Or how to use LEDs to save your battery
Just after I bought the boat I realised that the main cabin lights were making a big dent in the domestic batteries overnight.
The simple answer is to replace them with LEDs. These are brighter and use considerably less energy than standard filament bulbs.
However, I have a BSc in Electronics, so I knew the 12volt supply on a narrowboat varies from 10 volts up to 15 volts and is very electrically noisy. Electrical “noise” is caused by all the electric motors starting and stopping, like water pumps, fridges, bilge pumps, pumps and fans in Webasto heaters. etc, etc. These cause “spikes” on the electrical system of 50 – 100 volts in both positive and negative directions.
At the time, back in 2013, most of the LEDs available, mainly from China, were cheap, badly designed, and wouldn’t last 10 minutes on a Narrowboat supply.
To be reliable an LED needs some complex electronics to ensure it works safely. For a start it needs to work over the whole 10-15 voltage range without getting dimmer or brighter, then it needs protection from all the electrical noise that will damage it, and finally it needs a bridge rectifier so that it can ignore the polarity of the boat’s DC supply (otherwise if plugged in the wrong way round it will blow itself to bits)
So I designed a 12 driver circuit and went to the Crick Boat Show looking for LED lamps that I could feed via the new circuit.
It was here I met Bedazzled LED lighting. https://www.bedazzledledlighting.co.uk/
So I picked up one of their G4 replacement lamps to see if it would physically fit in the housing of the main cabin lights along with my driver circuit. And then I turned it over!
To my great surprise, on the back of the lamp was all the correction and protection components from my design – including a rectifier – already done! So I could actually replace them one-for-one with the existing incandescent lamps. Saving me hours of work.
I had a long discussion with the guys on the stand and ended up replacing every lamp on the boat. 12 years later, as I write this, they are all still working with NO failures – that’s a good design.
I cannot recommend Bedazzled highly enough.
Subsequently, I wanted to light the inside of the lockers where there generally isn’t room for a lamp fitting. I did this with some sticky-back LED strip that Bedazzled supply, see Locker Lights