Electronics, Lighting, & Gadgets - Batteries for a PondScum

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Bohh
01-08-08, 08:33 AM
Hi all,

I've made a Pond Scum and am looking at battery options now. I need 14v or there about and am looking to get it the cheapest and lightest way possible. Now, I can easily get 2 7.2v 3000mah sub-C batteries for around $30.00. However those are large. What if I had 2 packs of 7.2v 3000mah "AA" batteries. What would the disadvantage of the smaller cell size be?

Thanks a lot,

-Mike

jeff-o
01-08-08, 09:21 AM
Nothing, really. Are you sure the size and weight are comparable, though? Self-discharge on the AA pack might be higher, too.
cyccommute
01-08-08, 10:19 AM
Hi all,

I've made a Pond Scum and am looking at battery options now. I need 14v or there about and am looking to get it the cheapest and lightest way possible. Now, I can easily get 2 7.2v 3000mah sub-C batteries for around $30.00. However those are large. What if I had 2 packs of 7.2v 3000mah "AA" batteries. What would the disadvantage of the smaller cell size be?

Thanks a lot,

-Mike

There are a couple of reasons to go with the subC packs. 3Ah packs are pretty low capacity for sub-C. Battery Space has 3.3 to 4.5 Ah subC packs. More expensive but you do get a longer burn time out of them. Additionally, the packs are already connected and in a nice package. All you have to do is make the connections. With 12 AA you'll have to find several cases to put the batteries in and then you are going to be prone to bouncing them around if they are in spring cases or, if you try to put them in a water bottle, you'll have to have something insulating each cell from the next so that you don't short out cells. I did the water bottle with spray in ureathane foam once...it was a mess:eek:

kk4df
01-08-08, 01:44 PM
Hi all,

I've made a Pond Scum and am looking at battery options now. I need 14v or there about and am looking to get it the cheapest and lightest way possible. Now, I can easily get 2 7.2v 3000mah sub-C batteries for around $30.00. However those are large. What if I had 2 packs of 7.2v 3000mah "AA" batteries. What would the disadvantage of the smaller cell size be?

Thanks a lot,

-Mike
If your Pond Scum is using a 20W halogen bulb, expect to get about 1h 20m from the 3000mah batteries. I have used one of the lithium 4800mah packs from batteryspace.com