GarySS

My Feedback: (13)

Just A quick question
Is it correct to believe that LiFe Rx batteries do not require to be disconnected from the switch harness and receiver like LiPo’s do? LiPo’s drain themselves if left connected, but not LiFe’s???
This is in a non electic airplane so there is no ESC involved. Thanks!!

delateurj

It depends on the wiring. If the connector from your battery that you are plugging into your switch has just two wires, then there is not a need to unplug. If it has three wires as some do, then the signal wire (the one other than the red and black, often yellow or white) is actually being used as a center tap. This allows one to balance charge through that plug using something like CellPro 4 with the right adapter. In this case, if you do nothing, when you turn off the switch one of the cells will still be trying to power the receiver and will slowly drain and die because the switch just breaks the connection for one of the wires. One way to deal with this is to make sure the wire from the switch to the receiver is only two wires (red and black). Then again, you don't need to unplug. If you google NoBS batteries and go to their site, there is an explanation and some pictures that explain it probably better than I did.

- Joe.

john4648

My Feedback: (24)

Actually if there is any device drawing current then no battery should be left connected for a long period of time. LiFe's are can be ruined by discharge to zero, especially if held at zero for a period of time. Example - some of the newer Rx switches are fail-safe which actually draw current when in the off position. This is a very small amount of current but a drain none the less. LiFe batteries such as the A123 for instance have been ruined by folks that have left their batteries plugged in during the off season without use or cycling while installed in these fail on systems.

Best of luck
John

johnfly

In any case ...... you HAVE to remove the "white" or "red" wire from the plug that goes to the reciever !!!!!! or the reciever will recieve 3.4 "or so" volts to the signal lead and become non functional. That aside.... it is fine to leave the battery pluged into the switch as long as the switch is turned off when not in use.

Mikecam

If your using the balance connector on the battery to charge it and not thru the switch then no you don't. If your charging thru the switch/chargejack using a 3 wire switch then you should disconnect the signal wire from the switch going into the RX. White for Futaba and orange for Spek/JR. No need to remove the red wire, it will not pass current with the switch in the off position.

What your getting at I think is some regulators draw power but with life packs not needing a reg. your good to go.

BarracudaHockey

My Feedback: (11)

Regulators, power safe recievers and switches, and optical kills will all draw power and you should disconnect.

As someone said though, no reason for regulators with A123's

GarySS

My Feedback: (13)

Seems like there is more complexity than I thought. I am running Futaba equipment with Hobbico heavy duty switch harnesses. No regulator. Digital servos. 72 band. Maybe I will have to closely monitor the battery for a while after flying to see how it acts. THanks.........

pilotpete2

Gary,
The simple answer. If you use a standard mechanical on/off switch and have it setup with the battery connected to the switch harness input and before any of your electronics, then you won't have to unplug the battery, as there will be absolutely no drain on the battery
Pete

delateurj

What PiloPete2 said is the simplest way to look at it. I would just add...."as long as at least one of the following is true: Only two wires going into switch or two wires coming out of switch".

dant-RCU

My Feedback: (3)

I have been flying for two years running dual A123 packs for my receiver. I use 3 wire HD switches. Since I charge both packs with a balance
charger thru the switch ports AND the balance charger uses 3 wires it is imperative that I clip the white/orange (signal) wire that goes to the Rx
only. If you are only charging with a 2 wire charger thru the switchport then you do not have to clip the white/orange (signal) wire to the Rx or
the Rx battery(s).

Thr third (white/orange) signal wire was used to allow hookup of the Tx to the Rx without transmitting on a frequency when setting up servos
and linkages. It is known as Direct Servo Control. Some of the newer radios can perform this function without hooking a DSC cable to the
Rx.

I wired my own packs using a JR/Futaba 3 wire servo lead for the "power leads" which allows me to charge that way.

I have never had any problem or issue with my A123 packs, the wiring or charging via the switchport.

If you connected your battery direct to the power switch I can see no reason to disconnect anything. Just remember to turn off the switch!!

Dan

GarySS

My Feedback: (13)

Thanks to all!!!! On two of my Rx's the switch harness is the two wire variety. My LiFe's were 6.42V when installed a couple of hours ago and I will check them again before hitting the hay tonight.
I'm installing the other two batteries tomorrow in other planes.

GarySS

My Feedback: (13)

Full disclosure: I once fried a $80 receiver by plugging it into a battery lead with a reversed polarity so I’m hyper cautious here……. (OK,dumb to some).
I checked my two installed LiFeSource batteries after the weekend and there has been no voltage decline. But, they were in just two wire switch harnesses (non-heavy duty) so the white wire issue is not present.

I will be using my LiFe charger Tenergy TB6 B, to both balance charge and straight charge by directly connecting it to the battery balance and “Deans” leads and not through the switch harness. So, I don’t think I need to fight the white wire issue that way.

Now in my planes with heavy duty switches:
My Hobbico heavy duty switch harnesses have a connector lead to the battery with only two wires (red/black). But the charger connector lead coming out of the switch is three-wire as well as the connection to the RX being also three-wire (WHITE).

So Joe DeLateur my battery has only a two-strand black/red lead so I should be OK to leave it connected even though the switch has three-strands to the RX.

John4648 I don’t have any regulator or other electronics, just a HD switch so I should be OK leaving the batt connected.

Johnfly, I am uncertain about what you mean….will the battery become nonfunctional (due to being drained) or the receiver become nonfunctional (fried)? Do you still state your warning now that I have clarified my switch harness construction (two-wire strand to the battery)? ??

Thanks for all of your patience! This info might help some others set up their systems.

dant-RCU

My Feedback: (3)

http://www.hangtimes.com/nobsbatteries.html

Check the A123 FAQ and the A123 setup guide (bottom of page).

Dan