Drawing from one of two 6V 7AH series connected batteries in 12V Solar system

[mrothe]

Hi Everyone,

I was wondering if there would be any benefit in connecting to one of two 6V 7AH series connected batteries in a 12V solar system to power my arduino board, the reason I want to do this is when I connect my arduino to the 12V the linear voltage regulator on the arduino board converts the 12V to 5V by dissipating the extra 7V as heat, which is very inefficient. I have attached a picture to explain what I am considering but am not sure if this would help or not, would the two batteries eventually reach an equal charge if more of a load is drawn from one of them?

Thanks for taking the time to read my question and I would appreciate any advise.

mrothe


BatteryConnection.png

[Mike90250]

It is such a simple way to destroy BOTH of your batteries. You kill one by discharging it, and the other one by overcharging.

Just don't do it.

[Rainwulf]

You are much better of getting a small switch mode buck converter to step down the 12 to 5 volts directly, bypassing the linear converters entirely.

http://www.ebay.com/itm/Mini-3A-DC-DC-Converter-Adjustable-Step-down-Power-Supply-Module-replace-LM2596s-/371451400661?hash=item567c3a91d5:g:xcUAAOSw0HVWCVzf

[mrothe]

Thanks for advice

I figured it might be a bad idea, that's why I asked. I will probably go with the switching regulator , I have used the 3.3v version before on some msp430 processors and they worked good, the only problem with using these on arduino uno boards is they are a bit tricky to swap with the factory smt regulators on the new uno boards, which begs the question at what point do I make my own board instead of modifying off the shelf arduino. I was just hoping I could get away with my quick and dirty plan but no such luck ☺.

Thanks for the quick responses

M Rothe.

[Rainwulf]

Just ignore the regulator on the board. The 5 volt outputs on the arduino can also be used as inputs, and you can power the entire board with your shield/pins.