Forcing bulk charge voltage

Started by mpomery, April 26, 2023, 09:04:45 AM

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mpomery

Hi, I am trying to configure a Kid for a lithium setup. Is it possible to set the bulk charge voltage to 14.4v?

ClassicCrazy

#1
You would have to set the Absorb voltage to 14.4v . It will charge with all available power up to current limit that you can set. When battery voltage gets up to 14.4v it will stay at that voltage until either the Absorb time setting is reached or Ending Amps if you have that set up. If you set up both Absorb time and Ending amps it will stay in Absorb until whichever comes first.

If you are asking if you can just set it to charge initially at 14.4v there is no way to do that I know of. It will always start charging at the present battery voltage.
here is more info on setting the Kid up for charging lithiums.
https://www.midniteftp.com/support/kb/faq.php?id=87

Larry
system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable

mpomery

Hi thanks for your reply, I've gone through this guis as well as a number of other resources but am not able to get the charger to behave as needed.

Essentially what is happening in the case my 100ah battery is near empty. I start up the Kid it bulk charges for a short period (<5mins) then goes to absorb mode.

Now absorb mode is where I'm having issue I believe.

The vendor (battleborn) recommends absorb for 20 mins. If I set this the kid only runs in absorb for 20 mins then goes to float. This essentially leaves the battery with very little charge (@250w input). Now I can set the absorb time to an absurdly high value but I am concerned this is not good for the batteries as it will essentially just keep pushing absorb for an extended period beyond the full point.

I'm guessing this is where end amps comes into play. If I set end amps to say 1a then I would imagine that once the battery if full it will stop drawing amps and go to float. Can you confirm this makes sense?

The config I will try is:

Abs V: 14.5
Abs time: 600
Float V: 13.6
Eq: None
Eq V: 14.5
End Amps: 1A
Rebulk V 13.4

Any thought are appreciated!





ClassicCrazy

Quote from: mpomery on April 27, 2023, 12:26:23 PMHi thanks for your reply, I've gone through this guis as well as a number of other resources but am not able to get the charger to behave as needed.

Essentially what is happening in the case my 100ah battery is near empty. I start up the Kid it bulk charges for a short period (<5mins) then goes to absorb mode.

Now absorb mode is where I'm having issue I believe.

The vendor (battleborn) recommends absorb for 20 mins. If I set this the kid only runs in absorb for 20 mins then goes to float. This essentially leaves the battery with very little charge (@250w input). Now I can set the absorb time to an absurdly high value but I am concerned this is not good for the batteries as it will essentially just keep pushing absorb for an extended period beyond the full point.

I'm guessing this is where end amps comes into play. If I set end amps to say 1a then I would imagine that once the battery if full it will stop drawing amps and go to float. Can you confirm this makes sense?

The config I will try is:

Abs V: 14.5
Abs time: 600
Float V: 13.6
Eq: None
Eq V: 14.5
End Amps: 1A
Rebulk V 13.4

Any thought are appreciated!


I think Ryan mentioned in a previous post that the Kid had an issue with charging lithium batteries and they were working on a firmware fix for it. But not sure if an update ever was released.
I don't have time to find that previous post now but you could contact Midnite support or email Ryan and ask him about it.
I wouldn't put the extra long absorb time on there. Do you have a whizbang on your Kid to be able to use ending amps - 1 amp sounds too low for ending amps.
Larry
system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable

ClassicCrazy

#4
see this post
I remember now , I was charging 12v lithium battery for a friend and I was using Kid and it did what you are talking about , went to absorb too fast.
https://midniteftp.com/forum/index.php?topic=5877.msg54252#msg54252

Larry
system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable