What does this max wattage mean on these UPP batteries?
- Thread starter RoninX
- Start date
slaphappygamer
10 kW
The watts are listed to let you know what motor they should be paired with, per the dealer. For example, the 52v 20ah battery is best paired with a 1500w motor. Ultimately, it’s up to the user to set the controller as needed. Depends on what the BMS is rated for.
Voltron
1 MW
Those batteries are just different voltages and capacities, which makes them hold different watt hours.
But that is not the same as how many watts you can pull out of them safely.
Generally higher amp hour batteries can sustain more watt output since there's more cells paralleled up in each group.
The only difference you should notice between them is the range you'll get, unless you put a small battery on a system with lots of amp draw, where the BMS or the cells themselves start limiting the power.
But that is not the same as how many watts you can pull out of them safely.
Generally higher amp hour batteries can sustain more watt output since there's more cells paralleled up in each group.
The only difference you should notice between them is the range you'll get, unless you put a small battery on a system with lots of amp draw, where the BMS or the cells themselves start limiting the power.
I got it, thanks.
I assume then that mention of top watts is for hub motors. I was planning on getting the 0-1500w for a 1000w bbshd, and in all my research, I never read anything on changing the controller settings to accept some battery that the seller calls 0-1500w.
The watt limitation is for any load, any type of motor, or even a non-motor load.
If you get a battery that is more capable than the system needs, that's a good thing and doesn't need anything changed to deal with it.
Generally you don't change settings in the system to make it accept a specific wattage-capability battery (exception noted later); you get a battery that can handle the worst case wattage of the system it's got to run. Specifically it has to handle the *current*, or Amps (A, not Ah or Amp-Hour) that the controller will draw. So if a system has a 20A controller, then the battery must be able to handle 20A. If it has no specific A (not Ah) rating, then you can only guess based on the wattage it is advertised as, divided by the volts it is advertised as, for what the A limit might be. Calculations are guesses because you don't know how they arrived at the wattage rating, and it is voltage dependent, so any reverse calculation you make may be using a different voltage, which gives you a different current limit that may not represent reality.
The exception to changing a system setting to work with a specific battery is that if you have a battery that cannot handle the current a system requires, you can change the system current limit lower to match what the battery can actually handle.
If a battery is properly designed and built, with the correct parts and protections in place, the BMS will simply turn the output off if the current limit of the battery is exceeded. But many batteries are not properly designed or built, and you can't know if yours is until something goes wrong because of it (or you take it apart and verify everything and rebuild it as needed).
In these cases, it could have the FETs in the BMS fail stuck on, so it cannot ever shut the output off no matter what goes wrong inside the battery (leading to cell damage and sometimes fires). Or the BMS may not even check current, so it never even attempts to protect against such a situation. Or other possible scenarios that lead to problems later, if no immediate ones occur.
There's enough info in the listing to guesstimate what's going on. For the pack you have highlighted, 52V 20Ah LG4800 cells, is enough to identify what cells are likely used, the LG INR21700, which is good for 4.8Ah and 9.3A continuous. The pack is likely 14S4P to get to 20Ah. With 4P, the rated continuous current would be 37.2A. At 52V, that's 1934watts continuous or good enough for a 1500W motor.
Thanks, and I do get the general amps / watts stuff on the BATs like from watching various videos, such asThe watt limitation is for any load, any type of motor, or even a non-motor load.
If you get a battery that is more capable than the system needs, that's a good thing and doesn't need anything changed to deal with it.
Generally you don't change settings in the system to make it accept a specific wattage-capability battery (exception noted later); you get a battery that can handle the worst case wattage of the system it's got to run. Specifically it has to handle the *current*, or Amps (A, not Ah or Amp-Hour) that the controller will draw. So if a system has a 20A controller, then the battery must be able to handle 20A. If it has no specific A (not Ah) rating, then you can only guess based on the wattage it is advertised as, divided by the volts it is advertised as, for what the A limit might be. Calculations are guesses because you don't know how they arrived at the wattage rating, and it is voltage dependent, so any reverse calculation you make may be using a different voltage, which gives you a different current limit that may not represent reality.
The exception to changing a system setting to work with a specific battery is that if you have a battery that cannot handle the current a system requires, you can change the system current limit lower to match what the battery can actually handle.
If a battery is properly designed and built, with the correct parts and protections in place, the BMS will simply turn the output off if the current limit of the battery is exceeded. But many batteries are not properly designed or built, and you can't know if yours is until something goes wrong because of it (or you take it apart and verify everything and rebuild it as needed).
In these cases, it could have the FETs in the BMS fail stuck on, so it cannot ever shut the output off no matter what goes wrong inside the battery (leading to cell damage and sometimes fires). Or the BMS may not even check current, so it never even attempts to protect against such a situation. Or other possible scenarios that lead to problems later, if no immediate ones occur.
Yea, if you know all about the battery stuff in depth. I don't. I was thrown off by the way it was said. places like EM3ev and PswPower don't say 0- this or 0-that crap that just confuses you. And I'm sure all those BATs can be used on a 750W BBS02. Unless the maker is doing something radical to the batteries, hence my question about the wording.
Also, I believe this is wrong. You can use PhaseRunner or an ACI BAC controller with a normal battery that cant handle 60 or 90 amps output.The watt limitation is for any load, any type of motor, or even a non-motor load.
If you get a battery that is more capable than the system needs, that's a good thing and doesn't need anything changed to deal with it.
Generally you don't change settings in the system to make it accept a specific wattage-capability battery (exception noted later); you get a battery that can handle the worst case wattage of the system it's got to run. Specifically it has to handle the *current*, or Amps (A, not Ah or Amp-Hour) that the controller will draw. So if a system has a 20A controller, then the battery must be able to handle 20A. If it has no specific A (not Ah) rating, then you can only guess based on the wattage it is advertised as, divided by the volts it is advertised as, for what the A limit might be. Calculations are guesses because you don't know how they arrived at the wattage rating, and it is voltage dependent, so any reverse calculation you make may be using a different voltage, which gives you a different current limit that may not represent reality.
The exception to changing a system setting to work with a specific battery is that if you have a battery that cannot handle the current a system requires, you can change the system current limit lower to match what the battery can actually handle.
If a battery is properly designed and built, with the correct parts and protections in place, the BMS will simply turn the output off if the current limit of the battery is exceeded. But many batteries are not properly designed or built, and you can't know if yours is until something goes wrong because of it (or you take it apart and verify everything and rebuild it as needed).
In these cases, it could have the FETs in the BMS fail stuck on, so it cannot ever shut the output off no matter what goes wrong inside the battery (leading to cell damage and sometimes fires). Or the BMS may not even check current, so it never even attempts to protect against such a situation. Or other possible scenarios that lead to problems later, if no immediate ones occur.
Only by (as I noted) changing the settings in the controller to limit the current to what the battery can handle. That is true of any controller (or any other load placed on a battery that's less capable than the load may demand) .
If you use a battery that can't handle the current on a controller that's actually demanding that much current, you either have shutdowns from the battery (total power cutoff) if the battery is properly designed and built, or damage to the battery if it is not (and excessive voltage sag that can cause various error conditions in the controller, or simply keep it from having enough watts (v x a) to do the work required.
It's different from the typical way it's stated; I expect they did that because people often ask how they can use a 1500w battery with a 250w motor, because it is common for people to think the battery will "overpower" the motor, not understanding that the motor will only draw as much as the load demands, and if it is limited to a certain amount of power (or current) then it won't draw more than that under any load, even if the battery is capable of more. (we get this question frequently)
I thought they were 18650's which are more stable. hard pass on that set.
just searched google and an LG4800 battery doesnt even exist. so how did you come to that conclusion, battery professor?
slaphappygamer
10 kW
LG brand, 4800mah capacity.
Here is the datasheet
Here is the datasheet
Just guesses based on the info in the listing and process of elimination.
I plan on building my next pack with 21700 cells. Sort of leaning toward the Molicel P42A, but still deciding. The 45A discharge rating is attractive, so a 5P 21Ah pack would provide 200A with some cushion.
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