charge profile, choosing charge controller

[Glenn West]

I have Leaf EV batteries. 21k total. Will be using Magnum 4448PAE inverters (2). Trying to decide on a charge controller. Looking at charge settings I am concerned about the Classis. I don't see a bulk setting. One of the major benefits of Lithium is the ability to throw a lot of power to them. Constant voltage/amps. I plan on 4k solar so a classic 150 is adequate. Magnum PT-100 I can set to bulk and float. I only see absorb on Classis. Every absorb I know of taper amps. Magnum is proud of there PT-100 so interested in the Classis of it can do what I need. I have bms with my batteiies.

[ClassicCrazy]

The Classic is always in the Bulk charge stage until it reaches the Absorb Setpoint and then it keeps the voltage steady until either the Absorb Time setpoint is reached or the Ending Amps ( via Whizbang ) is reached - which ever comes first. Then it goes to Float setpoint.

In Bulk it charges at all available amps though it may be limited if wanted .

Larry

[Glenn West]

So if I use a whizbang I can set ending amps at max voltage I want and it will bulk charge to that setting? Or do I even need the whizbag?

[ClassicCrazy]

Yes you need the Whizbang because it will be able to know exactly what is going into the battery and what is going into loads. You want to base your ending amps on what is going just into the battery and not what goes into loads. The maximum voltage will be your absorb setpoint but there is also another place in settings you can set a maximum voltage just as a backup .
There are some other discussions on the forums here about using Classic with Lithium batteries. Some of it depends on what the BMS or battery manufacturer is recommending.
Go to first Forum page and do a search there for lithium .

Larry

[Glenn West]

My charging profile is fairly straight fowrd. My operating range is 40v -58v. 58v max bulk chage. Float at 57v. I can charge at max of 200 amps. Never get that from solar.

[ClassicCrazy]

My charging profile is fairly straight fowrd. My operating range is 40v -58v. 58v max bulk chage. Float at 57v. I can charge at max of 200 amps. Never get that from solar.

You would need to know the Absorb Voltage setpoint, Ending Amps and or Absorb Time, as well as Float voltage.

Larry

[Glenn West]

But I don't need absorb. Sounds like I need to forget the Classic.

[ClassicCrazy]

Depending on how you set it up , it won't have much of an absorb. When I had my lithium batteries going it went right from Absorb to Float and could barely even notice it .

Larry

[Glenn West]

Looks like midnite would create a lithium profile so one would not have to set absorb. Like me trying to decide, I have never used one and really never set up one. So having a setting I can't use just seems wrong.

[ClassicCrazy]

Looks like midnite would create a lithium profile so one would not have to set absorb. Like me trying to decide, I have never used one and really never set up one. So having a setting I can't use just seems wrong.

It is probably best if you use a charge controller or the setpoints that your battery manufacturer recommends. That way you should have some confidence that the controller you choose and use will be the correct type for charging your batteries properly.

Larry

[Glenn West]

Person I got batterues from stated to bulk charge to 58v. Float at 57v. Disable equalize and absorb. What I read on Midnite Q&A is can't disable absorb. Can set for 3 minutes minuim. I am thinking 3 minutes is nothing really.

[Vic]

Person I got batterues from stated to bulk charge to 58v. Float at 57v. Disable equalize and absorb. What I read on Midnite Q&A is can't disable absorb. Can set for 3 minutes minuim. I am thinking 3 minutes is nothing really.

Glenn,   YES  !!   3 minutes is nothing.   From what Larry is saying,  his Abosrb is so short,  that it is difficult to note it on the display.

I do NOT believe that the PT-100 has any Bulk setting,   at least not with the DIP switches.

What would be set,  with a Bulk setting?

Bulk is called Constant Current (CC,  in this case) charging,  BUT,  with PV as a charge source,   it is very far from CC.  CC charging is from the perspective of Grid chargers,   where the charger has sufficient input power to charge at CC. Solar does not have that power available,  for much of the Bulk,  unless the battery is tiny or the PV array huge   ...   unless the charger waits and waits  for hours until there is sufficient PV power avail to actually do CC charging. You would need a much larger PV array to do this in a Solar Day.   And would gain nothing,  IMO.

Some Schneider  controllers that have a Boost charge voltage setting.  It is NOT a Bulk setting,  it just does a higher voltage stage than Absorb,   starting when the Absorb voltage has been reached (IIRC),   and after a time period,  it is reduced to the Absorb voltage setting.

The PT-100 manual has a graph of bulk and Absorb  where it has a dashed green horizontal line  at 100 A,   above the blue voltage line (that increases with time),   but that is just the MAX 100 Amp capability of the controller.  Because,  with PV as the power source,   nowhere that amount of current is avail from PVs at the start of a normal Bulk  (where there are no clouds of fog).

Just my take on things.    I know very little of Li batteries. FWIW,   Vic

[Glenn West]

PT-100 does do bulk and float. Use the remote for that. I am familiar with them. But I don't need that much controller though. That thing is a beast.

[Vic]

Ok Glenn,   Thanks,

BUT,   what is being Set with that Bulk setting ?  Vic

[Glenn West]

PT-100 does a cc/cv setting with remote which is constant current and volts. I may just use it anyway. I will already have the remote due to the inverters. Save me form having to buy a second remote.