Rfabbre

My Feedback: (6)

I have a Sig 3D Mayem with a Saito 91-not really enough power. I am in the process of converting to a DLE20.

The Mayhem uses 5 analog servos which I plan to continue to use, Do I need 2 battery packs like I use on my 50cc gassers or is 1 sufficient?

If one pack, it would be a 4 AA Sanyo Eneloop NIMH pack.

Thanx in advance for your thoughts.

MetallicaJunkie

the eneloop 4.8 will work fine, they are damn good battery packs!


but if you do want to run just one battery pack it can be done..... this device will filter out any interference, plus if you are running a higher that 6 volt battery it will regulate it to the proper voltage for your ignition http://www.syssaaircraft.net/cart/pc...5&idcategory=2 i like that one

this one seems ok too http://www.troybuiltmodels.com/items/WRCIBEFV2.html

ahicks

My Feedback: (2)

I wouldn't try it with AA NiMh. One pack will work - as long as it's not an AA NiMh. Just went through this proving it to myself though I was using some pretty big servos. If your results are like mine, you'll very likely run into brown out issues, even if you add a cell to bring it up to 6v, or running the power through an additional voltage tap and switch (which did help).

What I didn't know was that the NiMh are at the bottom of the totem pole when it comes to producing enough amperage to get the job done in this application. You can go to sub-c NiMh and it'll work, or any other popular type. Just stay away from the AA NiMh.

Tired Old Man

My Feedback: (1)

Might want to consider an A-123. At 6.6v while using a step down for the ignition it has all the amperage you need and can be recharged at the field in 15 minutes or less.

TimBle

+1

pilotpete2

+2!
Just add a Wike, or other proven IBEC, and a 2S 2300mAh A123 pack, and you're good to go[8D]
Pete

repinfl

My Feedback: (40)

Anyone know if the FlightPower FT8AVR Voltage Regulator, which has two input and two output leads and states in instructions:

"The FT8AVR can be powered by two batteries for
maximum duration. To maximize the current of the FT8AVR,
plug both output leads into one receiver. This will allow
for 8-10A of current."

could be used to power the RX with one output lead and the ignition with the other lead using two batteries?
Surprisingly their tech. support would only say "I think so". Thanks!

Tired Old Man

My Feedback: (1)

You would need to step down the voltage to the ignition. Plugging two batteries into a receiver is nothing new, nor is plugging two leads from one battery into a receiver to obtain higher available amperage levels.

However, there are products intended to fit inline with a receiver that will reduce voltage and isolate the ignition from the flight systems, providing RF safety and single battery capability to the aircraft. I do not use them but many do. I'm certain a few will step in and post information appropriate to their products. Jody at Valoley View RC would be an excellent information source for such a product.

You have a very good option of using a single high capacity battery to handle your electrical needs. You should investigate it further. Your plane is not of a size or at cost level where battery redundancy is a factor. Th right batteries will provide a lot of flying time and considerably more amperage than what you had noted in your original post. The Eneloop would make a great ignition battery, but a very poor flight battery.

repinfl

My Feedback: (40)

TOM This is a voltage regulator I am talking about. It has two input leads and two output leads intended for using two batteries
that would plug into the RX to max current. I am wondering if I can plug one Batt. into the RX and one into the Ign.

repinfl

My Feedback: (40)

It can be found here:

http://www3.towerhobbies.com/cgi-bin...&I=LXVDB1&P=ML

a1pcfixer

My Feedback: (7)

This is what I use on both of my DLE20 powered models;
MPI Voltage Regulator MK3 Adjustable [MPI-ACC135]
http://rcbuyerswarehouse.com/mpivolt...djustable.aspx

Specs on it appear a tad better than the FlightPower, but outwardly similar.

I'm running a 2S1P TBM Ultra Power Li-Ion 2600 mah pack with JR, Deans and Balance plug
http://www.troybuiltmodels.com/items/AH2CDLIION.html

That single Li-Ion battery feeds into the MK3 regulator, then I feed one line off that to my ign, the other to my rcv.

I too agree that the Enloops while the best of that size for NiMh are great, I'd NOT use them for this sort of a combo.

BTW.....in the fwiw dept;
Enloop has upped their suggested number of charge cycles on their batteries from the former 1000 cycles to a 1500 cycles.
Not sure about pre-made flight packs though. Hard to say when they were made up. This is news in the past couple months or so.

captinjohn

A1pcfixer, what is the ways you can charge the Enloops pacs? I used a Sirrus smart charger but the batteries felt a little warm???? If anyone else know any tips....chime in please. Thanks Capt,n

a1pcfixer

My Feedback: (7)

I'm using a simple/basic 4 cell AA charger I got from K-Mart.
But, yep, they do get warm.....just watch them & remove when done.

captinjohn

Thanks for the reply.....Capt,n

Tired Old Man

My Feedback: (1)

Eneloops should be charged at a very low rate. If they are becoming warm they are being damaged. A 2000 ma Eneloop pack should be charged at roughly .4c. Never fast charge an Eneloop battery. Matter of fact, if you are charging a NiMh battery and it is getting warm you are charging it too fast, UNLESS, it was specifically made to accept a fast charge process. Most are not.

Ernie Misner

Tired Old Man is absolutely right. However keep in mind there is a difference between being barely warm and getting overly warm or hot. When fully charged even with the little 50mah wall wart charger, they will be barely warm the next morning when fully charged.

Thanks,

Ernie Misner

a1pcfixer

My Feedback: (7)

Yep, hot is very bad, warm is acceptable on Enloop's.
Same in discharge mode.

hemant

I have a 1/4 scale Bucker Jungmeister weighing in at 12# with 5 Futaba 9202 servos and DLE 20 gas engine. It is setup with one 2100mah NiMH battery to a Futaba 8 channel 2.4 receiver and the ignition is connected through an Syssa IBE to the receiver. Normally this plane use approx 75mah per 10 minutes flight with a Saito 120. I plan on flying sport/scale with the model. Any concerns on this setup with one battery?

a1pcfixer

My Feedback: (7)

If your NiMh is a 4 cell, bad idea. The added drain from the ign could possibly
drop the voltage down to where your rcv does a re-boot.......crash?

A 5 cell is better, IF your IBE drops the voltage fed to the ign to a range of 4.8 - 6.0 volts.
A 5 cell straight to the ign is a very bad idea.
Better to go with 2 batteries, a 5 cell NiMh to rcv, and 4 cell NimH to ign.

Most running a combined ign + rcv off 1 battery are doing so with Li-Ion -or- A123/LiFe batteries.
Both give a far better flat line steady state voltage until nearly empty. NiMh's start dropping off right away.

ahicks

My Feedback: (2)

I would say yes, big concern. This is very similar to the setup I was describing with brown out issues earlier in this thread. It's about the lack of amperage available from AA size NiMh batteries - and adding a cell and/or a second voltage tap and switch won't fix it! I tried it! AA sized NiMh are a BAD PLAN for a single battery pack setup on a gasser!

What you're going to run into is at higher throttle settings and with a strain on the servos (as in knife edge for instance), there's not going to be enough amperage/power left over to power the receiver, thus producing all sorts of wierdness, and a very good chance the plane will go in due to loss of control once the chain of events is started.

That sequence went something like this on the one that taught me about this problem: engine ignition power is cut due to receiver signal loss, removing the amperage drawn by the ignition from the circuit, which restores adequate power to the receiver, which then reboots, restoring control of the plane, giving you a shot at recovery - maybe. Not cool at all! I found the chances of this sequence starting are increased greatly as the battery was worn down - like maybe starting with the second or third flight.

I don't believe the fact that these AA sized NiMh batteries SUCK when compared to any other battery type when it comes to producing amperage available to the flight pack is widely understood. I know 2 of these packs will work, I'm told sub c NiMh and Nicads will work, and of course the lithium based batteries will work.

Edit: Just wanted to note that the A9 radio was giving me a single beep on occasion when this was happening, indicating low receiver pack voltage. That, and some EXPERT advice is the ONLY way I was able to figure out what was going on here.

a1pcfixer

My Feedback: (7)

I was too lazy to give him the extended info like you did.
So he got my condensed version.[8D]

repinfl

My Feedback: (40)

This is what I use on both of my DLE20 powered models;
MPI Voltage Regulator MK3 Adjustable [MPI-ACC135]
http://rcbuyerswarehouse.com/mpivolt...djustable.aspx

Thanks for the info. It does look very simular to the FlightPower.

BarracudaHockey

My Feedback: (11)

I'd personally do away with the potential failure point of a fancy regulator.

A123 battery with 2 leads, one to the reciever through a heavy duty switch, one lead to a step down diode then a heavy duty switch to the ignition.

Charges fast, has plenty of power delivery, and you dont have to dink with a regulator.

www.wrongwayrc.com has everything you need including an A123 charger if you need.

a1pcfixer

My Feedback: (7)

True, but not everyone has a charger capable of balance charging A123/LiFe batteries.
However, many do have chargers capable of charging Li-Po's and Li-Ion batteries.

It's a matter of personal choice.

av8tor1977

My Feedback: (6)

Say TOM, I thought you were unilaterally and unequivacably AGAINST using one battery in an airplane?

AV8TOR