What is the ideal charging rate for that setup?

36v minimum, 50.4 max. Open for conments. I am thinking maybe 48-49v max charge, start at around 40. Know one doesn't want full charge or too low charge. I will talk with him more on this. My hearing is poor, too much construction noise. In person I do good. One can charge with high amps. It doesn't hurt them. That is the big adavtage for lithium. This will be a slow project. I have a total of 4 days off a month and that is subject to change depending on progress at work.Although, it is rumored I will be getting a upper supervisor position soon. Be lot easier  on me and feel more like doing this on my days off. Also be getting vaction time paid. We will see.

Edited October 7 by GlennWest

Ray was asking about current that you can charge at. Without bringing out the slide rule, 100 amps should be reasonable.

ETA: The vendor should have a spec sheet available for both the battery packs and the BMS he's supplying. Get all your charge parameters from there, don't depend on internet info for settings this important.

Edited October 7 by Darryl&Rita

You will need to research your charging rate. Tesla's will take 2 times the charging rate. i.e. a 75 kw battery can be charged at 150 kw, but they are water cooled to remove the heat produced by charging . BattleBorn's have no cooling and will accept a 1 C charge, 100 amps into a 100 amp hour battery.

Looks like your inverters will charge at 60 amps each. So charging a 400+ amp battery bank should not be a problem, but do double check with the seller.

I will. He was trying to tell me some on phone but my hearing no good on phone. He said he would supply all that with batteries. The reason I went with 21k is due to the nature of these batteries. Need to done in 14 module pairs.  18k doesn't work. He stated amps would be lower that I could draw from them. Needed to go 14k or 21k. Stated I could pull these down in the 20vish. Not that i want to though. I will get all this info correct when I get them and share with everyone. 

Charge at bulk and float at 57v.. Disable asbord.  Can charge at max 200amps. 40v-58v is operating range. His quotes. He is suppling a charge displaly unit.He also texted me that with the 2 magnum 4400 hybrid I would only be pulling 60 amps from each battery. #4 battery cable plenty. 

Edited October 7 by GlennWest

WOW Glenn, that's one nice system you're building. Unless I missed it, I'm curious, can you tell us the "ENERGY STORAGE Capacity" in Watt Hours or Amp Hours of those batteries ???

You mention having plenty of #2 Cable which it appears can "work" (even if I would use #1) and, of course, you could parallel a couple of them given proper connectors even if such isn't quite as professional looking. As you mentioned since it's a short run a few feet of No 1 isn't all that expensive. I like fine stranded Marine Grade cable for its improved flexibility and ability to withstand vibration. Regular old Welding Cable is fine stranded, flexible and has high quality insulation. Even if it takes more length I also like using a vibration/flex coil if possible.

Were having fun spending your money lol 

Keep us posted of your progress and choices, I'm enjoying this thread.

John T

  On 10/6/2019 at 11:02 PM, GlennWest said:

. Putting DC side online first. That is why I was asking about a DC/DC converter in my other post.

I have a Victron converter.  30a, 48v->12v.  Never any problems.

  On 10/7/2019 at 8:16 PM, oldjohnt said:

 Unless I missed it, I'm curious, can you tell us the "ENERGY STORAGE Capacity" in Watt Hours or Amp Hours of those batteries ???

As I read  it, 7k means 7,000 watts.  At 48v nominal that would be about 140ah each.

  On 10/7/2019 at 10:57 PM, hemsteadc said:

As I read  it, 7k means 7,000 watts.  At 48v nominal that would be about 140ah each.

Indeed "POWER" in Watts = Volt x Amps, so 7000 "Watts" at 48 Volts, (7000/48)  =  145.83   "AMPS"   

However, that's NOT "Amp Hours"  which is what I was asking Glenn about, I asked if he knew the batteries "Energy Storage" Capacity which is typically listed in "Watt HOURS" or "Amp HOURS", let me elaborate.

His post just stated 7K !!!! Is that POWER in "Watts" or "Watt Hours" of ENERGY ?? To me the term 7000 Battery "Watts" alone doesn't mean as much, its how many "Watt Hours" I want to know, and for sure 7000 "Watt Hours"  would be a good number if that's what was meant ????? Perhaps it is, but I have to ask....

Instantaneous POWER in Watts = Volts x Amps. ENERGY, which is what the electric utility charges you for, is Volts x Amps x Time. You are billed for how many KiloWattHours of Energy you used.  Often an RV or Golf Cart or similar Deep Cycle battery (an electrochemical energy storage device) is labeled in "Amp Hours" which is a measure of the available useful ENERGY it can store.

So Glenn, I was wondering if you know the "Energy Storage" capacity (in Amp HOURS or Watt HOURS) of those batteries ???

1) Maybe they aren't labeled as such and you don't know ??

2) Perhaps that  7K "Watts" you posted is really 7000 "Watt Hours" ??

 I'm just curious....

John T