Battery Sizing (load profile)
Battery Sizing (load profile)
(OP)
For battery sizing, can we convert a load (A) for 150ms to equivalent load for 1 sec, as a percentage value
e.g. 180 A for 150ms is equivalent to (150ms / 1000 ms) X 180 = 27 A for 1 sec (1000 ms)
This is required as the minimum time duration which we can use in battery sizing software is 1 sec.
e.g. 180 A for 150ms is equivalent to (150ms / 1000 ms) X 180 = 27 A for 1 sec (1000 ms)
This is required as the minimum time duration which we can use in battery sizing software is 1 sec.






RE: Battery Sizing (load profile)
RE: Battery Sizing (load profile)
First, you need to know your battery nameplate ratings. There is this thing called CCA--> cold cranking amps. It simply means the available current that can be drawn from a battery at 0 degrees F at a cell voltage of 1.2 volts (7.2 volts from a 12-volt battery) for 30 seconds. With the info on CCA, you can estimate if your battery can deliver the needed amps (even at freesing temps).
If you don't know your battery's CCA, you can estimate using CCA ~ 5 x RC,
Note: I found those information here.
RE: Battery Sizing (load profile)
RE: Battery Sizing (load profile)
I can't remember which supplier it is but there is a company that sells batteries and chargers that has a calculator that lets you put in a load profile, battery type, voltage constraints,number of cells,margin, and load characteristics (constant current or constant power) and then gives you what you need. At least what I remember for IEEE 485, it is a little more complicated than just adding up the amp-hours. Really hard loads at the start of the load profile cause the battery's amp-hour requirement to need to be larger than if the hard draws were nearer to the end of the profile. I think it was Hindlepower or someone that works close with them. Maybe, SBS?