Model Boat Mayhem

Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: Bernhard on September 30, 2011, 08:32:04 am

Title: battery connections series. help
Post by: Bernhard on September 30, 2011, 08:32:04 am
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i will like to have to Lipo 7.4   in series... to give 14.8v....bot...i have a sound mondule and a waterpump...there only use 7,4 volt...and i don't have eny more space fore a extra battery,,,what can i do,,,can i take the power from 1 off the battery?...or what else to do......?
Thanks
Regards Bernhard
Title: Re: battery connections series. help
Post by: andyn on September 30, 2011, 09:28:24 am
I'm afraid you're going to have to use smaller batteries, unevenly draining li-po's in series is generally not a good idea.

Andy :-)
Title: Re: battery connections series. help
Post by: dreadnought72 on September 30, 2011, 10:46:00 am
Look into voltage regulators, Bernhard.

I'm certain there's a solution for you which would allow you to tap into the full voltage and output the voltage you need. Are you handy with a soldering iron?

Andy
Title: Re: battery connections series. help
Post by: malcolmfrary on September 30, 2011, 10:55:10 am
Both sound module and water pump will probably work to a range of voltages - it should be possible to get and fit a voltage regulator to derive the required voltage from the full supply, depending on the requirements of the extras you intend to power.  If they need a lot of current (more than 1A in this context dropping 7 volts is a lot), using three smaller batteries may well be the only way to do it, two in series for drive, the other for the auxiliaries.  Like Andy says, uneven discharging is a bad idea.
Title: Re: battery connections series. help
Post by: Bernhard on September 30, 2011, 04:34:18 pm
Thanks......ok.......... i have to stay with the 2...and try to get a small battery to the sound-and pump.  this is the pump



ated voltage:   6V DC
Rated current:   0.23A 
Capacity:  2.2L/Min (35GPH)
Pump head: 0.6M
Noise: <=35dBA/10cm
Working temperature: -35C ~ +80C
Service life: 26000 hours up
Motor:  DC brushless motor               
Pump:  Centrifugal pump
Weight: 130g (4.6 oz)
Size: 59 x 41 x 33mm  (2.3 x 1.6 x 1.3 inch)
Cable length: 280mm (11.0 inch)
 

Regards Bernhard
Title: Re: battery connections series. help
Post by: nick_75au on October 01, 2011, 10:41:44 pm
A BEC is your best answer there are many different types that will convert 14.8 down to 6 volts, will the sound module run on 6 volts? as most BEC are 5 or 6 volt output.

An example of the many out there

http://www.hobbyking.com/hobbyking/store/__3735__HXT_UBEC_5_6v_output_5_5_23v_Input.html (http://www.hobbyking.com/hobbyking/store/__3735__HXT_UBEC_5_6v_output_5_5_23v_Input.html)

The lead you have pictures in your first post is a parallel lead not a series lead ;)

Nick
Title: Re: battery connections series. help
Post by: NickKK on October 02, 2011, 12:52:35 am
How god are you at electronics and a soldering iron ?

http://www.hobbyprojects.com/dc_theory/series_parallel_batteries.html

http://www.discovercircuits.com/DJ-Circuits/9vto4v.htm


The foirst is a usefull explanation of batteries in series and parallel... the next one is a circuit diagram of how to halve a voltage drop over a circuit put 14v in and you get 7v out...

Or you could just buy one from maplins
Title: Re: battery connections series. help
Post by: Bernhard on October 03, 2011, 06:49:00 am
Great Many Thanks

Bernhard