Branchement easysolar-II GX a trois batterie Batterie lithium LiFePO4 rackable PYTES E-Box 48100R TE

Bit of a familiar-sounding situation here — wanted to share my own experience because I've seen this pattern crop up a few times with rack-mount LiFePO4 systems.

When I first commissioned my setup (three cells in a bank, similar topology to the PYTES units), the inverter-charger refused to wake up and the battery voltage was reading nonsense — well below what it should have been. Turned out the BMS on each unit hadn't been properly "woken" before connecting everything up. These rack batteries often ship in a deep sleep/storage mode to prevent self-discharge during transit, and until you send them the correct wake signal (usually a brief charge pulse or pressing the activation button on the unit itself), the BMS keeps the output FETs open. Hence the low voltage reading — you're essentially seeing bleed-through rather than actual pack voltage.

Things I'd check in this situation:

• Are all three PYTES units individually activated? Each one needs waking independently before paralleling
• Check the communication cables between the batteries and the EasySolar — if the BMS-to-inverter comms aren't established, Victron kit can refuse to engage
• Verify your DC cabling polarity and that the main fuse/breaker on the battery side is actually closed
• Solar voltage being present at the panels means very little if the MPPT hasn't got a live battery to charge into — it'll just sit there doing nothing

The Victron ESS documentation is actually quite good on pre-commissioning checks. Worth downloading the EasySolar-II GX manual and going through the BMS assistant setup step by step before assuming there's a hardware fault.

Anyone else dealt with PYTES wake-up issues specifically? Curious whether the newer firmware has improved the automatic wake behaviour.

Great share @FormerMechanic68 — looking forward to hearing the rest! The EasySolar-II GX with PYTES batteries is a fairly tidy combination when it's all singing together, but the devil's absolutely in the commissioning details with these rack systems.

One thing I'd flag before you continue — if you're running three of the E-Box 48100R units, make sure your DVCC settings in VenusOS are properly configured and that you've set the battery capacity correctly in the GX device. It's surprisingly easy to leave it at default and then wonder why the system's behaving oddly under load.

Also worth double-checking the CAN bus termination between units — three batteries daisy-chained can sometimes cause communication gremlins if the terminator jumper on the last unit isn't set correctly.

Keen to hear what issue you actually encountered though!

Watching this one with interest — I nearly went down the PYTES route for my garden office build before settling on Fogstar Drift cells in a DIY pack.

The EasySolar-II GX is solid kit but the DVCC settings with third-party batteries can be genuinely fiddly. What comms protocol are the PYTES units using to talk to the GX — CAN bus or just voltage-based? That'll make a significant difference to how the Victron manages charge distribution across three batteries.

@FormerMechanic68 did you configure them in parallel before connecting to the system, or bring them online one at a time? State of charge mismatch between units at first commissioning causes all sorts of headaches that look like BMS faults but aren't.

Keen to see the rest of your write-up — this is exactly the kind of documented real-world experience that's actually useful.

@SunnyViking curious what swayed you toward Fogstar in the end — I went through a similar decision point for my garden office and the rack-mount form factor was genuinely appealing on paper.

Back on topic: the PYTES E-Box 48100R does have a specific quirk with how it handles the BMS communication when you're daisy-chaining three units. The DVCC settings in the GX portal need to be configured carefully — if you let each battery negotiate independently rather than setting a shared CVL/CCL you'll get the units fighting each other and the EasySolar will log phantom alarms.

Make sure you've got the RS485 comms cable running master-to-slave correctly (PYTES documentation isn't brilliant on this). Victron's DVCC guide on the community portal fills in most of the gaps their manual leaves out.

@FormerMechanic68 don't leave us hanging mate, that "t" is doing a lot of heavy lifting at the end of your post 😂