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Old 02-16-2008, 10:11 AM   #1
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Default battery confused

I am trying to find a battery. I have been looking and searching for sometime now and still don't understand what i need. I have a 55t motor CC Sidewinder on the way. I would like something that will last for 45 min or longer. I have about 80 to 100 to spend on battery and charger. any suggestions. minh lipo 1500mah 4500mah?
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Old 02-16-2008, 10:37 AM   #2
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It will vary from truck to truck, but a 2/3a 1500 pack should go 45min. I would not run anything heavier than that in a crawler. Don't cheap out on the charger, they can be versatile enough to stay with you for years no matter what batteries you choose. I run a thunder power 1320mah 2 cell lipo, not expensive at all, runs about an hour, but has a marginal "c" rating. Also the trend is 3 cell lipo's but my rooster won't do that. Your sidewinder will handle a 3 cell., and I bet if you check holmes hobbies you could get a good lipo charger cheap. Also check cheapbatterypacks.com.
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Old 02-16-2008, 10:41 AM   #3
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So i should go with a lipo
for a lipo what shouldi look for?
What does 2/3a mean?
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Old 02-16-2008, 10:57 AM   #4
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2/3a cells are nimh batteries. About the same size as a lithium pyle camera battery. They are completely different than lipo's.Just check the venors here to get an idea of what you're looking at. If you get 2/3a packs get elite 1500 cells(thats a brand).
Lipo,s are great for wieght reduction and more "punch". Look for a 2 or 3 cell pack with the highest "c" rating. Again check the vendors here, contact them with questions, or search this forum for more information than I can give you.
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Old 02-16-2008, 11:12 AM   #5
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thank you
and i one more question what's the diff between 2 and 3 cell batteries
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Old 02-16-2008, 04:06 PM   #6
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Quote:
Originally Posted by BigKRI View Post
thank you
and i one more question what's the diff between 2 and 3 cell batteries
I am going to assume this question is stemming from the "2/3A" you read in Bastards' posts. This is not the quantity of the cells in the pack, it's the physical size of the cell itself. A 2/3A cell is exactly that....two thirds the size of a full sized "A" battery. This means it's the same diameter as an "A" battery, but is only two thirds the length...which means it's one third shorter than the full length "A" cell.

The number of cells in the pack you run is really based on several things. Frist is which ESC you're running because they all have a maximum cell count they are safe to handle. Second is how much wheelspeed you want in relation to how your rig is geared. Primarily the more voltage you have, the faster the wheelspeed...so long as you're using quality cells with a high discharge rating. Third would be how much physical weight you're willing to add to your rig just in the battery pack. Fourth would be how much room you have on your rig to fit a pack.

To figure out voltage of the pack, the rule of thumb is 1.2 volts per cell. Some have slightly more (higher quality cell) and others just barely cut it (low quality cell). For example, an 8 cell pack will yield about 9.6 volts...no matter what size the cell is.

In terms of the cell capacity (mah), get the highest you can in the cell size you're after. The Elite 2/3A cells are 1500mah, and as far as I know, that's the highest capacity 2/3A cell out there.
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Old 02-16-2008, 06:23 PM   #7
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Remember, lipo packs are 3.7v per cell. Offroader5 was explaining details of nimh cells. So if you are looking at a 11.1v lipo pack its three cells. If you are looking at a nimh pack that is 7.2v it is six cells.
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Old 02-17-2008, 11:03 AM   #8
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I'd save up a little more for a nice charger. Also, do you need an AC/DC charger, or will something that is straight DC work? Check out Hyperion's stuff. Good chargers, but they'll cost you a little more. With regards to batteries, I just opted to go Lipo, as the batteries aren't much more expensive and they don't drop in voltage across a run. I'd go 3s, which will give you more power and wheelspeed, and more flexibility in which motor you run. If you opt to go with nimh, a pair of 8 cell saddle packs and a Duratrax Digital Phirahna won't break your budget by much.
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Old 02-19-2008, 05:44 PM   #9
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thanks for the info guys. Sorry it took me so long to get back to you been working a lot. I am starting to understand what you guys are saying. I am getting the sidewinder (hasnt' come in yet), and people are saying some about getting a bec? Is that necessary?
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Old 02-19-2008, 07:44 PM   #10
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http://www3.towerhobbies.com/cgi-bin...?&I=LXSWL3&P=M

I would suggest it for under $25.
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Old 02-20-2008, 11:04 AM   #11
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A 1500mah NiMH set-up will last you a good one hour or more, depending on your throttle finger and the servo you use. I'm going to assume you're new to electric rc, so would suggest starting with NiMh batteries, but buying a good charger compatible with both NiMh and lipo.

I haven't seen what your set-up is, so running a bec may not be necessary. However, as Miller Time points out, for the price, it definitely doesn't hurt, whether you need it or not.
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Old 02-22-2008, 02:42 AM   #12
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Quote:
Originally Posted by BigKRI View Post
thanks for the info guys. Sorry it took me so long to get back to you been working a lot. I am starting to understand what you guys are saying. I am getting the sidewinder (hasnt' come in yet), and people are saying some about getting a bec? Is that necessary?

i'm not sure what the bec is or does so wanna clear me up on that please im not a newb but feel like one now lol........my setup is a 65 turn lathe with a 6 cell 2/3a 1400 ibc battery a jr 9000t servo and a futaba MC230CR speed control do i need the bec or not really ?
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Old 02-22-2008, 07:34 AM   #13
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BEC stands for Battery Elimination Circuitry. Short version- in the begining (lol) speed controls were manual, not electronic. They were ceramic plates with metal contact bands across them, and a metal sweep arm mounted to a throttle servo. The servo would move the sweep arm across the speed controller, and each band on the ceramic plate would equate to a different level of throttle. Because there was no electronics involved, the RC's receiver needed a separate battery pack for power. This was usually a small plastic pack of 4 AA's.

Later electronic speed controls came out, increasing the effeciency and smoothness of the throttle curve by having many more steps of throttle than a manual, which usually had around 6 steps. Some time later, the electronic speed controls (ESCs) started to include Battery Elimination Circuitry, or BECs. This meant that the ESC diverted a small amount of electricity from the RC's rechargable batteries to the receiver, to power it and the servos. This is almost standard today in electric RCs, although the BEC output varies from one ESC to the other. 6v is what most modern radio gear wants, but some ESCs supplied only 4.8v or sometimes less. The Mamba Sidewinder as the original poster was discussing, won't provide 6v.. actually I'm not sure of the specifics on that model, I believe that is only true when using a 3s lipo? Someone confirm..

Anyway, the Futaba MC230CR that you are asking about does have a 6v BEC built in, so no additional unit is required.
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Old 02-22-2008, 08:06 AM   #14
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This page has lots of good info on batteries etc.
http://www.cheapbatterypacks.com/?pgid=faq&sid=662924

Like some have said before,,,,, a good charger is a good investment. It will help you care for your batteries properly (link above) and save you money in the long run.
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Old 02-22-2008, 08:47 AM   #15
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I have a Teken Rebel 2 and mostly you guys are talking about mambas and novak, so whats a good battery for the TR2?
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Old 02-22-2008, 01:46 PM   #16
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I have a JR 645mg 55t motor and sidewinder. Mine as well hook up a bec right? couldn't hurt? 1500 NiHM elite 2/3 cell battery pack will do with a MiHM/lipo charger?
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Old 02-26-2008, 01:57 PM   #17
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what is the diff between ac/dc charger
i am going to look for something Nihm/lipo i figured i'd start with the Nihm.
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Old 02-26-2008, 03:28 PM   #18
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Do you mean what is the difference between a DC only charger and an AC/DC charger, or what are the differences between charges overall?

If you mean the first, it's the power input. DC only needs to hook up to either a car battery (as in full size car, not RC..) or you can get a DC power supply. AC/DC can do this or plug into a standard wall socket. I'd suggest getting AC/DC charger - they are usually a bit more expensive, but generally cheaper than an DC charger plus power supply.
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Old 02-26-2008, 03:43 PM   #19
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thanks miller
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