Pylontech 5000 bank and 3000B bank combined?

Batteries Lithium
1

Hi All

If I add 3x5000’s to my 2x3000B’s can I do the following… (I am keen to not have all the batteries connected through just a pair of cables to the busbars…)

Bank 1 = 2x 3000B (Pylontech cables to Busbar)
Bank 2 = 3x 5000 (Pylontech cables to Busbar)

Now the question:
Run the battery link cables from 5000 (1) > 5000 (2) > 5000 (3) > 3000 (1) > 3000 (2) and so have 1 visible battery bank to the CerboGX via the CanBMS comms cable.

I can’t see any issues and have the added benefit of an extra set connections to the BusBars.

Thanks
Mark

2

The size of the inverter will determine if you need more than one cable pack, If you are fine with one now there will be no added benefit in using a second. Flip side, it can do no harm adding a second set. I will personally run one set from the first battery and the second set from the last.

I recently added a UP5000 to and existing bank of mixed US2000 and US3000. My supplier advised against it as they don’t have written confirmation from Pylontech that these three models can be used together.

To be honest, I was worried for a while as it took over 2 weeks for the bank to start “synchronising”. Now they are running fine and it seems like they are sharing the loads perfectly. Just after adding, the complete bank was acting strange with some showing empty while others were indicating “Full”.

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3

How did you see the different SOC for each?

4

Thanks Jaco. My concern is the fact that you still have the single cables between each battery in the bank (between top and bottom). So the week link(s) in my opinion.

5

Not a weak link. Your inverter can only draw a certain current, if the current cable can handle that you’ll be fine. Even if you add 20 batteries, the current that will flow through that cable wont be more, unless you add a few more MPPt’s and all of them try to charge the batteries together and the amp exceeds the rating of said cable. So what I am trying to say, if the cable is sufficient for now and the only change is adding batteries, then the cable will still be sufficient…

If it makes you feel better, add another cable pack, there is no harm in doing so.

6

Just by looking at the indication lights on them. Did not use the software that some of the form members use. It was purely based on the indication lights.

7

At some stage when I add batteries I’m going to add another MPII 5kv. So 10kv at some stages.
I am more interested your thoughts on the communications between with batteries if I have 2 banks but linked comms cables (ie make a single virtual bank). Max current flow I agree with!

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8

Presumably you just also need to take account of the charging ability of the MPPTs (if you have a Victron system) and size the wires according to that (if the MPPTs are more than the Inverter - likely in the case of larger battery banks)?

9

The last recommendation that I read and that I apply in my Instalations. Main coms cable goes to the biggest or latest battery. From there they all just link through port 0 and 1…

So imo it should be one virtual bank like you described earlier. I agree.

I am sorry, I guess I misunderstood the question.

2 Likes
10

Always good to be reminded of the limits of the inverter… :+1:t3::grinning:

11

I agree. But in Marks installation that is not the case hence this comment below.

1 Like
12

Sorry, I missed that bit!