Sunsynk battery discharge rate

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richbee
Posts: 595
Joined: Tue Apr 19, 2022 3:39 pm
Location: Northumberland

Sunsynk battery discharge rate

#1

Post by richbee »

I've now got my Sunsynk PV & battery system working - trying to find out the best way to set it up & use it.
One thing I notice is that the maximum discharge power seems to be ~2.5kW (50A). The battery manual states normal discharge rate of 50A, with max discharge rate of 100A (max temp of 27 degrees). The inverter settings are at 90A for battery discharge, so it seems that the battery is overriding the inverter settings.
It would be very useful to be able to have 90A discharge for eg. kettle, tumble dryer, oven & hob usage when there is little or no solar input, to avoid having to use the grid when the battery is full.
Does anyone know how or if you can tell the battery to allow higher discharge rates, or if it is actually a bad idea in terms of battery life?
Solar PV since July '22:
5.6kWp east/west facing
3.6kW Sunsynk hybrid inverter
2x 5.12kWh Sunsynk batteries
1.6kWp Hoymiles East/West facing PV on the man cave
Ripple DW 2kW
Ripple WB 200W
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nowty
Posts: 5733
Joined: Mon May 31, 2021 2:36 pm
Location: South Coast

Re: Sunsynk battery discharge rate

#2

Post by nowty »

How much capacity in kWh have you got ?

Example, for Pylontech's unless you have over a specific capacity of kWh's, (3 modules of the US2000's) the max discharge rate is limited.
16.9kW PV > 109MWh generated
Ripple 6.6kW Wind + 4.5kW PV > 25MWh generated
5 Other RE Coop's
105kWh EV storage
60kWh Home battery storage
40kWh Thermal storage
GSHP + A2A HP's
Rain water use > 510 m3
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nowty
Posts: 5733
Joined: Mon May 31, 2021 2:36 pm
Location: South Coast

Re: Sunsynk battery discharge rate

#3

Post by nowty »

Reading your previous thread, I think you have 10kWh, probably 2 x 5kWh modules ?

If so, the only thing I can think of is the dip switch positions on the batteries. Are they correctly set up as master and slave.

Page 14 of the installation manual.
https://portal.wholegreenrenewables.co. ... tralia.pdf
16.9kW PV > 109MWh generated
Ripple 6.6kW Wind + 4.5kW PV > 25MWh generated
5 Other RE Coop's
105kWh EV storage
60kWh Home battery storage
40kWh Thermal storage
GSHP + A2A HP's
Rain water use > 510 m3
richbee
Posts: 595
Joined: Tue Apr 19, 2022 3:39 pm
Location: Northumberland

Re: Sunsynk battery discharge rate

#4

Post by richbee »

Thanks Nowty - I've currently only got the 1x 5.1kWh battery - maybe that is it
Solar PV since July '22:
5.6kWp east/west facing
3.6kW Sunsynk hybrid inverter
2x 5.12kWh Sunsynk batteries
1.6kWp Hoymiles East/West facing PV on the man cave
Ripple DW 2kW
Ripple WB 200W
User avatar
nowty
Posts: 5733
Joined: Mon May 31, 2021 2:36 pm
Location: South Coast

Re: Sunsynk battery discharge rate

#5

Post by nowty »

richbee wrote: Fri Sep 23, 2022 12:05 pm Thanks Nowty - I've currently only got the 1x 5.1kWh battery - maybe that is it
In that case I'd happily live with the 50A limit. :mrgreen:
16.9kW PV > 109MWh generated
Ripple 6.6kW Wind + 4.5kW PV > 25MWh generated
5 Other RE Coop's
105kWh EV storage
60kWh Home battery storage
40kWh Thermal storage
GSHP + A2A HP's
Rain water use > 510 m3
User avatar
nowty
Posts: 5733
Joined: Mon May 31, 2021 2:36 pm
Location: South Coast

Re: Sunsynk battery discharge rate

#6

Post by nowty »

I've just checked out the equivalent Pylontech 4.8kW US5000 battery and the recommended max is 50A. It does have a higher peak value but will derate if temp increases.

As an aside, the Sunsync batteries are 16 cell LFP so slightly higher operating voltage than the 15 cell LFP Pylontechs. So, if anyone is thinking of doing a DIY battery extension to them like Joeboy, you would need 16 cells and not 15 cells as for Pylontechs.
https://camelot-forum.co.uk/phpBB3/view ... =14&t=1194
16.9kW PV > 109MWh generated
Ripple 6.6kW Wind + 4.5kW PV > 25MWh generated
5 Other RE Coop's
105kWh EV storage
60kWh Home battery storage
40kWh Thermal storage
GSHP + A2A HP's
Rain water use > 510 m3
richbee
Posts: 595
Joined: Tue Apr 19, 2022 3:39 pm
Location: Northumberland

Re: Sunsynk battery discharge rate

#7

Post by richbee »

I had begun to wonder if I should add another battery now, while the first one is new, so they are well matched - but then thought I should see how it all goes first, before splashing out another chunk of money.
I don't like to see the lovely PV energy 'wasted' going back to the grid once the battery is full, but realistically it will be the law of diminishing returns if I'm already using most of the generated energy.
Solar PV since July '22:
5.6kWp east/west facing
3.6kW Sunsynk hybrid inverter
2x 5.12kWh Sunsynk batteries
1.6kWp Hoymiles East/West facing PV on the man cave
Ripple DW 2kW
Ripple WB 200W
User avatar
nowty
Posts: 5733
Joined: Mon May 31, 2021 2:36 pm
Location: South Coast

Re: Sunsynk battery discharge rate

#8

Post by nowty »

richbee wrote: Fri Sep 23, 2022 2:28 pm I had begun to wonder if I should add another battery now, while the first one is new, so they are well matched - but then thought I should see how it all goes first, before splashing out another chunk of money.
I don't like to see the lovely PV energy 'wasted' going back to the grid once the battery is full, but realistically it will be the law of diminishing returns if I'm already using most of the generated energy.
You should have bought it from the outset to avoid the VAT.
16.9kW PV > 109MWh generated
Ripple 6.6kW Wind + 4.5kW PV > 25MWh generated
5 Other RE Coop's
105kWh EV storage
60kWh Home battery storage
40kWh Thermal storage
GSHP + A2A HP's
Rain water use > 510 m3
richbee
Posts: 595
Joined: Tue Apr 19, 2022 3:39 pm
Location: Northumberland

Re: Sunsynk battery discharge rate

#9

Post by richbee »

nowty wrote: Fri Sep 23, 2022 2:35 pm
richbee wrote: Fri Sep 23, 2022 2:28 pm I had begun to wonder if I should add another battery now, while the first one is new, so they are well matched - but then thought I should see how it all goes first, before splashing out another chunk of money.
I don't like to see the lovely PV energy 'wasted' going back to the grid once the battery is full, but realistically it will be the law of diminishing returns if I'm already using most of the generated energy.
You should have bought it from the outset to avoid the VAT.
You are correct - I'm half wondering if the company might give me a discount now on a 2nd one, rather than money off my final bill for the main install - due to many many cock ups and delays - might still get away with it VAT free as I haven't paid the final invoice yet?
Solar PV since July '22:
5.6kWp east/west facing
3.6kW Sunsynk hybrid inverter
2x 5.12kWh Sunsynk batteries
1.6kWp Hoymiles East/West facing PV on the man cave
Ripple DW 2kW
Ripple WB 200W
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