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duncanct asked

Multiplus II 48/5000 with 1x Pylontech US3000C

I would like to start building a basic system with future expand-ability in mind. Currently it would just to get around our "load shedding" (Utility scheduled brownouts).

I understand that the Victron compatibility document recommends 4 x US3000C for the MP II 48/5000.

I would like to initially use the MP II 48/5000 with 1 x US3000C. My understand of the drawbacks for this setup would be:

1. Require a pre-charge circuit for the caps on the MP II when connecting the battery.

2. Limit the MP II battery charge current to 37A. (As per US3000C specs)

3. Limit the AC current draw on the supply side to less than 1 776 VA. (48v x 37A - as per US3000C specs)

Is there anything else that I am missing?


Any feedback welcomed.

TIA

Multiplus-IIPylontech
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nickdb answered ·

DVCC will limit charging c/o the BMS and GX, though hard setting limits is needed in case the GX is offline.

Is this a pure UPS setup? With ESS the batteries need to deal with the power fluctuations from loads and one battery is likely to wet the bed when a large load is turned off, since ESS tends to ignore some settings.

Loadshedding is more of a blackout than brownout. ;)

In SA I prefer the freedom won e-tower modular system - much better power handling.

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duncanct avatar image duncanct commented ·

What is the definition of a large load? Won't be drawing more than 1700VA anyway and there shouldn't be one single load that is will be the majority of that.

Initially it'll be pure UPS with a future view of adding solar.

I can think of better descriptors than blackouts too. ;)

Thanks, had a quick look at the Freedom Won systems but it seems for a similar price I could add a second US3000C and have 6.7 kW vs the 4kW of the eTower e5000. Is there a big difference in quality?

Thanks for the feedback.

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nickdb avatar image nickdb ♦♦ duncanct commented ·

With UPS only you should be fine with limits.

Most people don't run batteries down to 10%, even then the pylons have 3.15kWh usable or less if you take it to a more common 80%. When you move to ESS you will want to leave capacity in the tank for power issues. The FW has better physical density and much higher continuous discharge current, which is handy for running larger loads with fewer modules.

Like for like they are not too far apart in cost and the local support (they are made locally) is very good, with a US-based BMS.

We use pylons also, nothing wrong with them, you just get what you pay for, and with backup power, more is more :)

Batteries will last for ages so it pays to spend a little more now, if you are able to.


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