battery c rating

[Andy48]

Can I reiterate what I said at the start, and that is that a higher "C" rating does appear to equate to a longer battery life. There is probably a simple explanation for this in that you are stressing the battery far less by drawing well below its maximum current rating and therefore you get a longer life. From my anecdotal observations, the extra life expectancy is well in excess of the extra cost of getting a higher "C" rating equivalent.

[Mike Blandford]

My understanding is that lithium batteries degrade over time, regardless of whether they are being used or not. This results in the internal resistance increasing. Since a higher "c" rated battery starts with a lower value of internal resistance, it is likely to be longer before it becomes too high for the battery to perform well.

I also understand that this ageing process may be reduced by storing the batteries at a lower temperature.

Mike

[Keith Miles 2]

Posted by Andy48 on 14/01/2020 13:58:42:

Can I reiterate what I said at the start, and that is that a higher "C" rating does appear to equate to a longer battery life. There is probably a simple explanation for this in that you are stressing the battery far less by drawing well below its maximum current rating and therefore you get a longer life. From my anecdotal observations, the extra life expectancy is well in excess of the extra cost of getting a higher "C" rating equivalent.

And I think that most would agree with you. Your reasoning is entirely sound, and correct.

The “C” rating is, really, a thermal rating and relates to both current and internal resistance.

No battery, unless of excess voltage, will do damage to a load.

Conversely, excess load (stress), can certainly damage a battery, short term or long term, in the same way that high charge rates will reduce battery life.

So, a battery of correct voltage and high “C” rating will not “kill” but, if anything, in some installations, a high “C” battery might be regarded as “overkill”!

That “headroom” thing again which will only affect size, weight and cost considerations.

And on Mike Blandford’s point, all batteries deteriorate over time, even if well maintained. This is almost certainly down to a natural deterioration in their internal chemistry.

Edited By Keith Miles 2 on 14/01/2020 17:39:17

[Simon Chaddock]

Now if you can build a plane that only needs well under 1C from the battery to fly:

a) it will be able to fly for along time and

b) It will still be able to fly with significant battery degradation but just not for so long.

[Keith Miles 2]

Posted by Simon Chaddock on 14/01/2020 19:17:17:

Now if you can build a plane that only needs well under 1C from the battery to fly:

a) it will be able to fly for along time and

b) It will still be able to fly with significant battery degradation but just not for so long.

Which brings us nicely back to "fit for purpose" and "used appropriately"!