24v System, am l on the right track?

[LeighK]

Hi, l am looking for advice/confirmation on a 24v offgrid system l hope to build. This is what l currently have to work with:

8 x 3.2v 272ah Lishen batteries
12x 370watt Jinko panels (41.46voc)
2 x 100amp/200v Epever charge controllers
1 x Giandel 4000w/8000w 24v inverter

I am proposing to put these in a 3s2p array x 2
delivering 2200w each array, can anyone recommend or give advice on the best way to arrange the array? Thanks in advance, hoping not to blow something up!

I am a single mum, live in rural Australia and there is no specialised solar companies nearby to help so l'm on my own.

 

[GVSolar]

If you post the specs (from back label) of the panels and the model number of the charge controllers that would help. You'll need a BMS for those batteries too... I suggest you start by watching some of Will Prowse's beginner videos on YouTube. Take your time, and be safe... Lots of helpful people on here.

 

[LeighK]

If you post the specs (from back label) of the panels and the model number of the charge controllers that would help. You'll need a BMS for those batteries too... I suggest you start by watching some of Will Prowse's beginner videos on YouTube. Take your time, and be safe... Lots of helpful people on here.

Hi, thanks for responding ? l have watched alot of Will's videos but l am still unsure if l'm going to be doing it right. I have attached a copy of the panel specs (highlighted in yellow). I was going to purchase a Daly BMS 8S (not smart version).

 

[LeighK]

Hi, thanks for responding ? l have watched alot of Will's videos but l am still unsure if l'm going to be doing it right. I have attached a copy of the panel specs (highlighted in yellow). I was going to purchase a Daly BMS 8S (not smart version).

Are you able to help me work out the amps based on my initial idea of 3s2p? And with two arrays will l need a combiner box? Sorry for all the questions ?

 

[AlanH]

Leigh, have you considered a combined controller/inverter like the MPP. They are sold through a distributor in Sydney.

PIP-4024MT 4000w 24v MPP Solar inverter high PV DUAL AC output WIFI | MPP Solar

LOCAL STOCK AVAILABLE NOW Dual AC Output Max PV Input 5KW 500V Batteryless Support Built in WIFI 120A MPPT Charger Max 4Kw output 24VDC 100A Utility Charger Detachable LCD Module

mppsolar.com.au

where bouts are you located mate?

 

[740GLE]

Do you have future plans of expanding your storage?

That much solar would be great for a 48v system.

 

[GVSolar]

This may help - but much depends on the max input specs of controller and max-min local temperatures...

Solar Charge Controller Calculator

www.explorist.life

 

[LeighK]

This may help - but much depends on the max input specs of controller and max-min local temperatures...

Solar Charge Controller Calculator

www.explorist.life

Hi, thanks yes l have used this to try and work out my design (see image of findings) as each solar charge controller is 100amp/200v rated l just want to confirm that this is possible using what l have? I used a -5° although l will be insulating and heating the batteries so as to not go below 0° when charging.

 

[LeighK]

Do you have future plans of expanding your storage?

That much solar would be great for a 48v system.

One day yes definitely however for now as l have already purchased many 24v components l will stick with that for now ?

 

[LeighK]

Leigh, have you considered a combined controller/inverter like the MPP. They are sold through a distributor in Sydney.

PIP-4024MT 4000w 24v MPP Solar inverter high PV DUAL AC output WIFI | MPP Solar

LOCAL STOCK AVAILABLE NOW Dual AC Output Max PV Input 5KW 500V Batteryless Support Built in WIFI 120A MPPT Charger Max 4Kw output 24VDC 100A Utility Charger Detachable LCD Module

mppsolar.com.au

where bouts are you located mate?

Hi Alan, yes l would have liked to use one of these but l could not find a way to utilise all 12 panels without going over the volt rating for the charge controller (41.46VOC each panel) but l would have liked to for sure.

 

[nc73]

YES don't waste your time with 24v, 48v or bust. Wires etc are cheaper for 48v. Why spend money twice...

 

[LeighK]

I'm thinking l will need to run 2x 6 string combiner boxes with each going to it's individual charge controller before wiring each controller to the batteries am l right? Abit confused on this portion.

 

[AlanH]

Hi Alan, yes l would have liked to use one of these but l could not find a way to utilise all 12 panels without going over the volt rating for the charge controller (41.46VOC each panel) but l would have liked to for sure.

Leigh, it has 500v input mate. It will utilise all your panels and more.

I agree with others about 48V but thats your call

 

[LeighK]

Leigh, it has 500v input mate. It will utilise all your panels and more.

I agree with others about 48V but thats your call

When adding it up l came to 497v which l felt was a it too close for comfort

 

[AlanH]

When adding it up l came to 497v which l felt was a it too close for comfort

Leigh, with 3S2P it equals 124.5V. Ok if you double that because you said “x2), that would only be 249V. Thats 12 panels but you still have plenty in reserve with the 500voc and 120A

 

[LydMekk]

If you have bought this RECENTLY, talk with your supplier to change the electronics to 48V varieties.
All new tech coming out is based on 48V.

 

[LeighK]

Leigh, with 3S2P it equals 124.5V. Ok if you double that because you said “x2), that would only be 249V. Thats 12 panels but you still have plenty in reserve with the 500voc and 120A

Oh yes you are right!! I have attached the calculations based on the YouTuber explorist life and it came in at 133v per array but 77amps so if l have the two arrays going into the all in one unit would l double those amps which would then come to 154amps or is there something l'm missing here? I really really appreciate your help as l would love to use an all in one.

 

[LeighK]

If you have bought this RECENTLY, talk with your supplier to change the electronics to 48V varieties.
All new tech coming out is based on 48V.

I know what your saying but to do that l'll need another $2200AUD in raw cells

 

[Doggydogworld]

I know what your saying but to do that l'll need another $2200AUD in raw cells

He's saying your supplier might take back your eight 277Ah cells in exchange for sixteen 130s or something. Doesn't hurt to ask.

That MPP all-in-one unit can take 5 kW of solar input but its 24V/120A charger can only send about 3 kW of that to the 24V battery. Your panels won't put out the full 4.44 kW very often, though. And you may have AC loads to eat up any excess above 3 kW. So I wouldn't automatically rule the MPP out, even if you stick with a 24V battery. It just depends on your situation. Of course these issues mostly disappear at 48V.

 

[khal009]

I have a 4024mt inverter seems to work pretty well but but does over heat at higher end of output currently working mppsolar to work out solution I'm vic so currently pretty hot