Sentry Converter

[Leigh]

My 1985 B28 has an original equipment Sentry Converter/Charger which works fine to charge the original 2 battery DC system. I don't have a manual for it. I plan on adding a third "house" battery to power a converter, the DC fridge, a backup fwd bilge pump and maybe some other stuff. The Sentry shows two(2) "+" terminals for output. Does anyone know if it can be used for a third battery? I plan on using an isolator for the port alternator which will charge the house battery and port starting battery. Can I do the same thing with the charger? I would like to keep it as long as it works. Thanks, Leigh

[Bruce]

One way to do it would be to open the charger and add another diode to the current two.

Depending on the year, there would most likley be an aluminum plate(heat sink) with the anode end of the diode pressed into the plate with the cathode going to a fuse or dc breaker for over load protection and then to battery plus.

Old style silicon diodes were pretty crappy.

Other wise buy an isolator rated for your charger output, 1 alt/two batteries.
Connect the charger to the alt terminal then the others to the batteries.

If you don't and tie the batteries together on the same charger out put
terminal, your connecting the two batteries directly together.

The nice thing about modern chargers is that the banks are monitored and charged seperatly from each other.

The old ones didn't they would monitor only one battery.

The non monitored battery would charge when ever the monitored battery did.

You might be able to upgrade the old sentry style board to the new depending on the exact model.

[Leigh]

Thanks Bruce!