AI Specs are freaking me out Molicel P50B

[TRS300]

So I just bought a bunch of the P50b 21700 cells from 18650BAYTERYSTORE and when doing a search on both ChatGBT and Grok 3 they both report much lower continuous discharge rates then what the website specs stated. The website said 60A continuous, I was going to design for 50A max per series. And both AI responses say 30A or less continuous! What the heck? Can anyone help me know if I'm OK or did I just spend alot of money under false advertising? The attached Pic is from the website where I bought the cells.

 

[pwd]

First lesson is don't trust the AI figures. Verify in the cells datasheet and independent cell tests (YouTube etc..).

 

[BatteryMooch]

So I just bought a bunch of the P50b 21700 cells from 18650BAYTERYSTORE and when doing a search on both ChatGBT and Grok 3 they both report much lower continuous discharge rates then what the website specs stated. The website said 60A continuous, I was going to design for 50A max per series. And both AI responses say 30A or less continuous! What the heck? Can anyone help me know if I'm OK or did I just spend alot of money under false advertising? The attached Pic is from the website where I bought the cells.

The P50B does have a 60A continuous current rating, for a single cell in open air, in the datasheet. But it’s a “temperature limited” rating. This means you can run the cell at up to 60A continuous but you must stop before the cell reaches 80°C.

The “true” continuous current rating, where you go down to 2.5V in a single continuous discharge, is lower…35A was my estimate.

Which rating you use depends on how you will be running them. You say 50A max, but how long you run them at that level really matters. Especially in a battery pack where the cells can heat up a lot, forcing you to “derate” them by lowering their current rating. You’ll need to build a test pack and see what temps your cells reach for your discharge profile(s).

50A is huge for a single cell though, even for a cell like the EVE 50PL, and will get you a lot of voltage sag and accelerated aging.

 

[BatteryMooch]

First lesson is don't trust the AI figures. Verify in the cells datasheet and independent cell tests (YouTube etc..).

I agree. Using any of the AI resources will very often get you junk info. Especially with topics like this.

 

[TRS300]

I agree. Using any of the AI resources will very often get you junk info. Especially with topics like thisl

First lesson is don't trust the AI figures. Verify in the cells datasheet and independent cell tests (YouTube etc..).

I did find a spec sheet that shows the same specs as the battery store website says... But frankly Ive read that all the specs on these cells are possibly false. So I was hoping to get some input from folks here that know more than me on if the P50b could be expected to be able to supply 50A continuous without excessive stress on the cell. I don't plan to draw that current continuously. I'm trying to build in overhead for peak demand periods without causing damage or a hazardous condition from pushing a cell beyond what it's designed to handle.
Yes I do research on the web and on YouTube, but I also joined this forum because of all the knowledgeable people here...

 

[BatteryMooch]

I did find a spec sheet that shows the same specs as the battery store website says... But frankly Ive read that all the specs on these cells are possibly false. So I was hoping to get some input from folks here that know more than me on if the P50b could be expected to be able to supply 50A continuous without excessive stress on the cell. I don't plan to draw that current continuously. I'm trying to build in overhead for peak demand periods without causing damage or a hazardous condition from pushing a cell beyond what it's designed to handle.
Yes I do research on the web and on YouTube, but I also joined this forum because of all the knowledgeable people here...

Where did you read that all the specs on P50B’s are fake? They can easily be downloaded from Molicel’s web site and confirmed.

You ask if P50B’s can supply 50A continuous…but for how long?
Then I get confused because you say you won‘t be running them continuously. For how long and how long a rest before doing that again?

 

[TRS300]

Where did you read that all the specs on P50B’s are fake? They can easily be downloaded from Molicel’s web site and confirmed.

You ask if P50B’s can supply 50A continuous…but for how long?
Then I get confused because you say you won‘t be running them continuously. For how long and how long a rest before doing that again?

I've got a fair amount of basic electrical knowledge but don't know much about battery chemistry. So yes, usually spec sheets are where I draw real information from. I think maybe I took comments regarding false claims regarding pre-made batteries and thought that even spec sheets might be false but I think I misunderstood.

My comment about not planning to draw high current continously is because it will be used on a vehicle. And like any normal use vehicle you don't drive around demanding full power continously all the time. But you also want to be sure that if a situation came up where you did need to draw near design maximum for an abnormal length of time (a long hill) that the pack would not be damaged.

So based on the spec sheet I think these cells should be OK. Now I can try and learn everything else I need to know to build a good battery... Haha.

 

[gromike]

Building batteries is such a relaxing, and sociable hobby!
If you frock up you can burn off precious body parts, and/or burn your house down.
Go ahead, sit around at the tavern and tell your friends about building a battery. Go into detail they all look at you funny and slowly edge away.
That being said, from my experience, casing and mounting a battery is the most time consuming part of the process. My builds have been standard ebike type batteries, not all that complicated. Those who build those big high power banks, well that is a whole other world.

 

[TRS300]

Building batteries is such a relaxing, and sociable hobby!
If you frock up you can burn off precious body parts, and/or burn your house down.
Go ahead, sit around at the tavern and tell your friends about building a battery. Go into detail they all look at you funny and slowly edge away.
That being said, from my experience, casing and mounting a battery is the most time consuming part of the process. My builds have been standard ebike type batteries, not all that complicated. Those who build those big high power banks, well that is a whole other world.

Haha. Funny but true. I worked my whole career in pretty dangerous manufacturing environments. Lockout Tagout and removing all hazardous potential was absolutely mandatory. So to be working with live cells is a bit unnerving to me. I've even thought about what I can do to reduce risk. It really is quite unsafe. You must be from the northeast. That's where those "Taverns" are.

 

[amberwolf]

As BatteryMooch points out, the spec sheets are not for what a cell can do in a pack.

What it can do there depends on the pack design...but it wouldn't be unfair to cut any cell's rating in half to be sure the pack can always do what you need it to, regardless of state of charge, even as it ages (because capabilty drops in both situations, and this just grows worse with time and use).