Battery drain?

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
frumpy

frumpy

Well-Known Member
Messages
846
Reaction score
10
Location
Stratford,CT
Any guys here running a hitec 805BB servo or any other servo with over 300 oz/in of torque??If so are you running the ''Y'' harness that plugs the servo directly into the battery??Or is this not needed??:helpsmilie:
Will it damage the Rx without it?
 
i used to run with a "Y" harness cause everyone said it was the way to do it, i checked the voltage off my spectrum rx and theres is NO difference with plugging it directly in the rx. On the other hand, since i use 2 servos for my brakes those are wired with a "Y" harness.
Oh, I do run the 805 also for steering.
 
frumpy said:
So buggzy you run the 805 without the Y harness and plug it directly into the Rx?
Click to expand...
don't hook it direct. it can cause too much current to be pulled though your rx. just use the y. eric get another y your rx can be damaged if the steering servo draws too much current. the rx are made for standard size servos that don't draw the current like the 1/4 do.
 
Last edited:
cyclops1970 said:
Well spectrum Rx's , whatever goes in goes out so theres no need for a y harness .. but regular 75mhz rx need the y harness because you don't get the full 6 volts without it ..
Click to expand...

So what ur saying is the "Y" harness is definitely needed to run the 805 correctly? Ive been running it for 1 1/2 yrs and never had any problems.No unusual batt drain, glitching, nothing nada ! FG MT with "1" 805 for the steering and it turns the front wheels absolutely fine. Now im reading this posting and im wondering alittle here(lol).
 
2pock said:
So what ur saying is the "Y" harness is definitely needed to run the 805 correctly? Ive been running it for 1 1/2 yrs and never had any problems.No unusual batt drain, glitching, nothing nada ! FG MT with "1" 805 for the steering and it turns the front wheels absolutely fine. Now im reading this posting and im wondering alittle here(lol).
Click to expand...

no either way will be fine .. just when you run a y harness you get 6 volts from your battery and with out you only get 4.8 volts and with the voltage change it also changes your torque rating on your servo ..
but with spectrum RX's you don't need the y harness .. because if you run a 6 volt battery pack you get a true 6 volts .. what ever the pack is it will handle it up too 7.2 volts ..
so if its NOT a spekrum TX &RX then you "SHOULD" run the y harness ..
 
I've never understood how you use the Y harness.
People say they have their steering servo plugged directly into the battery
how does it know when to steer if not plugged into the rx? seems like they are saying the Y splits the battery and goes to the rx and the servo. how does it back feed to the steering servo. forgive my ignorance, but I'm not seeing the whole picture.
 
it goes from the battery to the servo too the RX and back to the servo with the signal i guess in plain terms .
im no expert by any means but thats a basic discription of it anyways ..
 
what ever the pack is it will handle it up too 7.2 volts ..
Click to expand...

Its actually crazier then that!:)
With the Spektrum the receiver can handle up to 9.6 volts. The real limitations are the servos. Some servos are capable of operating at higher voltages while others are not. Check with the servo manufacturer that you're using for specific details.
 
Bigger the Better said:
Its actually crazier then that!:)
With the Spektrum the receiver can handle up to 9.6 volts. The real limitations are the servos. Some servos are capable of operating at higher voltages while others are not. Check with the servo manufacturer that you're using for specific details.
Click to expand...

true good point !!
i should keep my mouth shut i always forget things or cant explain them correctly ..
 
Hmm, I was under the impression that if you supply the radio with six volts, you get six volts from the receiver.

I understand it drops to 4.8 if you use an ESC on an electric car, but why would they sell 6 volt packs for smaller 1/10th scale nitro cars if you only get 4.8 volts? Not even the pro racers use Y harnesses on their 1/10th or 1/8th nitro cars and they all run 6V packs.

AND I just did an experiment. If you hook up a servo through the receiver with a 4.8V pack you get a slower speed then when I plugged in the 6V pack.

I've been using the 6V packs with my large scale servos and hooking them directly to the receiver for about 10 years now. NEVER had an issue.

Not sure if all receivers work like this BUT if you have a Futaba receiver with BEC (they all have it now) and you plug in a battery pack directly into the receiver, the BEC shuts off and delivers a full 6 volts. Technically it bypasses it.

If you install an ESC for an electric car and the receiver is powered through a "channel" port the BEC is activated.

It doesn't HURT to use the Y harness but for me personally it has not been necessary.
 
Last edited:
6 Volts in 6 Volts Out

Take a volt meter & check it! 6 in & 6 out.
hpiguy said:
Hmm, I was under the impression that if you supply the radio with six volts, you get six volts from the receiver.

I understand it drops to 4.8 if you use an ESC on an electric car, but why would they sell 6 volt packs for smaller 1/10th scale nitro cars if you only get 4.8 volts? Not even the pro racers use Y harnesses on their 1/10th or 1/8th nitro cars and they all run 6V packs.

AND I just did an experiment. If you hook up a servo through the receiver with a 4.8V pack you get a slower speed then when I plugged in the 6V pack.

I've been using the 6V packs with my large scale servos and hooking them directly to the receiver for about 10 years now. NEVER had an issue.

Not sure if all receivers work like this BUT if you have a Futaba receiver with BEC (they all have it now) and you plug in a battery pack directly into the receiver, the BEC shuts off and delivers a full 6 volts. Technically it bypasses it.

If you install an ESC for an electric car and the receiver is powered through a "channel" port the BEC is activated.

It doesn't HURT to use the Y harness but for me personally it has not been necessary.
Click to expand...
 
well i learned the hard way,i used a 7.2 battery on my truck and fried a 5745
went a bought a 805 and a voltage regulator now all is fine....not using the Y connector
 
Back
Top