the cells in caravans that are left in storage for long periods quickly reach that dangerous state of prolonged low charge.
This is precisely why so many battery chargers are now geared towards preventative care, with gentle conditioning modes that keep a battery topped up at all times. Of course, this means the unit has to be powered and left attached to your vehicle or van, which poses practical problems. If you're enjoying caravan holidays in sunny France or Spain you might be interested in a solar powered battery maintainer, but for most of us the British weather provides too little solar for most of the year. Smart modern battery chargers and conditioners are the answer – but there are lots of them on the market, so what features should you look for?
It’s certainly a benefit if a charger is fully sealed against the elements. They cannot be used in the open, but they can be left safely in sheltered conditions, such as the battery box – even if it’s slightly damp.
Powering the charger can be more of an issue, especially if your caravan is in a storage facility with no mains supply handy. In this situation, frequent recharges are the only option, and another common feature of modern smart chargers becomes invaluable: a reconditioning/desulphation mode.
If you know that your battery’s charge has been allowed to drop to a very low level for a long period, a timely charge – with the unit set to reconditioning mode – will often be enough to dissolve damaging sulphation from the battery’s plates before the deposits have a chance to become permanent and reduce the battery’s effectiveness.
As with conventional chargers, we prefer modern chargers that have decent lead lengths – for easier positioning – plus an informative display, so we can see at a glance whether the battery is empty, partly charged, full or in a maintenance conditioning cycle.
Output is another consideration, but it’s not as important as is often thought. While it’s true that a meaty 150Ah leisure battery will take forever to charge from flat with a low-output charger, it’s often overlooked that a battery will only draw in what it needs. For instance, connecting an average-sized, partially charged leisure battery to a charger will often result in initial current draws of 10-15A (if the charger can supply them).
However, after a couple of minutes, current draw normally drops significantly – often to 6A or less. The old practice of dividing a battery’s Ah rating by 10 to derive the optimum charging current is only partially true. A charger with a maximum output of 10-12A won’t significantly outperform one with 6-7A – not, at least, with most battery sizes commonly found in caravan battery boxes.
Arrayed on the Practical Caravan test bench we had eight battery chargers to test that all looked pretty similar at first glance. We set to work, testing the £47 Clarke CC120, £60 CTEK MXS 5.0, £65 Ring SmartCharge+ 12, rather pricey £190 Ring SmartChargePro 25, £37 Sealey Autocharge 10D, £60 Draper 11953, the £133 Draper 07265 – and this one, the £100 CTEK MXS 7.0 battery charger.
As a result of our Practical Caravan test of these eight rival leisure battery chargers and conditioners, we have found a clear winner. The CTEK MXS 7.0, at £100, impressed our tester above all the rest – here's why.
Brimming with the latest technology, CTEK’s MXS 7.0 is equally effective as a 12V power supply (up to 7A output), a fast charger, and also a long-term battery conditioner.
While the maximum charge current is a relatively modest 7A, that’s still adequate for the rapid charging of most batteries.
The charging speed is aided by modes for specific battery technologies, plus a clever pulse at the start of charging that cleans the cell’s plates and maximises their performance.
As practical as it is clever, the MXS 7.0’s fully sealed construction allows it to be used in relatively sheltered outdoor conditions.
We've awarded the powerful and high-tech CTEK MX 7.0 battery charger five stars and crowned it our mighty test winner.
- You can use it outdoors
- It recharges batteries quickly
- It copes with various battery types
- It only delivers 7A, but this seems to be enough to recharge most batteries