rocketscience
1 µW
- Joined
- Aug 2, 2020
- Messages
- 1
Hi folks,
I'm considering buying a RSP-750-12 for charging a 4s 12.8 nominal 280ah lifepo4 battery pack. I'm looking at how to limit the current to 50a and whether I can get it's voltage up to about 13.8 or 13.9. I'm only looking to charge these to about 85% or 90% tops. I've done some searching around here and saw Doctorbass' posts, people were trying to limit the current using the trim pot which I think is only installed on the 1500 and 2000 versions. Doctorbass eliminated one of the sense resistors which cut the current in half.
After looking at the datasheet, it seems that there is a 14 pin CN50 connector in the rear that can be used to 'program' the current limit, voltage, remote sense, etc. It looks like you can use this connector to limit the current from 40%-110% of the factory setting of 62a, so theoretically 25a-68a. I think this, like other Mean Wells, starts to limit at 125% of the set current limit, so these numbers might be 25% higher.
The voltage can be controlled similarly with the CN50 connector from 40%-110%, and the unit also has a voltage adjustment pot in the back, The stated range in the datasheet is 10-13.5v, but it looks like you can get down to 4 or 5 volts and up to 14.6 or so by using the CN50?
https://www.meanwell.com/Upload/PDF/RSP-750/RSP-750-SPEC.PDF
My questions are:
-does anyone have any experience with 'programming' these?
-the datasheet specifies that an 'external voltage' needs to be used on the controlling pins, do you think an adjustable 2-5v dc/dc converter running off of the PSU's ouputs would work okay for this? Or could a resistor and jumper be used from the psu output to create the 2-5 and ground voltages?
-do you think it is likely I can get the voltage up to 13.8-14v? I've read that other RSP units have a wider voltage range than the datasheet (which specifies an upper limit of 13.5v). I'm hoping that the voltage adjustment screw and 'programming' are additive and will give me a wide range.
Thanks in advance for any help you can give! I've read a ton of posts on here, it's a great resource.
I'm considering buying a RSP-750-12 for charging a 4s 12.8 nominal 280ah lifepo4 battery pack. I'm looking at how to limit the current to 50a and whether I can get it's voltage up to about 13.8 or 13.9. I'm only looking to charge these to about 85% or 90% tops. I've done some searching around here and saw Doctorbass' posts, people were trying to limit the current using the trim pot which I think is only installed on the 1500 and 2000 versions. Doctorbass eliminated one of the sense resistors which cut the current in half.
After looking at the datasheet, it seems that there is a 14 pin CN50 connector in the rear that can be used to 'program' the current limit, voltage, remote sense, etc. It looks like you can use this connector to limit the current from 40%-110% of the factory setting of 62a, so theoretically 25a-68a. I think this, like other Mean Wells, starts to limit at 125% of the set current limit, so these numbers might be 25% higher.
The voltage can be controlled similarly with the CN50 connector from 40%-110%, and the unit also has a voltage adjustment pot in the back, The stated range in the datasheet is 10-13.5v, but it looks like you can get down to 4 or 5 volts and up to 14.6 or so by using the CN50?
https://www.meanwell.com/Upload/PDF/RSP-750/RSP-750-SPEC.PDF
My questions are:
-does anyone have any experience with 'programming' these?
-the datasheet specifies that an 'external voltage' needs to be used on the controlling pins, do you think an adjustable 2-5v dc/dc converter running off of the PSU's ouputs would work okay for this? Or could a resistor and jumper be used from the psu output to create the 2-5 and ground voltages?
-do you think it is likely I can get the voltage up to 13.8-14v? I've read that other RSP units have a wider voltage range than the datasheet (which specifies an upper limit of 13.5v). I'm hoping that the voltage adjustment screw and 'programming' are additive and will give me a wide range.
Thanks in advance for any help you can give! I've read a ton of posts on here, it's a great resource.
