Battery questions

[Cat966c]

Hi all! Been away for awhile. Anywho, I'm at the battery stage of my project and I need help (surprise). So I'm running a 12 volt rated pump and was thinking of getting an 11.1 volt battery, but the dimensions of it are too big. So I was wondering if I can use a 7.4 volt and still get decent power from the pump?
The pump is rated at 150psi at 12 volts.

[Rimrock]

Hi all! Been away for awhile. Anywho, I'm at the battery stage of my project and I need help (surprise). So I'm running a 12 volt rated pump and was thinking of getting an 11.1 volt battery, but the dimensions of it are too big. So I was wondering if I can use a 7.4 volt and still get decent power from the pump?
The pump is rated at 150psi at 12 volts.

150 psi at 12V is a low rating initially. E.g in a excavator 300-400 psi is used to get a decent power. On a dozer it's more a matter of moving the dead weight of the blade and so on, so not as critical with the pressure as an excavator. you might get things moving at 7.4V, but not have to big hope of things moving fast) but it's no problem to give it a try, if you already got a 2S battery at hand.
There are lots of different sizes lipo 3s batteries out there, e.g ebay, would advice you to search for a suitable one.

[Cat966c]

How about if it was an 11.1 volt battery? I've found one on eBay that's pretty compact

[Northern Farmer]

Traxxas 11.1 1400mah lipo is fairly small.

https://www.amazon.com/Traxxas-Battery-Connector-1400Mah-3-Cell/dp/B005FUKPLO/ref=sr_1_1?s=toys-and-games&ie=UTF8&qid=1495123182&sr=1-1&keywords=Traxxas+1400+battery

[Rimrock]

How about if it was an 11.1 volt battery? I've found one on eBay that's pretty compact

That's the one to go for, that is the LiPo batteries with 3 cells, named '3S', mostly used these days for 12V setups. They are about 12.5 V fully charged, and one will typically recharge them when they have dropped to about 11.1V. A charger that is prepared for LiPo batteries is needed. And LiPo voltage alarm is needed, to hook up to the battery. If dropping the voltage bellow about 11V regulary, the lifetime of the battery will be relatively much reduced.

[trucker1970]

I just bought a 10 cell 12v 2500mAh as a second battery and although it came in the wrong shape because I didn't see anything other than FLAT as an option I was able to get it to the configuration I needed and made it fit. It was $82.50 delivered... no clue if that's a good price I had a hard time finding one.

[trucker1970]

http://exceltruck-shop.fr/epages/3d8e5f80-7bb6-4863-8ad5-323057f96271.mobile/fr_FR/?ObjectID=231242