8 large Crown battery 6v 235 amp for 5hr for 48v system

Fuseboxer

I am a novice and I am new to your group. I have had very good luck with a solar system in a hunting cabin up North 150 miles in the Bush.  I decided to try again at home mostly for emergencies.  I combined a small generac, company generac installed and my 6000 watt Sigineer split phase inverter/charger 240v with triple output for 20 seconds.  100% Ames but cheaper cost.  I believe this is a good match for a small sub panel /generac generator.
  My question is how long should my large Crown batteries,  purchased new, run my inverter.  8-235amp for 5 hr 6 volt= 48 volt .  My inverter shows 3% and most of the time 5% use.  I do not use powersaver it kills my alarm, camera and wifi.  On low or no use. without powersaver it draws 1.7 amps.  Too many times I go to bed and sleep and the Generac generator kicks on at 4AM.  Yes the inverter is set to "save batteries "  by auto shut down at 44 volts.  Full  bat charge at 5PM. and shut off 9 hr later.  I have a 2kw pv with plenty of power in the day time  but die 10 hrs later with what I believe is near idle power use.  Only 240v is my well pump for showers.  Sump pump almost never is on.  The blower motor is on with the air conditioning but not the compressor.  Compressor is street power.  How long should I be able to run on my 8 large Crown batteries?????   Thanks I am a green horn that got lucky in the past with a cabin and very little cost.  We use it for a few days to a week in the summer frequently and in the fall for deer hunting.  NO BEAR HUNTING but we have a lot bruens around.

Fuseboxer

9PM now dark for 2 hrs my batteries show 50 volt yet battery meter shows 3/4.  Many times when I shut off at 44 volt the next morning after sitting a few hours it claims 50 volt.  I for got to mention Sigineer inverter made 100% Aims factory.

mike95490

When you start the generator up, does the battery reach full charge in a couple hours, or does it need 6 hours ?

Fuseboxer

Can not use volts to determine bat charge condition.  50v should be full bat yet the bat meter visual display can show 1/4 down.  Thanks for your idea of  time to charge.  When it shuts off at times at 3AM  when I look at 7AM, no sun yet, the meter can say 49 or 50v.  

Am I wrong in believing 5% use on the front of the inverter display is very low amp draw that should have the bat last for many days without sun?  Inverter uses at idle is 1.7 amp.  5% of 6000watt = 300watt/ 240 = 1.25 amp so it default min is 1.7 amp draw.  

What is the math on my bat bank for it to drop from full approx. 60v to 44v and inverter shuts off.  How many amps used from full to shutdown.  I know my week link is the bat but will wait a few years for technology to go up and price to go down.  

I like my .2 of a second response time for inverter to kick in when street power shuts down.  I like my generator auto backing up my inverter but it takes about 5 sec to start.  I like my street power automatically shutting off inverter and or generator.

Dave Angelini

How long is the time at 60V? Should be 3 or more hours. Crown are flooded batteries? If so you need a hydrometer. Also read the crown product manual and do what they say. You probably should buy a KWH meter.

 https://www.amazon.com/Poniie-PN1500-Electricity-Electrical-Consumption/dp/B07VPTN8FZ/ref=sr_1_5?dchild=1&keywords=kwh&qid=1600270088&sr=8-5

You definitely can't trust the inverter display unless you calibrate it with a different source.

Photowhit

Fuseboxer said;
...50v should be full bat yet the bat meter visual display can show 1/4 down. 

So this premise is wrong, While battery voltage is always a poor way to measure battery capacity, and flooded lead acid batteries will vary slightly. Most would consider 50 volts to be around 80% state of charge, perhaps a little more. Here's an example;


If it's a simple 4 light, system read what it means for each light to be lit. 3 lights may indicate 75-90%...

Get a hydrometer, use a hydrometer to determine the state of charge (SOC)

mike95490

I'm thinking the batteries are sulfated if they recharge quickly, and then run down quickly

Fuseboxer

I appreciate the ideas you all have good  points.  The Crown bats are flooded.  Three lights on a four light system came as an auxiliary control with the inverter I would have to find the book to see if  it states.  I had no idea that I was discharging my bats to 5%  when going to 44v.  My info with the inverter claims 44v shut off is safe for my lead acid bats to increase long life.  

Dave Angelini

Mike is right but the same thing will happen if the absorb time is too short. There are no easy answers with so much basic info missing here Mr Fuse boxer!

Fuseboxer

Photowhit

Fuseboxer said:

I appreciate the ideas you all have good  points.  The Crown bats are flooded.  Three lights on a four light system came as an auxiliary control with the inverter I would have to find the book to see if  it states.  I had no idea that I was discharging my bats to 5%  when going to 44v.  My info with the inverter claims 44v shut off is safe for my lead acid bats to increase long life.  

Inverter shut off's are to protect the INVERTER! Not the battery. 

With a large load voltage can fluctuate a large amount, this particularly noticeable as the battery's capacity is reduced as the load represents a large % of the remaining capacity.

mike95490

44V is a destroyed 48V bank.  
 The 44v is to manage short surges and voltage drop in the cables. much more than 20 or 30 seconds, the inverter shuts down to protect itself, not the batteries.   The inverter's job is to provide as much AC power for as long as it safely can, it cares nothing for your batteries.

mcgivor

The inverter itself consumes ~2kwh per day, or 35% of the usable capacity of the battery, which is 50% of nominal capacity. You may want to consider a smaller inverter with lower tare consumption for overnight as your current regime of discharge is going to end in dissapointment, as pointed out above.

What puzzles me is there is  reference to having street power which I would assume is grid, then reference to generator charging, why on earth would one utilize anything other than grid if available? Both batteries and generator are very inefficient means of providing energy in most cases, when compared to grid costs, since the Sigineer appears to be an inverter charger why use a generator for anything other than backup to the batteries during an extended power outage.

Just reading between the lines trying to figure out what it is you're attempting to achieve and having a hard time doing so. Should this be an experiment to understand the limitations of a backup system, I would highly suggest utilizing a battery monitoring system to start the generator  at a higher voltage than the inverters self presivation, batteries dead value.

Fuseboxer

I charged the bats with street power and some solar to make sure I have a full charge.  I waited 10 min to let the bat normal w/o ch and I made measurements.  Volt meter shows 52.1 volts for the set of 8 bat.  3 bat are 6.8v, 4 bat are 6.7v, and one bat is 6.6v.  
Bat #1= 1.275, 1.275,1.275;  Bat #2= 1.275,1.275,1.275; Bat#3= 1.25,1.25,1.25;  Bat#4=1.25, 1.25,1.25; Bat#5= 1.275,1.25,1.25;  Bat #6= 1.25, 1.27, 1.25;  Bat #7= 1.25,1.25,1.25;  Bat#8= 1.25,1.25,1.25.  

My inverter has a setting on its charger with high power for de-sulferization lead acid batteries.  It comes with warnings and no instructions.  Should I disconnect the PV charge controller and turn on the high power for 5 min then 5 min cool then 5 min high de- sulferization???

I look foward to reading past group info and my doing less talking and more learning

littleharbor2

Fuseboxer said:

 I waited 10 min to let the bat normal w/o ch and I made measurements.  

You need to wait a lot longer than 10 minutes to allow the surface charge voltage to equalize. more like 2-3 hours minimum.

Fuseboxer

What about the specific gravity does that also need to be redone?  What about my high power bat rejuviner.  How do I do it and do I need it?

Fuseboxer

You are rite on.  Bat 1 is now 6.51 was 6.8;  bat 2 is 6.48 was 6.6;  bat 3 is6.51 was 6.7;  bat 4 is 6.52 was 6.7;  bat5 is 6.31 was 6.7;  bat 6 is 6.51 was 6.7;  bat7 is 6.51 was 6.8;  bat8 is 6.51 was 6.8.  Did not recheck the specific gravity too late and I am too tired

Fuseboxer

52.2 volts for the Daisy chain .

mcgivor

@Fuseboxer
Here is some reading material, attached pdf, which will answer many of the questions you may have. Trying to understand fragments of random information from various sources, no matter how accurate, often leads to confusion. The document is tailored for individual cells but the bulk of the information is relevant.