Redundant battery
 

Any problem running a 6v regulated 2800 lithium ion in conjunction with a regulated 6v 700 nicad pack as a redundant battery setup?

RE: Redundant battery
 

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RE: Redundant battery
 

If you run two packs with regulators in parallel into the receiver, you will find they work just fine. However, one of your packs may not deliver any current until the other pack is dead. I tried this with two Li-ion packs and discovered that the regulators were mismatched by 0.01 volts. The current flow was only from the regulator with the higher voltage output. My fix was to jumper the two packs together before the two switches and two regulators.

RE: Redundant battery
 

Your setup will not be a problem.
Why do you need two regulators?

RE: Redundant battery
 

will it work with the nicad pack unregulated?

RE: Redundant battery
 

Yes. It will work with 2 nicads (or nickel metal hydride) un regualted. Both packs must be the same cell count but may differ in output (one 800 and another 1200) will work fine together. I however run both at the same output as a personal preference.
EXCAP232

RE: Redundant battery
 

If I were going to do what you describe, I think I would regulate the nicad pack to a lower voltage, so it will be a backup in case the lithium battery goes south.

The nicad would need to be able to supply enough power for a whole flight, and you would need to check the batteries independently (separate switches) before and after each flight.

JMHO.

RE: Redundant battery
 

Can I get away with an unregulate 5 cell 700mh on my DA 50 ignition.

RE: Redundant battery
 

You can get away with the uregulated 5 cell pack for the ign. but i would use 1200 ma min. You do like to fly all day ?

As far as putting two packs in parrallel before the switch thats not a good idea. Anythig happens to either pak and one backfeads into the other . The better solution are the two regulated paks BAT-swtch-Reg-Rec or isolator. I perfer the i4c isolator to seperate the rec. power from the servo power. When using regulators in parrallel be sure to let your supplier know so they can give you a matched set.
My personal favorite are the fromeco adjustable regulators be sure to have a good meter to set them up with. In my 40 % i run the i4c setup with one receiver and fromec regs and bats and it works flawlessly. I have in the past run parallel batery paks and it cost me a plane. I also have had a servo pull down the power bus and put my rec. in bat fail safe,another lost plane. Don't get to cheap it might just end up costing you big.



Tony Fandino
Merry christmas

RE: Redundant battery
 

Say Tony:
Can you explain the failure mode? Are you saying you had one battery pack take a crap while flying and the other pack couldn't supply enough voltage/current to finish the flight?

RE: Redundant battery
 

I had two battery packs in parrallel, into the rec. One pak fails (shorted cell) . There is nothing there to prevent one pak from draining into the other. Voltage droped below 3v and wamo. Regulators act like check valves keeping one pak from draining into the other.


Tony Fandino

RE: Redundant battery
 

I woudl NOT recommend a 5 cell pack unregulated on a DA ignition. More than 6V at any time on that module WILL reduce its lifespan.
Use a 4 cell pack or regulation. The DA ignitions like 4.8 volts.. they run hotter with 6V.

DP

RE: Redundant battery
 

There is a good article on this in RC Report this month.
I would inquire to him about mixing Lithium and Nicad or Nimh. as everybody knows Lithium has a different cutoff voltage than the others therefore you need to protect them differently. Mike

RE: Redundant battery
 

What do you guys think about 2 1200 5cell nimh packs like the ones for mini t's. I can get 2 new ones cheap, would these be ok in a 50cc Imac bird VS 2 2400 Lithy's on regs? They would be lighter.