extra voltage at reciever

[trackmagic27]

heres the deal, i just bought an mx-3 and a trinity 5 cell 7.2 volts but i didnt knew it was 7.2 volts and i thought that it was 6 volts because the lhs told me, so i connected the 7.2 volts pack to the reciever and it was acting very strange, moving faster, it stayed hooked for about 5 mins, so my question is, are the servos and the reciever messed up or are they ok?
and in the meen time while i get the rx pack, can i use alkaline batteries with the mx-3?

 

[Rolex]

You're should be okay with it. It's a good thing you disconnected it, rather than leave it on and keep fiddling with it. These things can take a little more or a little less voltage in either direction without a permanent problem, but don't behave well either way.
Yes, you can use alkaline batts. Most people run alkalines in the radio and rechargables in the car. The radio uses far less power than the servos.

 

[Candyman]

If it's 5-cell it should be 6.0 volts....

 

[Rolex]

Candyman is right. I missed that. Rechargable cells are 1.2 volts each, so a 5 cell pack should be 6 volts. It's what most of us run.
I'm not sure what an MX3 is. Is it nitro or electric? The pack you bought was just for the reciever? Check the label and let us know what the voltage and Milliamps are.

 

[sweetdiesel]

I have a 1400 mah 6 volt hump receiver pack (forgot the brand), and it consistently charges to about 7.4 volts before it peaks. I am using a charger with delta peak protection set at 15 mV. Should I be discharging to 6 volts before I run it? I thought the 6V was the minimum amount that the battery is rated for not the max. So far I haven't been getting any wierd stuff happening.

 

[Wardo]

I have a 1400 mah 6 volt hump receiver pack (forgot the brand), and it consistently charges to about 7.4 volts before it peaks. I am using a charger with delta peak protection set at 15 mV. Should I be discharging to 6 volts before I run it? I thought the 6V was the minimum amount that the battery is rated for not the max. So far I haven't been getting any wierd stuff happening.

First, Rolex. An MX3 is an Airtronics radio.

6 volts, 1.2 per cell is a rating, when under a load with something discharging it, it will read under that number. When being charged it will go over that number.

You'll see the voltage drop when it's disconnected from the charger.

 

[trackmagic27]

re

well, i bought the super brain so i connected to check the rx voltage and read 7.4 volts or something like that. it is a Trinity 1200 MaH and it is a 5 cell hump back.

BTW, the servos were moving a bit faster, i dunno if its because of the new radio, and it was making a weirtd noise.

 

[Wardo]

Was the charger charging the pack or did you use it as a DVM to take the reading?

 

[trackmagic27]

no, the charger was not charging the pack, but i have no clue to what DVM means.
i was using the alligator plugs and the extension of the bat to check the voltage.

BTW, does this new radio make the servos move faster and a better response? and having a new radio and reciever cause a strange noise comming out of the servos?

 

[Plaidfish]

DVM is Digital Voltage Meter...
if you have Digital Servos they will always make a high pitched humming when not PERFECTLY centered...digital is always trying to find perfect center and when it can't they whine.....for a simple explanation that should work.....the voltage is reading higher than 6v because the Batt should be at 6v when there is a load on it, that is if I am understanding Wardo's post....I'm not that savvy w/ chargers and Batts yet but that sounds right....

 

[trackmagic27]

re

so my rx pack is actually 6v?
heres the link to my rx pack
http://www.teamtrinity.com/batts/receiver.asp
its the last one from top to bottom of the list on the right side. (humpback)

btw not to make another thread, when adding diff oil for the first time, when you open it a silverish grease was already inside, should i remove it and clean the diff thorughly or should i just leave it there and add diff oil?

 

[Wardo]

the voltage is reading higher than 6v because the Batt should be at 6v when there is a load on it....

The pack should be around 6 volts when it's sitting without any draw or charge being put into it.

The voltage will read over 6 volts while a charge is being put to it.

The voltage will read under 6 volts while there is a draw on it (it is power something)

 

[trackmagic27]

so the only way to check if iit is the correct voltage is to charge it, then test and see the voltage?

BTW, anybody have an to the diff question?

 

[olds97_lss]

For the diff, clean out the grey crap and fill with new oil.

As for the batt pack, I have the same thing with my receiver packs. I made them out of NiMH 2100Mah AA's. I don't have a peak charger, I just check the temps as it's charging on my cobled up charger that I bought from radio shack. The charger was built to handle 4.8v - 7.2v packs from 1100Mah to 2100Mah. There is a switch to go between NiMH, NiCD and there is a switch to go from normal capacity batts to high capacity batts. There's a little chart on it so I know what it thinks normal and HiCap are.

Anyway, as the packs are charging, the temp rises from sitting temp to about 5 degrees higher or so and I unplug it. When I check the volts with my DVM when it's disconnected from the charger, it reads anywhere from 6.9v-7.2v. If I let the pack sit for an hour or so without using it, it will drop to about 6.7 and stay there or around there for a day or so then start dropping a little every day. Now, instead of checking the temps, I just charge to 7v even and unplug it.

I've been using the same packs for about 2 years. I also use the same cells in my receiver. 1.2v X 8 is 9.6v, but I leave it plugged into the xmitter charger until it hits 11v and after sitting an hour or so, it will drop to about 10.7.

I get many hours of runtime out of the receiver (with 2 high torque non-digital servo's) and many hours out of the xmitter before either get low enough to worry me.

The trucks I use the packs on both are running the airtronics recievers that came with the mx-3 xmitters. But I have one xmitter that I use and I just swap the crystal and model number when I change trucks.

If the volt levels I charge too are bad, I haven't really had any problems with it to know if it is or isn't. Everything works fine all the time, but driving in my area is really glitchy regardless of the radio/receiver/battery pack/truck. I think there's a buttload of interference around here, but it's nothing bad enough to keep me from driving. Just a little twitchy from time to time.

 

[trackmagic27]

so it is safe to say that my reciever pack is in fact 6V but because that it might have comed charged it was 7.4 volts?
BTW, anybody with a Super brain 959, could you explain me how to use it, I've read the instructions but couldnt figure out how to. these is how i think i do it:
first you change the amp rate to .5 AMPS, then you plug it in with your alligator plugs, once done that, you click the start button and it will start charging an automaticly stop when at peak. am i correct? am i missing annithing or do i need to adjust something first? what about the threshold peak, whats that?

 

[sweetdiesel]

is yours the pro model? mines the pro, don't know about the other one.

 

[trackmagic27]

what? the charger? if yes, no, its the normal 959, i believe the one up is the 969 but its about 80 buks.

 

[sweetdiesel]

I have the pro model, and to set the delta peak, you just have to scroll using the A/B Select button until you get to the mV setting. Then use the up and down arrow to select the setting you want. Do you have the manual for your charger? I'm sure it will explain it there or maybe check MRC's website.

 

[Revo Rancher]

If you have the MX-3 Tx it may have come with a Rx that has BES. If it did, forget what yoru batt pack is reading. The BES will control the input to the Rx.

If you have the new MX-3S Tx with the full synth Rx, most likely you do not have a BES circuit board on the Rx and you will need to watch your voltage.

 

[bigfreak]

This thread is real old and stinky. I thought Wardo came back... I donno if this guy even cares anymore but I'll toss my 2 cent into the ring.

I have a 5 cell hump pack... so that's 6 volts right? Well, pull it off the peak charger and it says something like 7.4 or something like that. It just seems to be how these batts work. Heck even my gelcel is 12v but comes off charge at like 13.4 v.

So yeah if you put the volt meter on your 5 cell pack and it reads 7.2, don't worry about it. Now, if you have a 6 cell pack, that thing may come off charge at 8+ volts (not a good idea to stick onto your RX).