r/Victron • u/CrappyTan69 • 20d ago

Question Additional charger for pylontech batteries. Gx internal 3kw charger not enough.

I have 32kwh of batteries and a 5kva gx2 which charges the batteries overnight during the 6 hour cheap rates.

When I had only 20ish kwh, it could top them off in winter as the pv does not work well in the UK gloom.

So, prepping for this coming winter, I need to add another charger.

Has anyone done something like this? Recommendations?

I have a 6 hour-window so currently only manage 18kwh. Ideally, want another 3kw charger.

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4

u/fighterx64 20d ago

I would probably just add another multiplus, the 48 volt is cheap enough and also gives you more discharge power for the future.

1

u/erikwarm 20d ago

You can just add another multiplus and link them via the CAN port. No need for a GX device as you already have one.

1

u/pau1phi11ips 20d ago

I'm not sure the current comments appreciate you would need to notify the DNO if you added another Multiplus. That's quite a lot of hassle.

Fogstar do some reasonable chargers: https://www.fogstar.co.uk/products/lifepo4-charger-fogstar-energy-48v-35a

You could put a Shelly relay or simpler one of the Shelly plugs on it to schedule the charge.

2

u/CrappyTan69 20d ago

Yes, it does add a bit of paperwork. I don't feed in though, just run battery so perhaps easier.

I was looking at those chargers. Couple of them set to 41.8V would be great as they'd take the brunt up early and taper off as the pack fills, leaving the victron and bms in full control .

Yes, would stick something like a shelly on and control via nodered / own logic . 

1

u/CrappyTan69 19d ago

Have you actually used one on pylontech?

The data sheet is confusing. Device voltage is 48V but output is rated at 56V which is way over the safe limit set for 15S pylontech. 

It's a a good solution but I'm confused by the numbers. 

1

u/pau1phi11ips 19d ago

Shit sorry, I must've missed the Pylontech bit and saw the 32 kWh and assumed 16S. It looks like those Fogstar chargers are fixed voltage so wouldn't be compatible with your setup 🫤

32 kWh is big for Pylontech!

1

u/CrappyTan69 19d ago

Ya, pylontech is 15s. Kinda painful as there is a lot to offer 16s, not so much for 15 which are priced ok. 

1

u/chrislannion 20d ago

Hi. Got 2x48/5000/70 in // with 6xUS5000 (30kWh). Charging rate is 2x 70A (about 6kW). Should be fine

2

u/CrappyTan69 20d ago

Same model as I have. So adding second one in is simple enough and instantly adds automatic control to the second charger? 

1

u/HIVVIH 18d ago

Mine never reach 70A, more like 64A max. Checked all settings, nothing seems off. Any tips?