Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Batteries & Chargers => Topic started by: Ginger64 on March 10, 2016, 08:46:26 pm

Title: Do I. Or. Don't I. !
Post by: Ginger64 on March 10, 2016, 08:46:26 pm

Well got my new nimh battery packs 7.2 volts 5000 mah.  And my new 4.8 x2600 mah for receiver Now do I cut the red wire or don't I.  I know if I add the receiver pack I have to. But should I try my boat with out it   Now I've got 7.2 instead of 6vlt 4 mah as main battery. Will it run long with receiver battery or not. Any advice.

Title: Re: Do I. Or. Don't I. !
Post by: malcolmfrary on March 11, 2016, 09:17:18 am

As has been said on many previous threads, if you are using a separate battery for the receiver, and the ESC has its own BEC, the red lead on the RX plug must be disconnected. 
DO NOT CUT IT.
The pin can be winkled out of its housing and taped back in a tidy manner.  That way, should the need arise, you can replace it back where it came from.

Title: Re: Do I. Or. Don't I. !
Post by: inertia on March 11, 2016, 10:56:17 am

In answer to your first question, no - use the method Malcolm has described, like this:
http://www.action-electronics.co.uk/pdfs/Disabling%20BEC%20ESCs.pdf (http://www.action-electronics.co.uk/pdfs/Disabling%20BEC%20ESCs.pdf)
To your second, suit yourself. I wouldn't bother. The risk is that using one of the 7.2v batteries to power the Rx via a BEC will run it down faster than the other one. This will reduce the running time and could adversely affect the handling. Waste of a new 4.8v battery pack if nothing else.
To your third, see above.
DM

Title: Re: Do I. Or. Don't I. !
Post by: essex2visuvesi on March 11, 2016, 11:13:24 am

Another option:-


Use a short servo extension wire between the Servo & RX and cut out the positive feed line.

Title: Re: Do I. Or. Don't I. !
Post by: Ginger64 on March 11, 2016, 07:59:22 pm

Well I've pulled the red wire from the plug and added the rx batt pack and run the boat on the 7.2 batt. No probs. no cutting out. And boy it's fast. But I'm goin to keep it slow to save battery power. Thanks again people. Sound advise as always.

Title: Re: Do I. Or. Don't I. !
Post by: sigfortunata on March 25, 2016, 03:23:04 pm

I run my boat with 2 x 2S 8.4v lipo running a ESC and motor each. 
 
One of the ESC's has the red BEC wire disconnected. 
 
Having one of the batteries run the receiver make virtually no difference to their discharge rates and run time.

Title: Re: Do I. Or. Don't I. !
Post by: Netleyned on March 25, 2016, 04:32:29 pm

Where do you buy 8.4v lipos???


Ned

Title: Re: Do I. Or. Don't I. !
Post by: essex2visuvesi on March 25, 2016, 04:37:14 pm

A 2S Lipo is 7.4V nominal, but fully charged kicks out 8.4V

Title: Re: Do I. Or. Don't I. !
Post by: sigfortunata on March 25, 2016, 05:30:57 pm

In a world where I am poor at maths Ned  :embarrassed: