question

busta999 avatar image
busta999 asked

New to site - Multiplus II & Pylontech batteries -

I have tried searching the forum but could not find an answer.

I am a total noob here so be gentle :-)

I am putting in an EV charger for the new car due in June.

I am buying a house in the next month, and I am looking at putting batteries into it and charge them up overnight and discharge over the remainder of the day.

I am looking at putting in about 20kWh of Pylontech batteries, preferably the US5000.

The house has a 100A supply.

Question:

if I put 5 x US5000 on a Victron Multiplus II - which Multiplus II (or multiple Multiplus IIs?) do I need to get to be able to charge the 24kWh batteries.


Lithium BatteryPylontech
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9 Answers
wkirby avatar image
wkirby answered ·

I don't know where you live or what electricity tarriffs you have in mind, so I'll make some assumptions based on the UK market.

5x US5000 can charge with a maximum of 250A, which is 12-13kW.
This is about 56A on a 230V single phase supply.
You could charge you battery bank up in about 2 hours from stone empty.

Charging at 250A is probably not necessary though and even the 15kVA Quattro can "only" charge at 200A.
15kVA inverter is probably overkill for a normal house and you don't need to charge in 2 hours, realistically. 4 hours on Octopus Go or 7 hours on some other economy 7 tarriff.

So 100A charge current is probably more realistic and you don't want to hammer you battery with maximum charge rate each night.

The 8kVA MultiPlus can charge at 110A or ~5.5kW - 5.8kW which is more reasonable, ~25A from your mains supply. That would be around 22kWh in the 4 hour period.

A 5kVA MultiPlus can charge at 70A. This is a popular choice as it can provide enough power for the busy times mostly. Any peaks would come off the mains to fill in.
So 70A charge is ~3.5kW and could fill your battery within 7 hours if that is the sort of tarriff you are going for.

You'll probably have more questions, but just take that in for now and fire away when you are ready.

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busta999 avatar image busta999 commented ·

yes UK :-)

Normal daily usage is 16kWh per day, peaking at 20kWh once a week.

With 5 x US5000 I expect to get 24kWh of energy per day.
Looking a charging batteries/car in a 4 hour window.

EV charger should be a standard 7kWh, take three 4hr sessions to fully charge car, expect it to be ‘top ups’ normally.

expect to add 10kWh pv in a couple of years.

So it looks like a 8kVA, or better still 2 x 5kVA, which will give me more flexibility, and could add further n

batteries later.




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nickdb avatar image
nickdb answered ·

Avoid the 5000 series. You'd be better off with more 3000C's or rather any of the other battery vendors with way better discharge rates.

20kWh is pretty basic to keep an energy efficient house going, depending on your use of gas or other power sources, let alone trying to charge an EV.

Do some proper sums before you commit.

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busta999 avatar image
busta999 answered ·

@nickdb

Consume an average of 16kWh a day. (after a 1 yr programme of energy consumption reduction/optimisation, have brought average down from 32kWh to 16 kWh, currently running at 14 kWh)

The car will charge during the 4 hr cheap rate energy overnight.

Will take 3 nights to fully charge car, I’m ok with that.

I expect to add a 10kWh pv array in a couple of years.

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Jason - UK avatar image Jason - UK commented ·

@Busta999 are you in the UK? Im near Portsmouth and it sounds like you are aiming for the same set up I im in the progress of installing. I have Multiplus 2 GX with 20kWh or storage & a 6kW PV array. New EV charger coming soon as well for increased charging rate. I used about 13kWh per day in the summer, 27kWh in the winter.

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busta999 avatar image busta999 Jason - UK commented ·
This for a new house, new to us, 50 years old to everyone else :-)


When we move we will be consuming 10-11kWh for 20 hours of each day.


The hot water and heating are managed by an old gas combi boiler. The showers are elec so daily hot water demand is extremely small.


Installing 4 x 5kWh Leoch batteries which will give me 20kWh 100% DOD, with the Multiplus II 5000 I will be able put 14kWh max per day in the 4 hour cheap rate period.


On days where we use less than 14kWh (about 5 times a month) the batteries will get topped up more and should quite quickly hit the 20kWh max load, giving us a nice contingency.


Average daily DOD will be ~50% coupled to storing batteries in ulitity room in an insulated, automated ventilated cupboard to maintain optimum 25c, should ensure a long life.

The new EV will also charge in the 4 hour cheap rate period, and will take ~ 10 hours of charge from 0% to 100% over three nights. Realistically it will be maintained between 20-80% so will top up to 80% most nights.

The Victron system and batteries have an ROI of ~ 5 years, less if we use more energy/charges go up.


The batteries are over specked because I expect to drop 4kWhp on the roof soon and I can blend cheap rate/solar together to look at heating hot water/heating house.


Very early days in this.



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Jason - UK avatar image Jason - UK busta999 commented ·
My house is a 1966 house so middle aged in the grand scheme of things. I have a ASHP for heating & hot water with a 250ltr cylinder so for me, I charge my HWS during peak solar generation and sometimes during my 4h off peak electric period at 5p per kWh. When i joined the Octopus Go tariff, I managed to move over 50% of my electrical usage to the 4h off-peak period. The batteries cover the peak period so all in I pay 5p per kWh if I buy off the grid, or free when the sun is out. The only killer for me is having a 5.7kW oven, That can only work off the grid because it pulls too much juice. My Mitsubishi W85 ASHP pulls at most 3kW but only in the middle of feb, other than that it pulls just under a kW for a few minutes in each hour. Im also still working things out as I develop my system.
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busta999 avatar image busta999 Jason - UK commented ·
We have moved all cooking off the oven and use air fryer/slow cooker, microwave.


The bread maker should easily move into the 4 hr cheap rate.


In the new house I am deploying zwave/zigbee energy metering sockets so I can monitor consumption better.


We have our baseline at 260wH and can account for 110wH in computers/freezer/fridge.


Keen to understand the remaining 150wH

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stefmari avatar image
stefmari answered ·

Hi @Busta999

Thank you for your question. As far as I understood Pylontech batts have their own BMS, each battery so the battery drives the charging. I am for 3000Cs which has 'a recommended charging current' as 37A with a max of 74A! for 60s. Obviously we should forget about 74A max charging current.


In real world, the question is: what does it mean 'recommended charging current of 37A'? Is this value the charging current as 'continuous charging current' to which 3000C battery shall ask inverter to charge or the charging current is a kind a charging curve depending on battery's temperature and many other things. At 48V with 35A 'continuous charging current' you can start charge (from 10% empty) a 3.5kW (3.37kW in fact) to 95% full in almost (48V x 35A = 1.680kW so 3.3kW/1.68kW) in total around 2hours. This is the theory at least... but reality might be different.

Can anyone of this forum confirm such a charging curve for Pylontech 3000C?

Kindest Regards,

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lackland avatar image
lackland answered ·

Be aware that Victron limit the charge current in order to be kind to Pylontech batteries. This limit (for the whole stack) is 25A for US2000, as stated in other threads here, and seems to be 50A for US3000.

EDIT: not correct, see below

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netzerodude avatar image
netzerodude answered ·

Very informative post to someone who is also looking to run a similar setup and also running steeply up the learning curve. I have looked mostly at the range of Pylontech batteries US3000 to 5000 and there seems to be a range of pro's and con's. I also want a circa 20kWh system but have only 5 hrs to charge from depleted to 100% on EDF GoElectric35 which means a charge rate of at least 4kW's. I am concerned about the @Lackland post above and wonder if there is a setting that needs to be adjusted in the Victron 48/5000/70 as charging cannot reasonably be limited by a single US3000 characteristics? I understand from other posts that Pylontech batteries are charge limited by temperature and they need to be above 15degC in order for the BMS not to throttle the charge. Our house has a very big load, fully electric, so I am actually looking at the Victron 48/8000 in case I choose to increase beyond 20kWh, but now questioning if either the US3000 or 5000 BMS limitations make this choice useless. I would welcome any comments @WKirby. Thank you in advance.

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sharpener avatar image
sharpener answered ·

@NetZeroDude also have a look at the Pylontech Force-L2. An MP48/5000 will definitely put 70A into them so two modules charge in about two hours.

Two stacks of three would be rated at 21.3 kWh and an MP48/8000 would charge them in 5 hours so a good match to your spec.

Not sure though if the MP48/8000 has UK type approval yet. But 2 x MP48/5000 is only a fraction more expensive and you could start with one and grow the system as and when

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lackland avatar image
lackland answered ·

Sorry, I was wrong about Victron applying a 50A limit to US3000C. I found I had 50A set in the VEConfigure charger tab and it allows me to increase this to a maximum of 70A for my 48/5000/70.

Re the 25A limit: this is described in the Pylontech compatibility document – The maximum charge and discharge current is limited to 25A, but the data sheet tells me the maximum is 100A ... The maximum current is limited to keep the battery healthy and reach the 10 year guarantee.

This 25A appears to be per battery, not for the whole stack. We have to assume this is the same for US2000/3000/5000.


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lifeingalicia avatar image
lifeingalicia answered ·

Be aware these are rated max values. I highly recommend not to use equipment to max over extended periods. Losses and wear on hot running equipment are significantly higher. Bats on SOC ocillating 30 100% last longer then 0 100....

Yes oversizing is more capital but extended lifetime drops price per kw/h..

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