high current regulated charger

Thread Starter


Joined Mar 25, 2008
I need a circuit that can deliver at least 50 to 60 amps at 12vdc from a 24vdc power source, we have a old military truck that has a 24 volt system and we need a 12 volt regulated circuit to charge/maintain a secondary 12 volt system with its own 12 volt battery to run all of our emergency equipment, thanks in advance Dan


Joined Jul 17, 2007
Hi Dan,
Although your situation is vaguely similar to the original poster's problem, it's really a different application (automotive) and has it's own unique problems.

In such cases, you should start your own thread rather than "tacking on" to an existing thread, otherwise it is considered "hijacking" and is bad form.

In your application, I would recommend adding a secondary alternator. The mil-spec alternators that have been supplied on military vehicles for many years are pretty robust, but even your basic truck has it's own power requirements. I'm afraid that attempting to run all of the 12v emergency equipment in addition to the basic 24v requirements may not leave enough reserve power to recharge the main batteries in a reasonable amount of time, leading to early battery failure - and those big 12V batteries are expensive!

I suggest that instead of trying to use a "buck" converter to get your 12v system powered, that you have a 2nd alternator fitted to charge/run your emergency equipment. GM makes a 130 Ampere alternator which is quite popular for use as a retrofit item. Some alternator rebuild shops install even beefier rectifier/regulation circuits in these alternators, which keeps them running cooler and longer. Of course, you will have to have brackets fabricated by a welding and/or machine shop in order to mount it, and you may have to add a V-drive pulley.

What kind of truck do you have?