I've recently had my solar installed and I would just like to know what would be the recommended settings for Charge & Discharge for my Sunsynk kit.

5kw Sunsynk Inverter

2x Sunsynk 5kw Batteries (BYD Cell)

12x 425w Trina Solar Panels

I've had my charge on 50amps and just changed it today to 100amps to test, and noticed the the same results so far in getting warm, it hits about 30 Celsius, normally around 25, but we had some warm weather lately.

I also don't want to damage the battries long term, so just want to check what would be the recommended settings to go for to keep my batteries at best health wise.

Anyone have answers on this perhaps, please?

100amps should be fine for 2 batteries (50amps each) as they are 0.5C IIRC. You could play it slightly safer and put it at 90 or so?

Also the max AC charge setting may be set at a value which won't allow the full 100Amps DC. 

 

I only know a way to set it on the app and not on the Sunsynk itself. 

5 hours ago, mzezman said:

100amps should be fine for 2 batteries (50amps each) as they are 0.5C IIRC. You could play it slightly safer and put it at 90 or so?

Thank you, yea currently I have Charge/Discharge on 100Amps and before Charge was on 50Amps and it would reach about 2600w to charge, now it goes to about 5000w to charge, and when looking at the temps, it's not that huge difference from when it was on 50amps, actually about the same with like a 0.1 - 0.5 difference maybe.

So just want to make sure if that is ok to leave it on 100Amps or if it would effect the battery long term health wise.

31 minutes ago, William ZA said:

So just want to make sure if that is ok to leave it on 100Amps or if it would effect the battery long term health wise.

If you stick to 100A from the inverter divided across two batteries, that's spot-on with the manufacturer's recommendation.

The nominal charge/discharge current on each battery is 50A. One battery could take max 100A if you have to, but that might shorten its life. And if you drop below that to 90A discharge, you won't get full value from the power output of the 5kW inverter, it would trip around 4.5kW.

1 hour ago, GreenFields said:

If you stick to 100A from the inverter divided across two batteries, that's spot-on with the manufacturer's recommendation.

The nominal charge/discharge current on each battery is 50A. One battery could take max 100A if you have to, but that might shorten its life. And if you drop below that to 90A discharge, you won't get full value from the power output of the 5kW inverter, it would trip around 4.5kW.

Great! thank you, so 100Amps Discharge/Charge should be good, as I've noticed on the LiBMS it shows 206amps in total it can go, but don't want to push it that far, I am happy with 100Amps if that won't cause issues with the batteries health.

Look charging at 50A even 40A each battery allows for a pretty quick charge time, I estimate around 3hours or less or good sun. 

 

Batteries are a proper unknown for longevity and it's a sales brochure market. No one know what will happen in 10 years... Make it work for you and be happy and comfortable.

 

I reckon in in 6 years from now lot of issues will start to show on these "amazing" lithiums. 

 

 

 

28 minutes ago, Dylboy said:

Look charging at 50A even 40A each battery allows for a pretty quick charge time, I estimate around 3hours or less or good sun. 

 

Batteries are a proper unknown for longevity and it's a sales brochure market. No one know what will happen in 10 years... Make it work for you and be happy and comfortable.

 

I reckon in in 6 years from now lot of issues will start to show on these "amazing" lithiums. 

 

 

 

Great, thanks for the info! Yea, guess it's really hard to know as no real history yet on this what is good and what not, without looking on the marketing brochures. 

Edited December 2, 20223 yr by William ZA

Hi, I'm a little late to this conversation, but after 5 years with a 5kW Solar Circle inverter, 8 335W Canadian Solar panels, and two 4.8kW lithium-ion batteries, I loaded WatchPower for the first time today and learned that the PV charging remains at its highest at 1199W. That seemed quite low, given that my panels should be able to provide 2.6kW of input. It takes about 6 - 7 hours to recharge my batteries from a 60% capacity. If I set it to 100A or 90A, wilI it recharge my batteries faster? I see that the maximum charge is set to 50A, but when I tried to change it, the WatchPower app wants a password. I am a first-time user and never set a password for the app. Anyone know the standard password for the app?

Thanks in advance

On 2022/12/01 at 12:44 PM, William ZA said:

I've recently had my solar installed and I would just like to know what would be the recommended settings for Charge & Discharge for my Sunsynk kit.

5kw Sunsynk Inverter

2x Sunsynk 5kw Batteries (BYD Cell)

12x 425w Trina Solar Panels

I've had my charge on 50amps and just changed it today to 100amps to test, and noticed the the same results so far in getting warm, it hits about 30 Celsius, normally around 25, but we had some warm weather lately.

I also don't want to damage the battries long term, so just want to check what would be the recommended settings to go for to keep my batteries at best health wise.

So for best health, you want to charge at max 0.2C (1C = 200amps), so 0.2C = 40amps. However as many have said here, charging up to 100A should be ok. If you want to improve the lifespan of your batteries even further you could also lower the charging voltage. They will take longer to fully charge, but lifespan will increase.

Edited September 3, 20241 yr by HendrikBigChief

@DennisM

You can adjust the settings from the Inverter screen menu. Just download the manual from www, and adjust the charge setting (normally setting No. 2 & 11, but could vary, depending on your specific model)

Hi all need help got 8.8 sunsyk with 4 x 7.4 MD lithium batteries need to charge the batteries quicker as I have 270 x 20 panels thanks 

Hi all,

Came across this post when googling and am hoping someone can help.

I have a Sunsynk 5kw inverter and 1 5.32kw Sunsynk battery

I am trying to determine if my charge / discharge settings are correct. Some say it should be 50A charge for a single battery? At the moment it is 40A. What is right?

Am I getting the most of solar charging with these settings?

40 minutes ago, Bucks_Fizz said:

Hi all,

Came across this post when googling and am hoping someone can help.

I have a Sunsynk 5kw inverter and 1 5.32kw Sunsynk battery

I am trying to determine if my charge / discharge settings are correct. Some say it should be 50A charge for a single battery? At the moment it is 40A. What is right?

Am I getting the most of solar charging with these settings?

Provide the details of your panels connected in order to get better guidance.

43 minutes ago, Bucks_Fizz said:

Hi all,

Came across this post when googling and am hoping someone can help.

I have a Sunsynk 5kw inverter and 1 5.32kw Sunsynk battery

I am trying to determine if my charge / discharge settings are correct. Some say it should be 50A charge for a single battery? At the moment it is 40A. What is right?

Am I getting the most of solar charging with these settings?

At your current charge settings, you will fully charge your battery in 2 hours give or take. You probably could do 50A but what does the datasheet say? Typically the higher the charge current the less life you get out of the batteries also. If you go overboard you could kill your battery cycles quicker. The datasheet will tell you everything. I would leave it as is.

27 minutes ago, Denns said:

At your current charge settings, you will fully charge your battery in 2 hours give or take. You probably could do 50A but what does the datasheet say? Typically the higher the charge current the less life you get out of the batteries also. If you go overboard you could kill your battery cycles quicker. The datasheet will tell you everything. I would leave it as is.

Interesting that you get to 2hrs charge time without the PV size or load or some other details.

Hi,

8 x 460 panels

Datasheet of Sunsynk 5.32 says nominal charge 50a. The installer had it set at 40a since commissioning the system.

So was just wondering if it was done optimally

1 hour ago, Bucks_Fizz said:

Hi,

8 x 460 panels

Datasheet of Sunsynk 5.32 says nominal charge 50a. The installer had it set at 40a since commissioning the system.

So was just wondering if it was done qqqqoptimally

I don't think it matters much. May as well just keep it lower. There's enough time in the day to charge full up. In theory you'd be limiting to 2kW charge instead of 2.5kW, when your solar peak at mid-day could be 3.6kW. Only if you find that your battery is not charging full up, then change it to 50A but I don't think you need to.

3 hours ago, Scorp007 said:

Interesting that you get to 2hrs charge time without the PV size or load or some other details.

Well surely he won’t be asking about increasing the charging current without the solar to back it up? And 2 hours is easily doable at 40A. Thats about 1.9kwh. About 3.8 in 2. Assuming 80% discharge the battery will be about there.

5 hours ago, Denns said:

You probably could do 50A but what does the datasheet say? Typically the higher the charge current the less life you get out of the batteries also. If you go overboard you could kill your battery cycles quicker. The datasheet will tell you everything. I would leave it as is.

Agreed.

The Sunsynk guarantee on their batteries is conditional on the batteries being operated at 25 degrees Celsius, and charged/discharged at a low current (0.2C if I remember correctly). In real-life terms, one should balance the need for longer life (i.e. charge/discharge cycles) with operating within the "Goldilocks zone" (20-30 degrees) and not charging or discharging too rapidly.

Charging or discharging the battery at 50A (0.5C) or less should not stress it too much, and should result in a significantly longer service life than charging and discharging at 100A (1C). If the battery's operating temperature exceeds 30 degrees then it becomes even more important to limit the charge/discharge current.

Thanks to all for the advice. Will put on 50 for a couple of days and monitor to see if any benefit or not. Still within the battery specs.

10 hours ago, Bucks_Fizz said:

Thanks to all for the advice. Will put on 50 for a couple of days and monitor to see if any benefit or not. Still within the battery specs.

I doubt if you will see any benefit over a few days, apart from charging the battery quicker (which might, or not, be a benefit, depending on your particular conditions.

Hi all, having read most of this thread, it seems I am having pretty much the same issues as everyone.

The only query I have if anyone can help is as follows;

Does my 32A breaker on my consumer unit for the inverter prevent me from setting my charge/discharge rates higher than 32A?

I have a 3.6 inverter with a 10.6kwh battery and 16 solar Pv’s that can produce 6880kwh.

Any advice would be much appreciated.

On 2025/10/20 at 1:16 PM, Boltonclaret said:

Hi all, having read most of this thread, it seems I am having pretty much the same issues as everyone.

The only query I have if anyone can help is as follows;

Does my 32A breaker on my consumer unit for the inverter prevent me from setting my charge/discharge rates higher than 32A?

I have a 3.6 inverter with a 10.6kwh battery and 16 solar Pv’s that can produce 6880kwh.

Any advice would be much appreciated.

Currently only charging at around 1.8kw/h from solar or grid, so would like to charge a lot faster when solar is producing plenty. Not an issue at the minute in November as not enough sun to make a brew! :-D

Edited November 28, 2025Nov 28 by Boltonclaret