Your battery should never go "stone dead" or it will simply be trashed every time. You need to use/install a Low Voltage Disconnect.
Depending on the supply... simple battery charger and backup connections can be done using a high current diode and a proper size resistor. Some supplies need to be modified so the voltage & current don't "back-feed" through the regulator circuit. You could also use a current limited source to ensure the power supply remains within normal limits while the system is under normal full load. ... but the resistor - diode method is simple. Consider a marine/rv 2nd battery isolator if you can't work out the diode - resistor methode. You didn't say what type of batteries you plan to use. Lead Acid batteries will take a lot of abuse. Surplus commercial radio/telco site type chargers are all over ebay. Why not run off batteries and simply recharge the batteries from the standard comm site charger. Otherwise there is always the trusty high current relay method. It's not hard to get creative with something that works well. cheers, skipp > "Lou Aiken" <[EMAIL PROTECTED]> wrote: > I want to use the thing as a battery charger at a repeater site. > > The supply does not appear to have a current limiting circuit to > limit the transformer temperature in cases where the battery can > draw too much current due to a shorted cell or a "stone dead" > situation. I want to provide that feature. > > I also want the output set at a 12V battery float voltage of 13.4 - 13.6 volts, and have the ability to adjust the output up to about 14.7 volts, the so-called absorption charge voltage. > > So tell me how to get a copy of your schematic. > > Anything you can tell me about unreliability would also be welcome, but I suspect the voltage regulator and/or lack of current limiting may be the root cause of the issues you mentioned. > > Lou Aiken <[EMAIL PROTECTED]> > LaMer LLC N4SWR > 27109 Palmetto Drive > Orange Beach, AL > 36561 USA > > Tel ++ 1 251 981 6786 > Fax ++ 1 251 981 3054 > cell ++ 1 251 979 4648 >
