Growatt SPF 5000 ES & Battery Compatibility

Mark1988

New Member
Hi,

I'm planning on getting the Growatt SPF 5000ES for my new solar setup but apparently there are some compatibility issues with certain lifepo4 batteries? I want to use a 48V battery with the new 6000 cycle EVE LF280K cells (16S) for my setup - link below for reference.

I couldn't find anything about any such battery restrictions in the manual so I'd though I'd ask here and see if anyone has had any issues with their unit?

Any help would be greatly appreciated.

Cheers,
Mark

 

radurus

New Member
Since you plan to use a battery without BMS with communication, you will have to set battery as user/custom, set voltage limits High and Low and the charging current.
SOC% will not be available but voltage.

The compatibility is an issue where a BMS with communication (CAN/RS485) is used.

(It happens I am interested for the same inverter and I have read the user manual)

Pay attention. There are many scammers on Aliexpress/Alibaba.
You will pay good price (too cheap to be true) for the batteries and you will get nothing because the order will be confirmed delivered in few days.
In fact, the order is fake and the tracking number is a script.
 

Mark1988

New Member
Yes, that's right, that's the plan however, I wonder whether the charging profile of the Inverter is not going to clash with the charging profile of the BMS...? How will the Inverter know how much voltage to supply to the BMS without there being some communication?

Also, on a separate note I have actually since decided to go with a different, larger inverter as 5kWs is not enough for my house and I don't want to go down the route of chaining multiple units (their power consumption is too large for one).

If anyone's interested, this is the inverter I intend to go with instead, it's 8kW unit and should be large enough to run all my appliances and some more.
https://voltaconsolar.com/most-popu...MokKo6eqEaP-Yrt-1HCM3A9V1PTzGEOEaAm82EALw_wcB
 

radurus

New Member
Simple speaking, the lithium charging is quite simple.
CC - constant curent
CV - constant voltage

The regulator of the inverter uses the current limitation parameter and high voltage limit to charge the battery.
Until the charge current drops below the limit, it is in CC mode the voltage being below the limit set.
After that it is in CV mode, the current dropping slowly as the battery voltage approaches to the target level.

This switch between CC/CV is natural by the laws of physics.
(imagine you have 2 lakes side by side
one with 2 meters higher.
Open an eccluse between them and the water flows tumultous from the higher to the lower lake.
The flow is limited by the gate opening.
As the level of the lowest lake rises, the flow slows down.
The formerly lower lake level cannot rise over the former higher lake)


There is one more mode (CC but 0.1C) used when the battery is depleted (below the min voltage).

If the BMS of the battery is not with communication, its role wil be reduced to protecction upon overcharge (overvoltage), overdischarge (undervoltage) , overtemperature (if exist), overcurent.
Some BMSes have balancing circuits for the cells.

You can use Lithium cells without BMS but you need to equalize them.
In time they will become un balanced and require another balancing.
You risk overcharging some which are better and risk to overdischarge those weaker.
There 2 methods for equalization: top and bottom. There are pros and cons for each.
You need to study these matters if you intend to use without BMS.
 
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