SMA Sunny Island and Sunny boy problem

[kts78]

I am looking for some help with an off grid SMA system on a school (need it right by mid Aug). 2 6048's with a SB6.0 to charge batteries (trophy lifepo4). Has been running since May and had a few bugs initially but has been working great. This week it started shutting off and restarting -- the screen on the SI says 369 VBATMAX -- if I disconect the SB the system stays running. I am assuming it thinks battery voltage is getting too high- previously is was just slowing production down on the SB and it would just wait for a load before ramping up. Side note- we lost internet connection about 3 weeks ago so I can't see what the SB is doing. Any help would be greatly appreciated.

 

[Hedges]

I haven't encountered that.

What battery do you use? What voltage do you measure?

It seems 2xx is battery in my manual, 3xx is external. I don't find 369.
Maybe an error due to external BMS so reported as 3xx?

Perhaps charge voltage, requested by BMS, is so high that it runs to over-voltage.
Maybe reducing target battery settings in BMS will leave some headroom.
If running open loop with lithium battery (VRLA settings on SI), then lower voltages in SI?

Could be some cell imbalance has developed, so voltage runs faster.

Without internet, should be able to connect a PC locally. Or use front panel to read some paramters.

"20.5 Display of Failures and Events
Each failure and each event have a unique three-digit display number that is created according to the
parameter/measuring value assignment. The events and failures have the identical numerical range:
• 1xx - INV - Inverter
• 2xx - BAT - Battery
• 3xx - EXT - Extern
• 4xx - GEN - Generator
• 5xx - GRD - Grid
• 6xx - RLY - Relay
• 7xx - SYS - System
• 8xx - AUX - external devices and components"

 

[kts78]

yea, I couldn't find 369 in the manual either. Open loop. Batteries are Trophy 220amp. I will have it reconnected with internet next week, it should allow me to see what's going on with the SB. Previously it was always ramping down input. I have noticed if the batteries are not at 100% I will not get this error. What I don't get is why it was working fine for 2 months batteries stayed charged 100% most of the time and the SB ran most of the loads (almost all load is day use only). I sent the files from the SD card to SMA

 

[kts78]

Battery voltage runs 54.25-55.70

 

[Hedges]

55.70V / 16 cells = 3.48V/cell, seems reasonable.

If cells were better balanced before, voltage rose slowly.
if some imbalanced now, voltage will run faster.

Check cell voltages on BMS.

At what voltage does BMS start to balance?

How long does SI hold voltage for absorption? I would think more time in "rebalance" range would keep cells better balanced.

 

[BushMan2000U]

I am looking for some help with an off grid SMA system on a school (need it right by mid Aug). 2 6048's with a SB6.0 to charge batteries (trophy lifepo4). Has been running since May and had a few bugs initially but has been working great. This week it started shutting off and restarting -- the screen on the SI says 369 VBATMAX -- if I disconect the SB the system stays running. I am assuming it thinks battery voltage is getting too high- previously is was just slowing production down on the SB and it would just wait for a load before ramping up. Side note- we lost internet connection about 3 weeks ago so I can't see what the SB is doing. Any help would be greatly appreciated.

I had the same issue with the Vbat Max. Hedges suggested ti lower the battery setting to 46 volts and it helped as it creates a wave of influx power , the lower voltage give the battery space to keep from hitting the VBat Max. I have a Big Battery Kong elite in open loop and it does not lie to be in open loop.
Apparently EG4 LL batteries work with Sunny Islands in closed loop , just need to download the protocol.

 

[kts78]

I had the same issue with the Vbat Max. Hedges suggested ti lower the battery setting to 46 volts and it helped as it creates a wave of influx power , the lower voltage give the battery space to keep from hitting the VBat Max. I have a Big Battery Kong elite in open loop and it does not lie to be in open loop.
Apparently EG4 LL batteries work with Sunny Islands in closed loop , just need to download the protocol.

thanks, I am finally on site and have some time to play with the settings

 

[Hedges]

I think my 46V suggestion was because 48V nominal VRLA didn't allow max/min voltages that fit the 16s LiFePO4 range.

 

[kts78]

55.70V / 16 cells = 3.48V/cell, seems reasonable.

If cells were better balanced before, voltage rose slowly.
if some imbalanced now, voltage will run faster.

Check cell voltages on BMS.

At what voltage does BMS start to balance?

How long does SI hold voltage for absorption? I would think more time in "rebalance" range would keep cells better balanced.

it starts to balance at 55v, but once it hits 55.2 the voltage climbs really fast. going to try changing system to 46v see what that does. All the other errors I have gotten are caused by the overvoltage- then inverter trying to restart.

 

[kts78]

I think my 46V suggestion was because 48V nominal VRLA didn't allow max/min voltages that fit the 16s LiFePO4 range.

I switched it to 46v yesterday morning. Looks like it will work. I started all my loads until SB had solar at full production, then shut everything off- all worked like it is supposed to. I did have to raise my charge voltage to the max of what Trophy recommends for their batteries. We will see how it does, although now sure I'll be getting a ton of sun with storm Franklin about to hit us head on

 

[Hedges]

SI has per (lead-acid) cell voltage settings. Have you looked at the numbers, calculated what they now mean for your 16 LiFePO4 cells?

 

[kts78]

Yes, I had done that before, but had to reset all the cel voltages