The Battery Thread (Solar / Inverter)

[wingnut771]

Quick question for anyone that can answer please. On my 24V system (two 12V batteries in series) - if I swop my AGM batteries out for drop in replacement Lithium batteries would I match these voltage specs (listed below here for a single battery) by just doubling them up when I configure my inverter? This is of course after changing my battery type from AGM to User:

• Bulk voltage: 14.4 V (so 28.8 V?)
• Float voltage: 14 V (28 V?)
• Under-voltage cut out: 11.2 V (22.4 V?). Maybe I should up this to get to my preferred depth of discharge?

Yes, series connection the voltage is doubled.

I would set low cut off around 12.5V and try set float to a low setting or off.

 

[RonSwanson]

All the BMS is doing in these battery's is cutting off if the cell voltage is too high or too low and if the load is too high and maybe a bit of top balancing when at absorption voltage.

I was responding to the question of "what do I do now if I change my AGM's for LFP, do I use "user" or leave it "AGM"".

I say, use USER setting because you can set the voltage to 14.4V instead of AGM setting of 14.1V, and can also set a less drastic low cut off off like 12V or something. Maybe even turn FLOAT off if possible.

Maybe that's what some BMSs do (I can't and won't argue, all BMSs are not created equally).
A good BMS would do a whole lot more, take a look here. It would:

• Count Coulombs in and out to determine SoC (and not use voltages despite its proximity to the cells);
• Monitor and balance the SoC of individual cells;
• Monitor temperatures and cut off current if over;
• Monitor and manage current and voltages to and from individual cells;
• Monitor and manage current and voltage to and from charger / load; and cut off if over.

In a replacement LFP, the BMS would also need to anticipate the inverter /charger expecting LA voltages and current from what it "sees" as one big dumb 24V battery, and protect its cells accordingly.

 

[JamesBoy]

Thanks for the input.

 

[RiaX]

So which lithium-ion battery brand is good does it matter ? Im in the process of getting quotes for a system. I have very little knowledge with these things. Same question with solar panels and inverter

I dont want to get ripped off

 

[Mzezman]

So which lithium-ion battery brand is good does it matter ? Im in the process of getting quotes for a system. I have very little knowledge with these things. Same question with solar panels and inverter

I dont want to get ripped off

There is a Google sheets with a list of reputable battery brands and tech specs + prices. That should help you.

Most guys on here have either the Pylontechs or Hubbles... then other good ones are Dyness + Alpha

 

[tRoN]

There is a Google sheets with a list of reputable battery brands and tech specs + prices. That should help you.

Most guys on here have either the Pylontechs or Hubbles... then other good ones are Dyness + Alpha

Pylontech has the longest run in the market and they have been tried and tested by many installers that have been in the business long.

I also think Freedom Won which is also a local brand is worth considering.

 

[valiente]

Pylontech has the longest run in the market and they have been tried and tested by many installers that have been in the business long.

I also think Freedom Won which is also a local brand is worth considering.

I am probably going for the Freedom WON eTower 5kWh x 2 to start with...

Good specs and well priced, also no need for a Cabinet as with the Pylontech ones.

 

[RiaX]

So im being quoted on the following:

Inverter is Deye 8kw
Panels are 490w Canadian solar
Batteries will be the Bluenova 12.5kwh HC battery.

Is this good ?

 

[semaphore]

Batteries will be the Bluenova 12.5kwh HC battery.

Not sure the price on this battery one website said 70K, for two Hubble AM-2 (5.5kwh each), you can get that for 50K +-. I'd go for Sunsynk over Deye, panels are pretty much the same.

 

[TheChamp]

So im being quoted on the following:

Inverter is Deye 8kw
Panels are 490w Canadian solar
Batteries will be the Bluenova 12.5kwh HC battery.

Is this good ?

General consensus is that anything Blue Nova is expensive, nothing wrong with it but there are options.

 

[RiaX]

and the panels ?

 

[TheChamp]

and the panels ?

Canadian Solar is the Boss, you can never go wrong with them.

 

[sandwitch]

and the panels ?

Don't get poly. Get mono.
Canadian Solar, Jinko, and JA solar are the big 3 here. They're all good. JA Solar is very efficient, and so's the Jinko Tiger series.

 

[thehuman]

So im being quoted on the following:

Inverter is Deye 8kw
Panels are 490w Canadian solar
Batteries will be the Bluenova 12.5kwh HC battery.

Is this good ?

Think of changing to sunsync 8kw instead of deye , they similar but it serms support is better, more mybb members have Sunsync too.

 

[Snyper564]

So im being quoted on the following:

Inverter is Deye 8kw
Panels are 490w Canadian solar
Batteries will be the Bluenova 12.5kwh HC battery.

Is this good ?

Need to compare apples with apples and also mention price.

 

[RiaX]

Sunsync vs deye ? why is sunsync the preferred choice here?

Yes I can google but I rather get real world experienced opinions

 

[AchmatK]

Sunsync vs deye ? why is sunsync the preferred choice here?

Yes I can google but I rather get real world experienced opinions

The user interface on the sunsynk is far superior to that of the deye

 

[RiaX]

I think then i'll settle for the deye since the company I'm using is experienced with dealing with it.

Thanks guys you've been a great help. Let me get the input from the company with the other batteries and see what happens

 

[AchmatK]

I think then i'll settle for the deye since the company I'm using is experienced with dealing with it.

Thanks guys you've been a great help. Let me get the input from the company with the other batteries and see what happens

Support for both is on the same WhatsApp group.

Some pics of the user interface of the sunsynk.

Have a look at the deye interface before deciding.

 

[RiaX]

that looks very complicated for me