Rosen 48 volt 200amp/hr loosing Amp/hrs and SOC dropping each day

[FilterGuy]

To precharge just put that light set up I made in line with battery + and the + on the inverter. What should happen lights go on and then go out?

I have always used resistors, but others on the forum say the bulb will glow briefly then go out.

 

[Baja John]

I have always used resistors, but others on the forum say the bulb will glow briefly then go out.

Was wondering rather than round up 4 12volt acid batteries and join them to make 48 volts do you think I could use just a 12 volt and see if I get a short condition or would I have to apply 48 volts?

 

[FilterGuy]

Hmmm.... I guess if you put on 12v and a fuse pops, it is a good indication the inverter is shorted. However, if the fuse does not pop, I don't think you can assume the inverter is good.

 

[Baja John]

Hmmm.... I guess if you put on 12v and a fuse pops, it is a good indication the inverter is shorted. However, if the fuse does not pop, I don't think you can assume the inverter is good.

Go with the 48 volts then I am thinking you thinking 48 volts better? I seen the growatt does have setting for flooded batteries so that is a good thing. All I have are 12volt car fuses that not going to work?

 

[FilterGuy]

All I have are 12volt car fuses that not going to work?

If there is absolutely no load on the inverter and you pre-charge the capacitor you can use a 20A auto fuse to see if the inverter powers up. You would not be able to put much of a load on the system before the fuse popped and if you get a strong charge current from the Solar the fuse could pop.

 

[Baja John]

If there is absolutely no load on the inverter and you pre-charge the capacitor you can use a 20A auto fuse to see if the inverter powers up. You would not be able to put much of a load on the system before the fuse popped and if you get a strong charge current from the Solar the fuse could pop.

My thought is just to get a regular battery with no BMS or such and see if the short happens or the inverter will light up. I will leave my solar off and have no load to the inverter at all. Think one 12 volt car battery will work for that or go with the 48 volt way.

 

[FilterGuy]

My thought is just to get a regular battery with no BMS or such and see if the short happens or the inverter will light up. I will leave my solar off and have no load to the inverter at all. Think one 12 volt car battery will work for that or go with the 48 volt way.

I have never tried it, but a 48V inverter probably will not light up with only 12V on the input. Having said that, there is a small possibility it will. It depends on the power supply circuit for the control logic.

So...
1) if you try a single 12V battery and the inverter turns on, it is a good sign the inverter is good.
2) If you try a single 12V battery and the inverter does not turn on and the fuse does not blow, it does not tell you much.
3) If you try a single 12V battery and the fuse blows, the inverter is probably shorted.

 

[Baja John]

I have never tried it, but a 48V inverter probably will not light up with only 12V on the input. Having said that, there is a small possibility it will. It depends on the power supply circuit for the control logic.

So...
1) if you try a single 12V battery and the inverter turns on, it is a good sign the inverter is good.
2) If you try a single 12V battery and the inverter does not turn on and the fuse does not blow, it does not tell you much.
3) If you try a single 12V battery and the fuse blows, the inverter is probably shorted.

We are thinking the same. Think I am going to try the 12 volt and work my way up in steps hoping to get a no short situation and a inverter light up maybe at the 48 volt hook up. A short is a short and a 12 volt is going to blow a 20 amp fuse just as well as a 48 volt. Just need to know if the battery is the issue or the inverter. Will post as I go. Thanks

 

[Baja John]

No solar or load on. I hooked up my 12 volt test light and it would not go out. Hooked up the one 12 volt battery and it blew the 20 amp fuse right away same with a 30 amp. That wouldn't be caused by the capacitor would it. I am thinking the inverter has a dead short.

 

[TorC]

The reason the light goes out when precharging is because it works on the flow of power. An empty capacitor looks very like a dead short. The capacitor, however, fills up, and as it does so the voltage in it rises, looking still about like a dead short, but to a voltage closer to the battery voltage. As the that happens, the light resistance stays the same, so less power flows across, and hence the lamp dims.

Until the inverter is turned on there should be only maybe a small discharge resistor across the capacitor, just so it doesn't stay dangerous for a long time. From what you're describing it sounds to me like there's a dead short somewhere in the inverter.

 

[Baja John]

The reason the light goes out when precharging is because it works on the flow of power. An empty capacitor looks very like a dead short. The capacitor, however, fills up, and as it does so the voltage in it rises, looking still about like a dead short, but to a voltage closer to the battery voltage. As the that happens, the light resistance stays the same, so less power flows across, and hence the lamp dims.

Until the inverter is turned on there should be only maybe a small discharge resistor across the capacitor, just so it doesn't stay dangerous for a long time. From what you're describing it sounds to me like there's a dead short somewhere in the inverter.

 

[Baja John]

So if and say the Inverter shorted out and that was the big pop I heard when all shut down. Would that damage the Rosen 48 volt battery also. Is there a way to check the battery if it is shorted or damaged. When I do turn the battery on all green lights, no warnings and 52.1 volts terminal to terminal. I will have a new inverter here Monday and sure don't need to hook a bad battery to it and start all over.

 

[TorC]

The battery is supposed to have protection against being hooked to a dead short. That's one of the things that the BMS is theoretically designed to protect against.

 

[Baja John]

The battery is supposed to have protection against being hooked to a dead short. That's one of the things that the BMS is theoretically designed to protect against.

That sounds good. Not sure if this matter but I didn't have the BMS cables hooked up at the time of Chernobyl. FilterGuy and I decided to go with the program for lithium if BMS cable not used. Saying that if no warnings displayed, all cells pretty much same voltage and I can measure voltage across + and - at 52.1 all might be good? Thanks for all you wisdom. Keep this thread posted on what is what.

 

[FilterGuy]

An interesting video that loosely relates to what we are doing.... Do you really need BMS communication?

 

[Baja John]

An interesting video that loosely relates to what we are doing.... Do you really need BMS communication?

Great video.

 

[Baja John]

Good day, new inverter arrives today. Keep you posted.

 

[Baja John]

News on the fix. I installed a new inverter and all is good. Things are running fine at the moment. Will be sending inverter in to see what blew up and that should answer some more questions. Thanks for all the help.

 

[FilterGuy]

Great news. Are you getting the O-V error?

 

[Baja John]

No OV but the warning SCP. Rosen says that is a protection warning. They are so vague. Only using one battery the other has a BMS board faulty. Working on solution on getting that fixed.