Big feet

Hi all,
I am moving over to the dark side with a JR 2.4G system.
I have followed the threads regarding 'brown out' due to high current causing low voltage from standard 4.8v batteries.
As such I feel a larger battery with a voltage regulator is the way to go.
I am unsure as the the current capacity required for use in my jets.
I have both a Boomerang Elan and a SM F18.
Would [link=http://www.realraptors.co.uk/shop/index.php?main_page=product_info&cPath=90&products _id=3771&zenid=so1127o84nmdi573tuua723tr3]this[/link] fit the bill?

Thanks for the help.

rhklenke

My Feedback: (24)

Big Feet,

Yes, I use Fromeco regulators on many of my jets. The new Sahara regulator works very well. I typically power them with plain old, reliable, cheap 5-cell NiCD packs...

Bob

XJet

Why regulate a 5-cell pack?

Virtually all modern servos work very well at 6V-6.6V and adding a regulator to a 6V pack simply introduces another point of potential failure for no gain.

Not only is it something else to go wrong but in the case of a linear regulator, you simply end up wasting a portion of your valuable battery charge as heat.

What's more, since all regulators will cause *some* voltage drop, you're actually *reducing* the amount of headroom (safety margin) that you're providing your receiver against brownouts.

It's not atypical for a linear regulator to have a minimum drop voltage of as much as a volt or so. That means when you put 6V in you're not going to get much more than 5V out. While your battery is working well and charged, that's not a problem. However, if you lose a cell then your battery voltage may drop to 5V and thus the voltage fed to the receiver/servos will fall to 4V dangerously close to the reboot voltage if you're flying some 2.4GHz systems.

Don't waste your money heating the air in your plane with a regulator just use the 5-cell pack direct.

Or even better, invest in a LiFePO4/A123 pack and enjoy the additional benefits this new battery technology offers.

_________
When I'm not here I'm at [link=http://rcmodelreviews.com]RCModelReviews[/link]

S_Ellzey

I have been running 5 cell Nicads in my jets for over 20 years with out a regulator or problems.

With the AR9100 or JR 1222 reciever it is real easy to use the dual Nicads since the reciever is built for it, this is about as KISS as it gets. If you use two identical packs you can build a simple harness that hooks the two packs together and allows you to charge them as a single 10 cell pack, so you do not have to worry with an extra charger or taking longer to field charge. just make sure to cycle them individually once in while.

Steven

rhklenke

My Feedback: (24)

I'm sorry, but yawn... This is an old discussion. I know exactly what a linear regulator is, how it works, and what kind of reliability to expect from it. Regulating a 5-cell pack down to 5.2V or so actually reduces the current draw of the servos and RX , makes the servo speed more consistent over the discharge cycle of the pack, and keeps the equipment (that now, with FASST, actually runs at 2.7V internally) from being connected to a supply voltage of over 7V when the 5-cell pack comes off the charger.

I have NEVER had a single problem from a Fromeco regulator and with a "failsafe switch" they are more reliable than another solution with a normal switch that can fail in the open position. As far as the battery discussion, why pay more for a simple supplier of EMF? The equipment connected to it doesn't know the difference...

Bob

bigbaggy

Use a regulator for a 2s lipo system but not a 5 cell nicad. Steve is right, kiss.

SinCityJets

Get you some A123 packs and don't worry about any of it!!

rhklenke

My Feedback: (24)

Yea, but then there's the guy on the Futaba FASST thread that just lost his jet when he couldn't tell that his A123 packs weren't up to full charge...

Like I said, I've had many, many hundreds of fights on plain old quick-chargable 5-cell NiCD packs with a Fromeco regulator, so to each his own...

Bob

SinCityJets

Yea, I think making sure your packs are charged is pretty much a must with any battery set-up! That's like some people I have seen when they realize they forgot to fuel their plane about the same time it cuts out...landing will be next.

XJet

That's hardly the fault of the battery is it?

When you can fully charge an A123 from flat in just 15 minutes, they have no memory effect, and they have a cycle life of over 1,000 charges, there's simply no excuse for not throwing them on the charger for 5-minutes between flights is there?

If the guy concerned forgot to refuel after a flight and crashed with a dead-stick, would he blame the fuel?

Ehab

My Feedback: (44)

No, he would blame the turbine for not running on air only

Big feet

Thanks for the help guys.
I have not tried A123's yet, not long into Lipos to be honest.
As I have a couple of good chargers that are for lipo's, I think I will lean that way.
Funny how many different ways there are to skin a err, grape.

Cheers,