Hi Robert,


I have 2 questions regarding switches.

1. I am planning to run a 2 Li-Po battery system through a Smart Reg and Power Expander for redundancy in my 30% Yak 54 (as in the attachment). Is it in your opinion necessary to run fail-safe switches with a setup like this? It seems to me that even if one of the switches fail, the other battery and switch will run the system and get the plane on the ground. I ask because it sounds like the fail-safe switch expose the batteries to a small load even when the switches are off, making it necessary to disconnect the batteries after every flying day to keep from draining and ruining the batteries.

2. Do I need any other switches other than the two for each battery? (and one for the ignition) i.e. Does the Super Reg or Power Expander need a switch?


Thanks again for a great line of products and for the time to explain their use!



Best Regards,

Dave Killmer

Hi Dave,
Nice diagram, it made things very clear. If you want to use two heavy-duty switches this works just fine and, as you say, if one switch failed the other would continue to work. The only thing I would say here is to watch what you put back into the batteries to make sure both switches are working fine or test each switch with the other off occasionally to make sure you have not had a swith failure. The failsafe switches are just a personal preference for people that like a single switch instead of two and do not mind disconnecting the batteries when the plane is stored for a week or more.
Also, you have all the switches covered.
Please let me know if you have any other questions.

Hi again Robert,

Thanks for the quick reply again. One thing you mentioned; if I decide to go with the failsafe route you said I could get away with one switch for both batteries instead of two? Now I would be interested in that. Would you mind expanding a bit on how to do that?

Also another question comes to mind: Is charging a big deal, or do you just plug in the Li-Po charger into the switch receptacle?

And on a similar note, in order to check voltage levels with a meter, is it just a question of again plugging into the switch to do that?

Thanks!!

Best,

Dave Killmer

Hi Dave,
If you use a failsafe switch with the SuperReg, it is a single switch that turns the regulator on/off. You are right though that it draws a small amount of current, about 10mAH/day, when in the off position. Using the failsafe switch you also need to mount two charge jacks which we provide for charging the two batteries. You can also check each battery through its respective charge jack.
Let me know if you have any other questions.