Tim Samaras
Guest
- Joined
- Dec 16, 2003
- Messages
- 173
Jason:
If you run enough 'goodies', I certainly do recommend a second battery.
I'm not a huge fan of these diode isolators, so I designed/built my own system.
As Gene suggests, I run a deep cycle battery through a heavy continuous duty relay that 'slams' both batteries in parallel--but only when the vehicle is running. I built a voltage detection circuit that measures the battery voltage..and snaps the relay on only when the vehicle voltage goes beyond 13 volts. When the battery voltage is at 13 volts, that means the alternator is working--thus the engine is running. System keeps the second battery from the vehicle starting current...which sometimes drops the voltage below the threshold of most DC-AC inverters..and would kill the load..which means whatever auxillary equipment you have plugged in...just shut off.
Yuck.
System is completely autonomous..and I don't worry about it.
I do have an over-ride switch that I use which can slam the relay on...which means I can actually 'jump myself'...just in case (for whatever reason) my main battery is dead..and I have a 'core' bearing down on me. This is assuming that one uses heavy enough cable to the second battery to handle the starting current.
One would argue some equalization issues of slamming batteries together..but I haven't had any problems.....yet.
I've been using this system for 8 years--and works well. I wouldn't be surprised if something similar is now commercially available.
Hope that helps!
Tim
If you run enough 'goodies', I certainly do recommend a second battery.
I'm not a huge fan of these diode isolators, so I designed/built my own system.
As Gene suggests, I run a deep cycle battery through a heavy continuous duty relay that 'slams' both batteries in parallel--but only when the vehicle is running. I built a voltage detection circuit that measures the battery voltage..and snaps the relay on only when the vehicle voltage goes beyond 13 volts. When the battery voltage is at 13 volts, that means the alternator is working--thus the engine is running. System keeps the second battery from the vehicle starting current...which sometimes drops the voltage below the threshold of most DC-AC inverters..and would kill the load..which means whatever auxillary equipment you have plugged in...just shut off.
Yuck.
System is completely autonomous..and I don't worry about it.
I do have an over-ride switch that I use which can slam the relay on...which means I can actually 'jump myself'...just in case (for whatever reason) my main battery is dead..and I have a 'core' bearing down on me. This is assuming that one uses heavy enough cable to the second battery to handle the starting current.
One would argue some equalization issues of slamming batteries together..but I haven't had any problems.....yet.
I've been using this system for 8 years--and works well. I wouldn't be surprised if something similar is now commercially available.
Hope that helps!
Tim
