I need help selecting a battery!
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Please be positive and constructive with your questions and comments.
- inevu
- Posts: 39
- Joined: Mon Feb 06, 2012 5:22 pm
I need help selecting a battery!
Hey guys! So I am building this robot and I need a battery to power it. I need to get the smallest battery possible no matter what the price is. I need a battery that would get me 6V and 5A constantly for about 20 minutes. So what battery should I get? Thank you very much for your help!
- adafruit_support_bill
- Posts: 88093
- Joined: Sat Feb 07, 2009 10:11 am
Re: I need help selecting a battery!
I'd suggest a 5xAA NiMH pack.
- inevu
- Posts: 39
- Joined: Mon Feb 06, 2012 5:22 pm
Re: I need help selecting a battery!
Awesome! How many MAH do you suggest I get? Thank you very much!
- adafruit_support_bill
- Posts: 88093
- Joined: Sat Feb 07, 2009 10:11 am
Re: I need help selecting a battery!
In theory: 5A for 20 minutes is 1667 mAh. But you will want a bit of a safety factor because:
- 1. The actual delivered mAh is dependent on the discharge rate - (and 5A is high)
2. You want to make sure you don't start to fade before the 20 minutes are up
3. Manufacturers often inflate the capacity ratings.
- philba
- Posts: 387
- Joined: Mon Dec 19, 2011 6:59 pm
Re: I need help selecting a battery!
Can you live with 7.4V? LiPos will give you about twice the power density over NIMHs (or half the size). Plus LiPos have a really wide range of capacities, sizes and shapes. A 2 cell LiPO has 7.4V as it's nominal voltage and you can get them in really high capacity and/or really high discharge rates. If you are driving a motor, the higher voltage shouldn't be a problem.
Please be positive and constructive with your questions and comments.