Tyro65
100 mW
How can a 60V 20Ah battery pack generate 420Wh?
Teach me, please.
Teach me, please.
Calculating Watts
- Thread starter Tyro65
- Start date
Do you want to know watts (title of thread), or watt-hours (post)? They're completely different things, despite the similarity of name.
For the latter you just multiply the *average* voltage of the battery by the capacity in Ah. I don't know if your listed voltage is full-charge or average.
For the former you need to know the current-delivery (A) capability of the battery, which isn't stated in your post.
What specifically are you trying to figure out? (beyond the actual number, or how to find it).
For the latter you just multiply the *average* voltage of the battery by the capacity in Ah. I don't know if your listed voltage is full-charge or average.
For the former you need to know the current-delivery (A) capability of the battery, which isn't stated in your post.
What specifically are you trying to figure out? (beyond the actual number, or how to find it).
offGridDownUnder
10 kW
You didn't tell us who or what says that it does. For example, is this a marketing claim in an ad? I have seen ads for batteries with physics-defying claims - so what is this from?
Tyro65
100 mW
I"m looking at this. "If it's too good to be true . . ."
I'm just trying to learn all I can about it. In the description, It has this:
Energy
- Nominal Voltage: 60V
- Output Voltage Range: 44v - 67.2v
- Nominal Capacity: 20Ah
- Nominal Power : 420Wh
floydr
100 W
if the seller can't even do simple math what are the chances the battery is any good?
59.2V x 20Ah = 1184Wh
the specs are for a 10Ah battery.
later floyd
59.2V x 20Ah = 1184Wh
later floyd
Last edited:
Good instincts. It’s junk.
docw009
10 MW
Ready for some Science and Math?
First 1000 mah is 1 AH. You divide the mah number by 1000 to get AH,
420WH for a 60V battery means the battery is rated 7AH on paper. Divide the 420WH by 60V and that result is the AH for the battery. In this case, it's 7AH, Just remember that Watt-Hour = Voltage times AH,
Now here's how to understand AH, This is a 32 cell battery arranged as 16x2 cell combo, otherwise called a 16S-2P. You divide the AH number by the P value and that's the individual AH rating of each cell. Here, that's 7 divided by 2, and 3.5AH is the cell rating, 18650 cells for ebikes usually range from 2.4 to 3.5 AH.
These bozo battery sellers figure no one understands the numbers, so they lie like mad and say 20000 mah.
If you read this far and buy that battery, it's going to run like a 60V 5Ah, if you're lucky,
First 1000 mah is 1 AH. You divide the mah number by 1000 to get AH,
420WH for a 60V battery means the battery is rated 7AH on paper. Divide the 420WH by 60V and that result is the AH for the battery. In this case, it's 7AH, Just remember that Watt-Hour = Voltage times AH,
Now here's how to understand AH, This is a 32 cell battery arranged as 16x2 cell combo, otherwise called a 16S-2P. You divide the AH number by the P value and that's the individual AH rating of each cell. Here, that's 7 divided by 2, and 3.5AH is the cell rating, 18650 cells for ebikes usually range from 2.4 to 3.5 AH.
These bozo battery sellers figure no one understands the numbers, so they lie like mad and say 20000 mah.
If you read this far and buy that battery, it's going to run like a 60V 5Ah, if you're lucky,
If it's a cheap battery from a seller you've never heard of, it's probably not even worth whatever minimal price they're charging.
It's more likely, based on the little info that's on that page, that it's just yet another blue fire hazard.
There's a lot of BFH's out there...to avoid them don't look for cheap batteries. Look for a seller / manufacturer that you *trust*, and buy from them.
It doesn't actually list a power rating, despite the term they used, because they used Wh as the units. Wh is a capacity, not a power rating. It would have to be in W to be a power rating.
If it's a power rating, it means it is nominally capable of outputting 420W, but you don't know what it's max or continuous ratings are, so you can't really know if it can work on any particular system.
If it's a capacity rating, then it doesn't match the other provided numbers that must be used to calculate it.
Because they can't get that right, you can't know that *any* of their info is correct, because you don't know which number they got wrong--the volts, the Ah capacity, or the Wh capacity.
Because of that, you can't trust anything from any of their sales or pages.
It's unlikely that they have any idea what they are selling, they probably just buy whatever they can get in lots, and post it up. The info on that page may even be from a totally different product that they used to sell.... (sellers on amazon do that all the time, and you will often see reviews for items that are not sold on that page because it's what the page *used* to be for.
offGridDownUnder
10 kW
Responding to the OP, rather than to amberwolf...
Have a look at this thread, and especially the video posted at the beginning:
Grin’s perspective of Ebike fires
Substantial experience over time shows that the single best indicator of whether a cell will ignite is the quality of the cell manufacturer. You can't tell by any measurement you make of the cell, except for measuring if the cell was manufactured by one of the established, responsible manufacturers.
Sony, Samsung, LG, Panasonic. Perhaps there are a few others. They know how to make Li-ion cells and they are responsible and you pay for it - but keep in mind that with Li-ion cells you are paying with your life if you buy poor quality. Li-ion cells explode, like literally explode - and release toxic gasses, so you won't wake up to throw them outside.
- Buy cells made by one of the reputable foundries.
- Do not permit them to discharge beyond their limit (which varies slightly by the actual chemistry - but about 20% of total capacity).
- Do not overcharge them (and if you keep them usually below 80% you'll also triple the life of the cell which easily over balances the 'extra cost' up front).
- Do not overheat them.
- Do not smack them around.
