Make two IP22s load to the maximum?

[LetGrind]

Hello,

I would like to optimize my battery charging with two IP22 chargers.

I have two 12V 300AH LiFePo4 batteries connected in parallel.
I have a 100/50 MPPT with 1Kw of panels but they are insufficient for my winter consumption.

So I bought two IP22s to charge my batteries with a generator.

Everything is synchronized via a BMV 712.

Without sun, the chargers remain in bulk mode, but each charger delivers only 20A on average, instead of 30A.
With sunshine, everyone switches to absorption mode, while my batteries are still almost empty at 13V. (and the chargers stay at around 20A).

This is how my chargers are set up:

• Absorption voltage 14.6V
• Float voltage deactivated
• Standby voltage 13.5V

As they go into absorption mode too early, I’ve set the absorption time to 3 hours, so I have to unplug/replug my chargers every 2 hours to continue charging.

If anyone could tell me if it’s possible to charge at 60A with my IP22s that would be great, thanks.

[Ludo]

It should be possible…

Pls. Post screenshots of all relevant setting of mppt, bmv and ip22.

And, just for a quick test, disable the bt networking on the bmv.

[LetGrind]

Thank you for you answer.

Disconnecting the EV network doesn’t work either. I bought a BMV because I had exactly the same problem without it, and I thought it would correct this problem.

Today there’s no sun, and my MPPT shows me 3A at most. Even so, the system is in absorption mode, while the BMV currently shows me 13.48V.

Here are the screenshots of the settings:

IP22 n°1:

MPPT:

[LetGrind]

IP22 n°2:

BMV:

[Ludo]

Please switch off “battery safe” in the IP22’s

Set “duree de absorption” to ??? ( I dont see this parameter in Demo mode) is should be something like adaptive …

[LetGrind]

Hello,
I have deactivated the “battery safe” function on both IP22 chargers.
I set the absorption time to “adaptive”.
I’ve also removed the MPPT from the EV network (all that’s left is the BMV and the two IP22s on it).

As soon as I plugged them in, they started absorbing immediately this morning.
My batteries are literally 90% empty at 12.7v.

It didn’t work

Currently, the chargers deliver 22A each.

The BMV indicates a voltage of 13.23V and the chargers 13.44.

The rest of the options remain unchanged.

[Ludo]

If the wiring is too thin, the voltage drop might show a full battery at the charger, causing it to switch to absorption.

[LetGrind]

My diameters are:
From the batteries to the main bus (via the bmv): 35mm².

From the chargers to the main bus: 8.37mm².

Is this enough? I can attach a photo if needed.

[Ludo]

8.37 should really be enough, maybe you have a contact problem somewhere ?

If possible measure the voltage drop from charger to battery, should be less then 0.1V otherwise you have a problem. And pls check on DC and on AC, the plus and minus wiring.

What happens if you disconnect one charger ?

[Ludo]

@LetGrind

My batteries are literally 90% empty at 12.7v.
The BMV indicates a voltage of 13.23V and the chargers 13.44.

Here are your problems…0.7v difference between battery and charger…at 30A this will be higher.

[LetGrind]

ok, it could be the diameter actually.
The chargers’ datasheets indicate a max 16 mm² terminal (AWG6) and for a cable length < 2m Victron recommends 10mm².
I don’t know how I managed to ignore this information when I set up my system.

In terms of measurements:
The Victron application tells me:

• BMV = 13.37v
• Chargers = 13.55v

Manual measurements:

• Batteries: 13.15
• Chargers: 13.4
• BUS: 13.26

After disconnecting a charger, the remaining charger instantly sends 28A and switches to “Bulk” mode.
Measurements:

Victron application:

• BMV: 13.32v
• IP22: 13.55v

Manual measurements:

• Batteries: 13.1v
• Charger: 13.38v
• BUS: 13.18v

[LetGrind]

Here’s a photo of my rough installation:

[LetGrind]

Okay, do you have any idea what’s causing this problem?

Would increasing my cable diameter help?
Could 16mm² be the solution?

[Ludo]

You have a lot of fuses, pls. check the voltage drop here.

And, wire the plus of the bmv to the other battery, might give you a better reading

[LetGrind]

I’ve connected the BMV’s plus to the other battery, and the gap remains the same:

• BMV: 13.43v
• Batteries: 13.62v

So I took manual measurements again:

• Batteries: 13.22v

• BUS: 13.32v

• Main fuse (closest to the batteries):

  • Fuse - Batteries: 13.27v
  • Fuse - BUS: 13.31v
    These measurements are taken on the bottom terminal of the fuse. If they are taken on the top terminal, there is a difference of +0.05v, which gives:
  • Fuse - Batteries: 13.32v
  • Fuse - BUS: 13.36v

The measurements taken from the fuses of the two chargers are identical:

• Fuse - battery: 13.32v
• Fuse - BUS: 13.35v
  Idem, measurements taken on the high terminal indicate an additional 0.05v:
• Fuse (h) - battery: 13.37v
• Fuse - BUS: 13.42v

[LetGrind]

I left this morning’s settings on adaptive absorption.
The chargers have just switched to “storage” mode.
They continue to deliver 20A each.

They’re rapidly dropping to 18-16A each, so I’m switching them back to “fixe” mode, I need them to charge, I can’t run my generator every day, nor for too long

[Ludo]

If you use only ONE ip22 charger you get a clearer picture where the problems are.

You might have to re-crimp all connectors or make new connections with professional tools, tighten all bolts with a toerque wrench etc

These problems purely come from your installation.

[LetGrind]

All right, thanks.
I will soon change the diameter of my cables and pay more attention to my installation.
I’ll come back here to give some news, in case it could be useful to someone later.

Thank you Ludo for your time and valuable advice.

[Ludo]

If all fails, set the ip22 units to " power supply", the voltage to 14.2 volts.

See what happens. You can’t hurt the batteries with this setting