ProBoat UL19_76mph!

[Xrayted]

Does your charger have a method for testing the cells IR? It won't be accurate using a charger to do so, but the values are repeatable from a baseline, so it would be interesting to see what the IR is on your MA packs at 70F or so room temp after they have been resting in the room for a few hours to adapt to the temp. Then it becomes easy to see those cells and any subsequent changes in the IR under the identical testing scenario as the cells starts to get some wear on them.

My newest 5200mAh SMC packs IR per cell range was 1.2-1.4 milliohms which is what I expect from a really good brand new 5K capacity pack. I have packs from them from last year that are now drifting up into the 1.5 per cell range, but that's great considering the abuse I have put them though, as in the end how long the pack will last matters most. Cheap packs aren't so cheap if you need to replace them 2-3X as often, but that isnt the case with the SMCs. They are cheap and last!

[sammyha]

I only look at those numbers while charging. They're 0.9-1.2 on these packs

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[Bande1]

Does your charger have a method for testing the cells IR? It won't be accurate using a charger to do so, but the values are repeatable from a baseline, so it would be interesting to see what the IR is on your MA packs at 70F or so room temp after they have been resting in the room for a few hours to adapt to the temp. Then it becomes easy to see those cells and any subsequent changes in the IR under the identical testing scenario as the cells starts to get some wear on them.

My newest 5200mAh SMC packs IR per cell range was 1.2-1.4 milliohms which is what I expect from a really good brand new 5K capacity pack. I have packs from them from last year that are now drifting up into the 1.5 per cell range, but that's great considering the abuse I have put them though, as in the end how long the pack will last matters most. Cheap packs aren't so cheap if you need to replace them 2-3X as often, but that isnt the case with the SMCs. They are cheap and last!

I got some Nihewo 7500 100c packs that are 1.0-1.2 when charged. They drop to 3.36v under load within seconds. load being about 175a.

[Xrayted]

Those are good numbers sammyha, at least out of the gate on a new pack, so it will be interesting to see how long they hold up before getting tired. Its always tricky testing while charging because IR is very sensitive to temp, and the charging cycle itself can cause enough heat in the chemistry to make the IR lower than it really is. I try and test right after connecting the pack to charge and within a few seconds of the charge start to try and have some consistency. You cant test at all if the pack has been run in any way without several hours of waiting for the pack temp to normalize back to room temp ambient

Anyway, good luck and hope they last a few seasons at least for you!

[Xrayted]

I got some Nihewo 7500 100c packs that are 1.0-1.2 when charged. They drop to 3.36v under load within seconds. load being about 175a.

Yeah, because 175A continuous is a lot of current, even for a good pack! The top five packs on their testing at 175A dropped down to 3.7V per cell within 10 to 36 seconds. It doesnt sound like much, but 175A for 36 seconds straight is waaaay more than the 14G wiring on most of out packs can handle, hence why our boats all get so hot. The equipment we are using is running right on the ragged edge of what we are asking of it, so I'm surprised things last even a few runs in some cases.

[sammyha]

They are usually sitting in my basement model room overnight. I charge in the morning before I head out. So they're normalized at usually 65 degrees.

I'm getting a pair of 4s SMC lipos for my RSX 380 for sure...

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