can anyone recommend a transformer/recifier

[ian_374315499]

hello there my set up is as follows 240v mains into a consumer unit my transformer was fed from this which charged my leisure battery and supplied 2 20A 12volt feeds for my toilet lights etc.

now my transformer has blown (the capacitaor had failed) replaced the cap with similar to repair but still its broken.

can anyone recommend a suitable power unit to charge my battery and supply the 12v feeds as mentioned above.

thanks ian

 

[ProfJohnL]

Hello Ian,

In essence what you describe is a battery charger with a transformer, rectifier, and smoothing capacitor. These relatively simple devices are not entirely up to the job, as they can easily overcharge a battery, which can produce hydrogen gas, and eventually will damage the battery if left on charge for a long time.

Most modern caravans have a system that is a little more sophisticated than the device you describe. Most are fitted with a power supply that will produce a stabilised 13.8V. There are different models with different current capacities. Most of these now use high speed switching modes to produce the current without the weight of a traditional high power transformer.

There has been considerable debate on this forum about the choice of 13.8V output. It seems that this is chosen to allow a battery to be connected almost indefinably without producing excess gas. The down side is that the battery is never fully charged. However the supply can actually run a limited number of 12V devices without a battery being present.

There are now a number multi-stage chargers available now which monitor the state of the battery and will switch between modes to maximise the charge. Assuming that these have sufficient maximum charge current capability of about 7 to 10Amps, then one of these might be a solution for you.