FEATURES - Atkinson Electronics

1 trailer battery charging MODULETBCM-40 AATKINSON Electronics , 10/01 Web Site: by:FEATURESvThe TBCM senses the alternator charge voltage,sending charge current to the trailer battery . vDisconnects trailer battery from vehicle s chargewire when not charging , (engine is not running)preventing two dead batteries. vWorks with existing 12V trailer wiring, includingon-board 110V AC chargers. Handles most towingvehicle alternators. vMount the TBCM in the trailer battery box orengine compartment, connect only three wires . vThe TBCM doesn t have a .75V drop to sulfateyour battery like RV type & OPERATIONThe TBCM-40A connects the vehicle s auxiliary batterycharge wire and the trailer battery positive wire togetheronly when the vehicle s engine is running and the alternatoris putting out charge current. When not charging , bothvehicle and trailer batteries remain isolated, preventingboth from discharging when a trailer load is left on.

2 Thisisolation continues even if the ignition switch or lights areleft on. The TBCM-40A relay handles the charging currentsupplied to the trailer battery only. The TBCM-40A is powered by the Red main battery wire,(drawing less than 2 mA continuous current). When thealternator output voltage exceeds volts ( ), theTBCM switches on the relay, lighting a LED, sharing thecharge current between the two batteries. To prevent shortcycling of the relay, the TBCM does not de-energize therelay unless the combined battery voltage drops , (the result of the motor turning off, the starter beingenergized, or the battery voltage settling back to a fullycharged condition). If the main battery is almost fullydischarged, the TBCM waits until the main battery scharging voltage exceeds volts before connecting thesecond battery . The TBCM-40A is thermally protected to disconnect incase of internal arcing or other high temperatureconditions.

3 DO NOT USE on any system other than a 12 VDC. For higher current applications use the INFORMATIONTBCM-40A- trailer battery charging ModuleHandles up to 40 Amp "W x "L x "H WEIGHT:10 ounces W/ 40 Amp. contactorand wiring. ENCLOSURE:Epoxy potted in PVC plastic toweatherproof. MOUNTING:#6 x " screw or double stick tape. POWER:9 to 15 V DC from vehicle s battery CONNECTIONS:R/R 12in. #10 AWG charge wireR/BL 12in. #10 AWG trailer +Bat wireBLK 18in. #16 AWG trailer - Bat wireCURRENTS leep mode [ 2 mA CONSUMPTION:Charge mode [ 120mA THRESHOLD:On @ DC DCOff @ DC DC INDICATION:LED indicates charge mode CAPACITY:Up to 40 relay rated @ 40 :In-operative above 858 CTEMPERATURE:-30 to 758 CINSTALLATION CONFIGURATIONTRAILER battery charging MODULETBCM-40 AATKINSON Electronics , 10/01 Web Site: by:APPLICATION 1 - MOUNTING IN trailer battery BOXThe vehicle battery should be continuously connected to the alternator output.]]

4 The auxiliary or trailer battery and crankbattery are connected thru the TBCM-40A relay to charge the trailer battery only when the alternator is 2 - MOUNTING TBCM-40 IN TOWING VEHICLE ENGINE COMPARTMENTThe TBCM-40A senses when the alternator is charging the vehicle battery and closes its contact, passing the alternatorcharge current to charge the trailer battery . The TBCM-40A isolates the trailer battery from the vehicle battery when the alternator is not INSTRUCTIONSBATTERY BOX trailer your trailer s battery wires to make sure which is the positive and negative battery wires. Use a meter to measure 12V DC for positive and negative terminals if the 12" #10 AWG Red/Blue wire with the ring connector to the trailer battery positive terminal. the 12" #10 AWG Red/Red wire with the barrel connector to the trailer s towing harness battery the 18" #16 AWG Black wire to the trailer battery negative the TBCM module to the inside of battery box with the double stick VEHICLE your vehicle s battery wires to make sure which is the positive and negative battery the fused auxiliary battery wire going to the trailer the 12" #10 AWG Red/Red wire to a fused towing vehicle positive wire or battery fused connector.

5 Replace the barrel connector if the 12" #10 AWG Red/Blue wire to the battery wire going to the trailer the 18" #16 AWG Black wire to the towing vehicle battery negative terminal or the vehicle s frame. the TBCM module by screwing the module to the vehicle firewall or other acceptable location. Your TBCM will now monitor the alternator and switch charge current to the trailer battery whenever the alternator ischarging. It isolates the batteries when the engine is off. If the trailer battery is fully discharged, the TBCM may go thruseveral 5 second cycles until the trailer battery voltage comes up enough to stay constantly on.