Here is the info on my hombrew battery charger which has been a long running project.
It a 240v-24v charger utilising rewound microwave
transformers, mounted in a steel enclosure force cooled with two microwave fans.
I cut off the high voltage winding of each transformer and rewound with 33 turns of 18g (1.02mm) wire, (two windings at the moment but will be three on completion) no load volts 31.2AC.
At battery volts of 25 the transformers each put out around 25A dropping to 10A at 26.5v. One wire from each secondary passes through a current transformer(CT) for metering. It should be noted that these wires must be in phase(for the CT) or they will cancel each other.
Each transformer is rectified by a 35A bridge mounted a a large heatsink which is cooled by the exiting forced cooling air.
The primary of each transforme is protected by a 16A mcb with a 32A mcb on each secondary.
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Heatsink
Inside overview
fan and transformers
Mcb's with CT below
fan cover
