Elefast 330 Ah battery install, test, evaluation, etc.

[Rocksnsalt]

Original Blue Sea nut plus one jam nut on top

Ok that makes sense to me now haha

 

[bigb]

Finished my install today, the inverter wiring was a huge pain and I have the scars to prove it. I bored one hole thru the floor inside the refrigerator wall and siliconed a 1" PVC coupling (which I sanded the centering ridge out of) in it for protection, then I punched another hole in the side of the battery box for a 1.25" chase nipple with a bushing. All this to keep my conductors as short as possible but still wanted a neat looking install. I ended up with 6 feet total round trip, the Circuit Wizard said I could use 1/0 but I used 2/0 since my penetrations were big enough. I put a low voltage ring with a blank cover punched for a 1.25" bushing to bring the conductors out of the wall.

I installed an inlet which leads 6 feet to the cabinet where the microwave plugs in, when we want to use the micro on battery I will use a heavy 1" jumper cord like the one in the pic that I used just for testing, it is only AWG 16 but it worked fine to boil some water in the microwave and didn't even get warm. I have a heavier one arriving Thursday.

Tonight I need to read all my manuals for the battery, the inverter and for the new Blue Smart 12/25 charger I installed in an adjacent bay. Need to go over my Smart Shunt settings as well, and maybe there will be some recommended charger settings in the blue Smart manual.

I'm a little concerned about the location for my charger, it will get no ventilation when the compartment door is closed but I had nowhere else to put it. There's really not much room for a vent either.

 

[calbiker]

The battery looks good in there with plenty of room to spare. You don't have a battery disconnect switch? Did you notice a sizable spark when connecting power to the inverter? You may have done it, but it's best to precharge the inverter capacitors before making that connection. Using a small 12V light bulb as a resistor to limit current, connect the bulb to the inverter to charge the caps. Once charged, (it will take seconds) make the real connection. Check battery box temperature when driving. My box gets fairly hot from engine heat. I've mentioned it in previous posts.

 

[bigb]

I used a 25 watt 12 ohm resistor. Had no spark whatsoever. I do wonder though if I need to do this every time I disconnect the battery and reconnect?

 

[Lagom]

I used a 25 watt 12 ohm resistor. Had no spark whatsoever. I do wonder though if I need to do this every time I disconnect the battery and reconnect?

And what are the consequences if you don’t?

 

[bigb]

What value did you torque the battery terminals to? The manual just says "tight". I went with 100 lbs/inch

 

[bigb]

And what are the consequences if you don’t?

big spark that can damage threads

 

[calbiker]

The spark has the power of a welder and will remove metal material at the contact point. You need to precharge every time power is removed from the inverter.

I don't recall the battery terminal torque I used. I asked Elefast, but they didn't know. That is kind of an important spec. Perhaps you can make an inquiry? They may know now that it's almost a year later.

 

[RVBarry]

And what are the consequences if you don’t?

Some batteries' BMS will fault.
A long-term solution is to put a lightbulb in a parallel circuit with a pushbutton switch. Hold the button until the lightbulb dims, and then turn on the main switch.
There's more about it in my thread: https://sprinter-source.com/forums/index.php?threads/107497/

 

[bigb]

I fused my inverter with 200 amps but I am second guessing that, probably should have gone more for surge. I ran 2/0.

 

[bigb]

Am I going to be able to balance these cells with just a charger? Everything was going along fine at 6:21 PM, at 6:27 things changed and at 6:35 #3 must have hit 3.65 and shut everything down. (I had been messing with the voltage and had set it at 14.6 a minute before I noticed the alarm, not sure if this pushed #3 over limit or if it was going to anyway) I applied a load to get the charger to kick back on at 6:38 and set the voltage back to 14.2 and I will be watching it.

Is it even possible with just a charger? I have a Victron 25 amp that I can reduce to 10 amps, and the voltage is fully configurable. It is set at the default right now of 14.2. Do I need to boost that to 14.6? I also have a Victron 15 amp which I can set to 4 amps, it also has fully configurable voltage.

Can it be done or do I need a bench power supply or can I get it "good enough"?

 

[3Play]

You may have to cycle it a few times to get them to even out......
Probably not a bad cell. But it can happen....

 

[bigb]

You may have to cycle it a few times to get them to even out......
Probably not a bad cell. But it can happen....

How deep of a discharge between cycles?

 

[3Play]

How deep of a discharge between cycles?

I have not done it specifically on LifePo, I just let the system cycle it on it's own, but the charging was limited to 800w of solar at about 7A.
For LiPoly I have chargers that can do specific cycling.
If you can limit the charge and cycle about 50% you should be ok. (Look up Lifepo cycling) If it doesn't start to even out after a couple cycles, I would call the supplier....

PS, you can use 80% without reducing the life of the batt.

 

[calbiker]

You charged the battery too fast. It takes hours to balance the cells. Lower voltage to 14.2.

 

[borabora]

Assuming your Victron charger works like my Victron 17 amp charger then you can configure it to act like a power supply. I would do that and just hold the battery at 14.1V for 24 hours to see if the cells will top balance.

 

[marklg]

I have an RC charger that I occasionally use to charge the batteries to allow them to balance. It has a LiFePO4 setting and is only a few amps, seems to do the trick. I used it on each individual battery the first time.

Regards,

Mark

 

[bigb]

After the last charge completed and the battery rested overnight the cells are looking pretty even this morning at 3.334-3.336 with the resting voltage at 13.34. It had a slight load overnight with a light and the gas detector. How's this look? As good as it gets?

@calbiker My initial charge from 50% took 11 hours, are you saying I should have used a reduced charge current to extend the time and give the cells more time to equalize? I loaded it this morning at 110 amps for a minute then connected my Blue Smart 15 amp and set it to 4 amps and 14.2 volts.

 

[calbiker]

You can still do a lot better. First time balancing takes a long time. Hold voltage at 14.1 or 14.2 for the day.

 

[spaner]

Can you really expect better than 2 mill volts delta at that part of the curve with no load ? My first “top balance “ was not hold for so long so probably didn’t get the cells perfect - but after 3 years my cells ( electrodacus bms passive balance ) are 2-3mV delta which I sort of deem good enough