Lipo's

[mt3]

I have recently bought several e-flite 150mah 1s 45C batteries, looking to purchase more but not necessarily the same brand. Is there a formula/guide as to how much more capacity you can go up to for any given size, for example could I use a 250/300 mah battery of the same physical dimension?

If it helps these are to be used on a e-flite nano cps. I have noticed a big price difference on the batteries from different manufacturers so was looking to buy at least 6 for now, as I can buy 2-3 of these for the price of 1 from e-flite.

[waveydavey]

Yes you can as long as the weight isn't significantly different. Should mean longer flight times but sometimes it becomes a game of diminishing returns where the weight offsets the capacity. I would say you'd be fine though

[Grumpy]

I have recently bought several e-flite 150mah 1s 45C batteries, looking to purchase more but not necessarily the same brand. Is there a formula/guide as to how much more capacity you can go up to for any given size, for example could I use a 250/300 mah battery of the same physical dimension?

It would be almost impossible to get genuine 250mAh/300mAh batteries that were the same size (in all dimensions) as a 150mAh battery. Pretty much inevitably they will be larger and significantly heavier. Logic tells you that they should be close to double the weight (they all use the same technology after all). The heli manufacturer generally arrives at a certain battery size because it gives the best compromise between performance and flight duration. A small increase in battery size is generally ok (say 20%) but if those batteries are approaching double the weight then expect a noticeable hit on performance of the heli.

On the other hand.... It's not unknown for some 'non-name' manufacturers selling on eBay and similar to artificially inflate the rating of batteries.. For example they might take a 150mAh battery, stick a 250mAh label on then sell it for an inflated price. If the battery is physically the same dimensions and weight as a 150mAh then that would be my suspicion.

[feathering]

If it helps these are to be used on a e-flite nano cps.

Something to keep in mind is that the motor on the ncps is brushed. As such the motor may not like the extended flight times together with the weight increase.

That being said these motors may fail even if one is extra careful with them so perhaps it is best not to worry about it.

[mt3]

I have decided for now to keep with the standard e-flite batteries and just ordered some more in the Boxing Day sale, now have six in total. At these prices due to small size of battery, for now cost is not a major concern, although it will be as I get to use larger batteries.

Hopefully as and when I progress to larger models I will have more knowledge about these batteries and their usage but thank you for the advice above.

[Grumpy]

I thought that the question was about battery size, not brand?

You don't need to use the (overpriced) e-flite batteries. Other brands are fine but just watch the size and weight, plenty of manufacturers make batteries of the correct size.

[Peteski]

I have recently bought several e-flite 150mah 1s 45C batteries, looking to purchase more but not necessarily the same brand. Is there a formula/guide as to how much more capacity you can go up to for any given size, for example could I use a 250/300 mah battery of the same physical dimension?

If it helps these are to be used on a e-flite nano cps. I have noticed a big price difference on the batteries from different manufacturers so was looking to buy at least 6 for now, as I can buy 2-3 of these for the price of 1 from e-flite.

You'll find that for the same physical size, you won't get anything with more than about 180 mAh. 160 mAh is quite common in this size. Obviously has to have the correct connector too (i.e. Eflite (JST) micro). The 1S batteries in the 250-300 mAh range are a lot bigger and heavier as Grumpy says and are for use with the larger mCPX.

[mt3]

[QUOTE=Grumpy;1195821]I thought that the question was about battery size, not brand?

Yes I was originally asking about battery size in terms of capacity as well as physical dimensions, as to how much bigger in terms of capacity you could go theoretically, bearing in mind weight,size and performance of heli and motor/ battery.

I appreciate that there will be no fixed formula just looking to gain some knowledge for a later date, I think you mentioned 20% in an earlier post so that will be a good starting point for future reference.

Thanks for the advice.

[KMB]

Just to throw another thing into the mix, the CPS seems to be quite fussy about the 'C' rating of the batteries and needs to have 45C so check any after market makes for false claims