diy solar

diy solar

I used my microwave and a toaster at the same time

Aussie

New Member
Joined
Mar 22, 2020
Messages
135
Location
Qld. Australia
I used my microwave and toaster at the same time time and lost power. Itseems like my daly 250amp smart BMS shut down. I have about 53volts going into it but, maybe 1.3volts coming out. Is there a fuse in it I may have blown?
 
Microwave: 1600W
toaster: 1200W

2800W total

2800W / 53V = 53A

shouldn't have triggered a shutdown unless you were at a very low state of charge, and a cell dropped to the minimum.

The non-smart DALY need to be activated:

1654116174314.png
 
Thanks for the response Sunshine. I was showing 98% soc. I have just started using my system in the last few days. When I had checked a few hours before there were no low cells. I am sure the power loss was a result of the toaster and microwave. (Action and reaction). I had just turned the toaster on while the microwave was running and the power went out. Could my (Smart BMS have died in that moment? I'll try to short the P-to the B- terminal and see what happens.
 
Just went to do the above and checked voltage in and out , and the BMS seems to have reset itself It has been sitting without power coming in ( I pulled the fuse) for about 14 hours. I checked power in and out about 20 minites ago and no power out, and now I checked and its working. Do you think my BMS may be a dud? Or, is that how they are suppost to work? It seems like it reset itself.
 
Thanks for the response Sunshine. I was showing 98% soc. I have just started using my system in the last few days. When I had checked a few hours before there were no low cells. I am sure the power loss was a result of the toaster and microwave. (Action and reaction). I had just turned the toaster on while the microwave was running and the power went out. Could my (Smart BMS have died in that moment? I'll try to short the P-to the B- terminal and see what happens.

I used math to demonstrate that even the two items were only pulling 53A from your 48V battery. Your BMS shouldn't have tripped.

Just went to do the above and checked voltage in and out , and the BMS seems to have reset itself It has been sitting without power coming in ( I pulled the fuse) for about 14 hours. I checked power in and out about 20 minites ago and no power out, and now I checked and its working. Do you think my BMS may be a dud? Or, is that how they are suppost to work? It seems like it reset itself.

Do you have a precharge circuit for your inverter?
 
I used math to demonstrate that even the two items were only pulling 53A from your 48V battery. Your BMS shouldn't have tripped.



Do you have a precharge circuit for your inverter?
I have been using the inverter with lead acid batterys , so I have a switch to change from one bank to the other, which I did during my power outage. ( I am on stand alone solar power). The L.A. batts are on the way out. Maybe a cell, or more may be duds? I bought them as A grade but did not get the report I paid for.
 
I have been using the inverter with lead acid batterys , so I have a switch to change from one bank to the other, which I did during my power outage. ( I am on stand alone solar power). The L.A. batts are on the way out. Maybe a cell, or more may be duds? I bought them as A grade but did not get the report I paid for.

Poor connections between cells/sensing wires or a bad/low SoC cell could have tripped it. You didn't commit a crime by running both of those things at once unless they overloaded your inverter.

If they overloaded your inverter and caused a shutdown, the surge from charging the capacitors may have triggered the short circuit protection.

Again, do you have a precharge circuit?

If you're switching to lead, the lead may be charging the capacitors in the inverter thus sparing the LFP from having to precharge the capacitors.
 
Poor connections between cells/sensing wires or a bad/low SoC cell could have tripped it. You didn't commit a crime by running both of those things at once unless they overloaded your inverter.

If they overloaded your inverter and caused a shutdown, the surge from charging the capacitors may have triggered the short circuit protection.

Again, do you have a precharge circuit?

If you're switching to lead, the lead may be charging the capacitors in the inverter thus sparing the LFP from having to precharge the capacitors.
Sorry, but what is a precharge circuit?
 
When you connect an inverter to a battery, there is a massive surge of current to pre-charge the capacitors in the inverter. Many BMS register this as a short circuit and disable the battery.

Thanks for the video Sunshine. How long will the capacitors hold there charge? I turn my inverter off, turn the switch to the other battery bank, then turn the inverter back on. Takes, maybe 45 seconds. Would the capacitors still be charged?
 
Thanks for the video Sunshine. How long will the capacitors hold there charge? I turn my inverter off, turn the switch to the other battery bank, then turn the inverter back on. Takes, maybe 45 seconds. Would the capacitors still be charged?

If you said 10 seconds, I'd say they held their charge. If you said 2 minutes, I'd say they didn't hold all their charge.

45 seconds is in the "I don't know" zone. :)
 
Back
Top