New to solar

daromer: I was kind of half asleep when I posted that. Thanks for spotting and correcting that mis-post. I think I was thinking one thing, and my fingers decided to type something else :p

The limitation would be voltage, as the components in the panels can only handle so much voltage. Though, I'm sure they can only handle so much amperage as well.

However, to correct my earlier post, Series increases voltage, Parallel increase amperage. So, the limitation in series would be a cap on voltage, not amperage.


Good gathering there, especially for $600! And so close. To bad we can't all be that fortunate. Keep us posed, Wattsup :)
 
Nice going, all the fiddly bits add up and getting most of it at one go is excellent.

You might want to consider paralleling that grid tie inverter with whatever inverter you run off your powerwall and see if you can spoof it into working with the powerwall setup.
 
Hi all,
It's time to setup my 48 volt system with the lifepo4 cells.
First off I'm thinking the PCM60X for the cjarge controller, it seems to have enough parameter control for these batteries.
Are there any others I should look at?

Budget is a big factor right now.

I'm thinking this will be fine for my 1.5 kw system.

For the money I don't see many other options.
Those with this controller, are you happy with it?
Cheers
 
On LifePo4 batts i have 2 recomendations. (note recomendations...)
1. Make sure you can controll your charger externaly.
2. Make sure you have some sort of voltage monitoring on the cells

Then you may say: Why?? :)

So let me just quickly try to explain. LiFePo4 in generall have a very very flat curve when it comes to state of charge. So its very very hard to know if one cell is at 40% or another is at 70% because frankly they have the same voltage in resting :)

So when you start to charge them it may look even untill you come to the end. Then 1 or 2 cells will jump high in the air very very fast and gets overcharged. Then its important to either start balancing or you need to stop the charger from actually charge for a while untill you got that cell down again.

I run LiFePo4 with MPP stuff and im trying to work out so we can do above with them as well... I have the rough idea done and have done some intital tests. Need to get some hardware to run this on to get it sorted.
-----------------------

BUT: If we skip above. The scenario is not that far from other Lithium cells in general. of course never over charge them and so forth. If you just go gently with that part the other parts when choosing a charger is that you actually can set bulk and float and perhaps even disable float.

I actually use them both on my system as is. But thats to controll the balancing in the end..
Most users set bulk and float to same voltage and that will cut of when certain current is reached and limit top voltage.


Conclusion: Your charger need to have the ability to set the voltages it charges to and preferable the max current.


Note: Do not calculate your cells for instance: 16s system and im going to go to 3.5V that should be charge stop at 3.5*16 = 56V... That can ruin them :) Due to my first recomendation. If you set it to 56 you also need to monitor it activly untill the top end voltage is flat!!

I will post an image later today how my system is balanced currently. Right now it looks like this:



image_gyzgif.jpg


State of charge: 74%

Lowest 3.30 and highest 3.38.
As you can see i have some cells above. But if i go down to 50% SOC they are all almost damn flat ::) they will be around 3.29-3.31V instead.
And imagine the difference when you reach 95% SOC. Then i have 8cellscurrently that just shoots up.
My current max voltage is 55.1V and for every 2 days goes by i can raise this by 0.1v. So it takes some time to balance this bank. (1080Ah@16s)


Alot of ramble: hope it shows how i think about it.
 
I appreciateyour ramble :p

Yes I've noticed the flat curve you mention with the 12v packs i've been playing with.

I was charging with a $20 ebay pwm controller but more recentlyupgraded to an Epever tracer mppt3210 which seems much better.

As you say the cells appear very well balanced until you get nearer the diischarge/ charge limits.

I have been fairly conservative in this area with settings at

12.6 - 3.15
13.8 - 3.45 per cell

Mainly to give a good buffer butalso because I found one cell at 2.6v one morning after running all my chargers etc through the night. The other cells weren't as low. :s

I have a voltage meter on the pack but think I will have one per cell when I set up the 48v pack/s.

Your cells are looking pretty good on that software. Sounds like a good plan gradually bringing them up!

Once I get charger and inverter I'll be getting the Batrium as well, until then I'll play it very safe.

Thanks
 
Thanks btw m8 ;) You know why!

Yes LiFePo4 is a bit tricky. As long as you are aware of the flat curve it will work well in the end. I have 2 cells out of 48 that currently is a lot higher. So have to keep a close eye on those so I don't overcharge. Its a manual work right now but need to get a automatic system for this going.



I did forget to take image of the high spots earlier. To much work today but il try tomorrow to get you the feeling on when they just pop away :)
 
No problem!

Is the Batrium system catching those cells or are the jumping too high too quick?

Is it because you are actively trying to raise the charge voltage of the pack?
 
Batrium updates several times per second so its fast enough.

Yeap im going for topcharge the pack. Though best would have been to do it in advance. I got rather large packs with 360Ah in each so it can take time since i only balance couplr of hours each day :)
 
Hi all,
I have a question, if I may :)
I posted this in a separate thread but it had disappeared this morning.


So I'm currently running a 12v 400 ah system with the 100 ah calb cells Tracer mppt and a victron 800w inverter.
I had the inverter connected directly to the battery but have now connected it to the Tracer
The problem is now I'm unable to run some smaller loads from a 12 way fuse block splitter,as the inverter wires fill up the inputs on the tracer.

My question being is there any reason I couldn't connect the fuse block to the tracer and the inverter to the fuse block?

Hope thismakes sense.

I had photos in my other post.


image_akjlmb.jpg




image_xshprm.jpg


Thanks
 
Not sure i follow. I see no issue with terminating all gears with a block in between. As long as the connection is decent and wont cause issues. I have that. Both at the battery bank and at the inverter. I nave close to 0 voltage drop on those compare to the cables itself.
 
Thanks Daromer,

I guess my main concern is I don't know how many amps the inverter draws. The fuse box is rated at 30 amp per position and120amp for the whole unit.


Ive added a couple of pics, its the unit underneath the Tracer.
 
But that you should know? The inverter is specified to a max current/watt. Just calculate on that number.
 
daromer said:
But that you should know? The inverter is specified to a max current/watt. Just calculate on that number.
Click to expand...

Should I? :p

A quick google tells me amps are equal to watts divided by volts :idea: Always learning!

So around 66 amps draw.
 
:)

Sorry if I was harsh.... I couldnt help it :p
 
All good mate. Even in your harshness you helped me out haha
 
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