Understanding battery pack selection in relation to motor and ESC??

[mikeoui]

After 5 long years of dependable use, my lipos finally swelled up. Im looking to replace these, but its been so long since I had to consider packs.

I have a Miss Geico 29 BL v2 and was using 2 x 7.4v 5300 mAh 40c 2S cells. Its got the stock 1600kv (I think) motor, but I got the boat into the cabbage and cooked the stock 60A ESC. Proboat replaced it under warranty with the 80A ESC. Someone mentioned to me that I could run. Higher S count, but I dont remember how I would set that up. I found this site and I understand how to calculate the numbers, but I dont fully comprehend what my limitations are? With an 80A ESC, I assume I can handle 80A max? Or are there amperage limitations on the motor?

https://www.radiocontrolinfo.com/inf...on-calculator/

Forgive the lack of punctuation... looks like vbulletin still doesn?t like mobile lol!

[fweasel]

If you're going to continue to run on 4S (two 2S packs in series), and 80A ESC should be sufficient with something close to the stock prop size and a setup that isn't plowing the hull through the water. Shoot for Lipo's rated at 50C or better, but understand that number is mostly made up marketing. It's safe to say a 75C packs is better than a 50C pack from the same manufacturer, but between brands, its a crap shoot.

If you want to run on 6S, which many do on the 29" Proboat cat hulls, that's two 3S packs in series. Same lipo concepts apply, look for 50C or better. However, you're 80A ESC won't be nearly enough. 120A at the absolute minumum (came stock on the V3 version of that boat) but 150-180A gives more safety headroom. You can go inexpensive like a FLycolor 150A or something like the Seaking 180A for a little more.

[mikeoui]

Thanks! That?s pretty much inline with what I was trying to figure out. I forgot, I do have a GrimRacer prop on the boat. I can?t recall the specifics, but I do remember researching it and it was a modest prop for a stock motor. Since I?m not looking to pump a ton of money into getting it going again I?ll look for a high C rating but stick with 4S

[mikeoui]

So I ordered a pair of 7.4v 5200 mAh 2S 80C batteries. I ran there?s specs through the calculator on that page and I got a Maximum Continuous of Discharge rate 700 Amps and a Maximum Recommended Continuous Discharge rate 420 Amps. Given these numbers, shouldn?t this way exceed the 80A my ESC is capable of handling? Or am I misinterpreting that figure?

[NativePaul]

No worries, it is good to have LiPos that are capable of more than the system will pull, to avoid stressing the cells too hard and getting into a thermal runaway situation.

The quoted 80C is BS anyway, the best cells available at the moment are capable of approx 55C. Anything past that is the seller pulling numbers out of their butts for marketing purposes.