Microgyros
You are correct, I'm guilty as charged (Ho Ho).
After reading through the other thread I think I owe some explanations, after all you guys and gals did help me.
my knowledge of electrics is second to none, ie just below none.....
[size=78%] I [/size]wanted 6v of power to give maximum torque to my 4 winch servos (not 4.8v)[size=78%]
my receiver takes up to 6v input
a fully charged receiver pack can go above 6v so therefore it's best to have a stand alone BEC to regulate the voltage and not exceed the 6v.
the BEC needs to be 0.5v above the dropout voltage (just quoting what I've read, I don't claim to have understood this at the time) so by adding two packs in series I get 12v dropped to exactly 6v by the BEC and enough power for long enough to power all my winches. It works!
If I plug my 6v pack straight into my receiver it's above 7.5v when fully charged and could blow something hence the need for a stand alone BEC.
With a stand alone BEC I need more than 6.5v so that's why I wanted 2x 6v packs which give 12v and is subsequently dropped back to 6v. WHY didn't I just buy a 7.2 or 8.4v pack? WELL firstly I didn't know if that would fix my problem, secondly I have a battery tray made to fit the packs and thirdly I have 2 packs here ready to fit instead of paying money for a new battery and then waiting and having to build a new battery box.
I wanted a second indipendent battery to power an ESC and motor in case of emergency.
I wanted this battery to stay inside the boat as long as possible without the need to charge it. It had to be powerful enough to power the brushless motor (11 to 18v) So it had to be a lipo and on a system that was not draining even a tiny bit of power until a switch was flicked.
Why a lipo I can hear? They hold charge and they are lightweight and they have the discharge capability to power a brushless motor.
I thank all you guys for trying to help me and I apologise for the headaches
BUT what is obvious to you guys is sometimes very confusing for people with no understanding of electrics.
Nowhere on my BEC instructions does it say 'when supplying 6v from this BEC you will need more than 6.5v or it will stop working and only maybe power 1 servo. It does however state that it works from 4.8v up to 26v. Now I've seen a device which plugs into a 12v cigarette lighter in a car and changes it into enough volts to power a telly and thought maybe a BEC works similar to that
Now it's me who's at a loss because I can't understand why anyone would plug a fully charged 6v pack (possibly charged to 7.5 v) into a receiver that could blow if over 6v is plugged into it.
BUT at the end of the day I'm still happy, very glad of all your help and still learning 'the black arts'
Now if any of you guys need any help building I'll be only too glad to help...... Thanks again, until my next electrical problem......... A happy U2
[/size]