THE EDGE

Does anyone have any information on what type of battery backup system is ideal for this size of airplane? I was planning on using nimh for my Edge, but not quite sure of the best route for "playing it safe". I see there is alot of systems out there, but not sure what is overkill.

The setup I plan to use is...
4 futaba digitals s9451
2 standard servos (for throttle and choke)
1 s9153 digital for rudder
and a 1100mah for ignition
and a 1650mah for servos and RX


thanks for all your suggestions
CK

papadale

My Feedback: (6)

The best way to fail safe your battery system is to use two switches and two batteries with the extra switch plugged into an extra port on the receiver. This way if one switch or battery dies you will still run off the other. Using this system however usually requires that you disconnect the batterys to charge them because the switches have a common ground. Another option would be to run the switch leads to a y cable and then to the receiver.






Good Luck!
Dale

rctom

I set my planes up this way, 2 batteries, 2 switches, one receiver, extra switch plugged into an unused port. I'm not sure what effect sharing a common ground might have but I've been doing it this way succesfully for about 5 years. I plug my charger into the charge jack on the MPI switch and have never had a problem.

If you use voltage regulators (like with Lithiums) be sure the regulator is on the receiver side of the switch, not on the battery side.


Tom Fawcett
Wild Hare R/C

THE EDGE

Okay, but you do switch both on and the reciever will only draw from the one hooked up to the battery slot(vs the empty channel) in the reciever until that battery shorts or fails, correct?

Also I plan on using my Accucyle to charge these nimh batteries. Will I have to change or watch them more closely or just do as if they were nicd?


Thanks


CK

ezflyr

My Feedback: (32)

During normal operation, both switches will be ON, and both batteries will be supplying power to your receiver. Inside the receiver, all of the "+" and "-" connections are bussed together, so your batteries will be in parallel no matter what you do. There is really nothing unique about the battery port except that it's not also a channel port!

When you are preparing to fly, switch one battery ON and perform a load test as you normally would do. Once complete, switch that battery OFF, and repeat with the second battery. If both checkout fine, switch BOTH batteries ON and go fly!

You may or may not be able to charge/discharge your batteries simultaneously when they are hooked up in this arrangement. It will depend on the switches and/or the charger you are using. Most switches DO NOT switch the ground connection, and this has been shown to be a problem for some chargers/cyclers. If you have this problem, you can change your switch harnesses to units that switch both the positive and ground connections (I think JR switches do this). Again, this only applies if you are charging/discharging both batteries simultaneously. If you are doing them singly, it doesn't really matter. Just be sure to completely charge both batteries prior to flight!

John

flier

My Feedback: (7)

[quote]ORIGINAL: dalees

The best way to fail safe your battery system is to use two switches and two batteries with the extra switch plugged into an extra port on the receiver. This way if one switch or battery dies you will still run off the other. Using this system however usually requires that you disconnect the batterys to charge them because the switches have a common ground. Another option would be to run the switch leads to a y cable and then to the receiver.


I will agree with Dale.
I've got my setup using the spare channel connection.
I also charge the batteries using a charger for each one, each has it's own charge connector.
The switches are HD units (20Ga. wire) with charge jacks.
Two 6V 1650 mAh for Rx.
Using a fast field charger made for NiMH batteries.
Hope this helps

Geistware

My Feedback: (16)

I would use 2-6 volt packs, 2 switches and one receiver.

rctom

Here is a loosely related comment on batteries.

I've always used Nimhs or Nicads and kept everything simple.

I decided to see what the hubbub was all about on Lipo's. I bought two 1700 mah packs and two regulators from Batteries America, cost was about $100. I charge them with my Hobbico Quick Field Charger, $50.

I have not flown the plane yet, but in testing and setting up the radio servo operation is very crisp and consistent. I can actually observe better performance on the bench.

I'll let you know how they work in the air.

Tom Fawcett
Wild Hare R/C

flier

My Feedback: (7)

Thanks Tom,
waiting to hear how they work.
What size regulators did you order?

P.S. web site that Tom is talking about
http://www.batteriesamerica.com/

rctom

I just used the 6v regulators that Batteries America sells for $20 each. Specs are unknown which makes me a little nervous.

TF

montanacharlie

My Feedback: (1)

Hey Tom
I'm really interested to see how they work out also. Are the charges on Lipo batterys suppose to last longer than say a nimh of the same size? I can see the weight benefit, definitely. If a guy does have Lipo's what side of the regulator gets load tested to see the capacity of the battery before a flight. Was thinking of running one of I4C's voltage displays. Should that be hooked up before or after the regulator. Guess these questions aren't just for Tom but maybe for anyone that has had some experience with them. Want to keep my WH extra as light as possible and Lipo's seem to be worth the few extra dollars in weight savings. Thanks.


Charlie

THE EDGE

Thanks for all the info everyone. I just have one last question, is it a good idea to run a 6 volt regulator for each battery or not? The reason I ask is because I have seen that when you turn on a freshly charged 6 volt battery the voltage is above 6 volts and make the servos jitter and chatter for a few seconds until the voltage drops below 6 volts. I just wonder how much strain this would cause on the servo motors not to mention what is going on inside the reciever.



Thank you again

CK

rctom

Yes, it's a good idea to have 2 regulators for several reasons. With only a single regulator you have a single point of failure, if it goes out you're coming down.

Also regulators have current limits, with 2 of them you have double the current capacity.

BTW I discovered something interesting in my Hobbico Quick Field Charger dealing with the Lithiums. It won't do 2 lithiums at one time. When I try to start the second lithium charging the charger thiks for a few seconds and then starts beeping at me. I can do a lithium and one of another type, not no 2 Lipo's.

I have plenty of power into the charger.


TF

Buzykid

My Feedback: (2)

I use two battery system as well with one receiver. But don't just plug it into an open slot use the battery slot and a Y on the channel at the oppisite end of the receiver. that way your power is spread evenly over all the servos, not loading up on the one's right next to it.