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rbrown7713

Milliamp size of Lipo battery and length of time it lasts?

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Could someone tell me what is the best capacity in milliamps for a Lipo battery and the length of time it will run?  I have been using 5200 mah, NMH batteries and am not having much luck. They don't last very long. Please help, Bob, any info. would be good. Bob.

Edited by rbrown7713
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What is the voltage of the battery pack that you are using?  Also, how long are they lasting?  What engines are you running and how many on the battery and are you running smoke?

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The NMh batteries that I am using are 5200mah. and  7.2volts times 3 should be 21.6, but when they are fully charged, I have checked the voltage and have seen up to 25Volts.  I haven't chosen a voltage to run, but I understand that when they discharge to 15 volts, the engine shuts down.  I would rather ask you what is the proper voltage and milliamp rating for a long run, I don't know.  I haven't bought them yet. What would be your recommendation?  Bob.

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If using 7.2v battery packs in series, then you are down to 1733mah at 21.6v.  (5200 div by 3) .   

 

I recommend getting a single battery pack (suggest 22v) that is 5000mah or larger.  If the batteries aren't lasting very long it could be related to smoke unit use, inexpensive batteries (quality) or due to age.  

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Ray

If he has 3 5200ma batteries in series, they will still have 5200ma capacity.

Putting them is series will not reduce the 5200 ma capacity.

The voltage will be increased, but the ma capacity will not change.

Tom

 

Here is an example of batteries in series:

Series Connection

Portable equipment needing higher voltages use battery packs with two or more cells connected in series. Figure 2 shows a battery pack with four 3.6V Li-ion cells in series, also known as 4S, to produce 14.4V nominal. In comparison, a six-cell lead acid string with 2V/cell will generate 12V, and four alkaline with 1.5V/cell will give 6V.
 

Serial connection of four NiCd or NiMH cells

Figure 2: Series connection of four cells (4s).
Adding cells in a string increases the voltage; the capacity remains the same.
Courtesy of Cadex

 

Tom

 

Edited by grsman
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Thanks.  The first set of batteries that didn't perform well, were cheap ones and those are suspect.  I bought some new ones, and they seemed to perform better, I will do some more inspecting, thanks again. Bob.

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Quality of the cells and where the cells are made.  Batteries that only last a year or less you find out you got poor quality battery (w/poor quality cells).

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Well what determines quality and where should they be made can you elaborate, don't want to buy some a wait a year to find out if they are any good

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Buying batteries isn't really that clear cut.  Often it is price that is the biggest indicator but it still isn't a guarantee.  Generally you can say that battery cells made in China are more likely to be avoided but that isn't always for sure either.   Then you run into sellers saying their cells are from non-Chinese source only to lie about it.  Bottom line is you need to buy from a reputable source.   

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I purchased some inexpensive Chinese Li-ion cells on Ebay to make up battery packs. They have protection PCBs installed. They worked quite well and are still going strong.

I also purchased a 14.8v 5000ma Li-ion pack from a reputable US seller. It failed after what I consider a short time. I found two defective cells after inspection.

Batteries can be very difficult to deal with. Sometimes you have to pay your money and hope for the best.

I think a good quality charger will go a long way to keeping batteries healthy.

Tom

 

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If you buy from a reputable company wouldn't they try to work with you to fix or replace them. 

I'm not sure if we can post sellers here....:Thinking_Face_Emoji_large(24x24):

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