Not directly related, but this stems from the IMR 16500 that HKJ reviewed.
I struggled to understand what used this size as a 1 x 16500. I had proposed that 2x 16500 = 3 x CR123a. But HKJ seem against running these in series without protection.
For those threads:
And here is a quote from HKJ:
[QUOTE=HKJ;4588196]No LiIon chemistry is completely safe, they all needs protection. Generally IMR will be safer, but a reverse charge is always problematic and for a protected cell this cannot happen.
[/QUOTE]
I think based on the conversation that HKJ was saying (although I don’t have direct confirmation):
For series use:
-protected cells = yes
-non protected cells = no
However, as IMR’s generally (or almost exclusively) can’t be found protected. That would also mean:
For series use:
-IMR = no.
Now I may have gotten this wrong, if so I apologise to HKJ, but I would truly love to learn from all of this. And for the record I have huge respect for HKJ and I’m not questioning what they say, just seeking a “why” to it.
Part of my reasoning is, I was just thinking about RC batteries. As I understand it a LiPo uses pretty much the same chemical make-up as ICR’s do.
But RC LiPo’s are not protected and almost all of them are multi-cells in series.
Ok, most have a balance plug for charging. But during discharge there is nothing, just a single connector, which brings us back to the issue of reverse charging.
How come this isn’t really a problem in the RC world? 3, 4, 5 and even 6S is pretty common. And all with high discharge use. Many speed controllers will have low voltage warning, but that will be the entire packs voltage, not each individual cell.
If it isn’t a problem, fundamentally is there then any difference to an individual taking non protected ICR or IMR’s and “balance charging them”, i.e. making sure they are pretty similar voltage when charged and using matched pairs.
And then run them in series and just be mindful not to run them too low?
I suppose all in all the questions I’m asking is:
-Is the risk really any different between RC multi cell and flashlight multi cell? (I suppose physical proximity to the battery might be, as you hold a light, but not an RC plane/car).
-Is it really risky and inadvisable to run IMR’s in series?