Flat Battery – Trickle in some current!

2 min read

I’ve driven the BX and Freelander a total of 5 times in the last two months. Neither is on the freshest battery. I’ve been a little concerned about needing to go somewhere, then finding the battery is flat. But my little CTEK trickle charger has become my go-to solution for positive battery preservation!

CTEK connector on the BX

The standby power consumption of the two cars is quite different. The Freelander is a drive-able computer with many ECUs but a clever system to isolate many of its systems from the battery. The BX only has only two micro-controllers. One for the engine and one for the alarm/immobiliser. However, it is rarely driven far enough to charge an AA battery.

The CTEK XS3.3

I first bought a trickle charger in 2015, a CTEK XS3.3, for the princely sum of £35 on Amazon. At the time, this was cheaper than even the lowest cost Aldi clones. With a modest 3.3A charging capacity, it’s not designed to charge batteries from flat (although given enough time, it will). I bought it with the sole intention of preserving the ageing Bosch battery, which was already ten years old.

The CTEK MXS3.8 with a more advanced trickle charge control

Both cars now have a permanent CTEK connection to the battery, a very convenient addition at about £4 each. The XS3.3 is no longer made. The nearest equivalent is the MXS3.8. This newer model has better conditioning and recovery features and just a little bit more output power.

The XS3.3 weighs little, is very compact and quick to install under the bonnet. I typically run a 230v extension lead up from the floor into the engine bay and plug the CTEK unit into there. Not strictly a dry zone, but the bonnet keeps the rain off when parked. The CTEK itself has a (low) IP rating, so condensation and humidity aren’t a problem.

The initial investment has more than paid for its self. I’m happy I bought it. The BX battery has limped another five years until being swapped out at nearly 15 years old. The CTEK has been used to charge the kids second-hand electric quad bike (2x6v), which came without a charger. It has been used to test small 12v items like motors, bulbs and lights, and now amid Covid19, it is on a rotation with the Freelander. The Landy started the first time yesterday after very little use and a 7-year-old battery. I would strongly recommend the CTEK brand if you’re looking for a trickle charger!


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