OK that looks correct, but how are you only reading 8.8 volts at the 16.8 terminal?

 

hi sg,
Your link is reporting an Error. 404
E

 

hi sg,
Your link is reporting an Error. 404

Hi E,
What Link is that?
I'm not the TS.

 

hi sg,
You have edited your post, after I posted.
E

 

Okay I think I’m having a issue with the connection at the batteries. Now I’m getting 14.8v on my new batteries and 13.0v on my test batteries. I’ll reconnect everything and give it a try.

 

hi sg,
You have edited your post, after I posted.

OK I see. Yes I deleted the drawing after I saw post #20.

No Problem.E

 

Okay I think I’m having a issue with the connection at the batteries. Now I’m getting 14.8v on my new batteries and 13.0v on my test batteries. I’ll reconnect everything and give it a try.

okay I tried it again and the relay will not kick over so I’m thinking that the bms cannot take the draw that the really is pulling. So if that’s the case I think a 5v 4 pin relay will work

 

I tried it again and the relay will not kick over so I’m thinking that the bms cannot take the draw that the really is pulling.

That can't be true unless the BMS is defective.
Takes this one step at a time.
Connect the battery pack directly to the W1209 with out the BMS or Solar Panel connected and see if the W1209 works.

 

That can't be true unless the BMS is defective.
Takes this one step at a time.
Connect the battery pack directly to the W1209 with out the BMS or Solar Panel connected and see if the W1209 works.

Power from batteries to W1209 is good it engages the relay.
Powerr from the BMS output terminals 8.8volts to the W1209 and it’s not engaging the relay.
The light comes on when indicating the relay should be engaged but no power to the fan. I’ve contacting the seller of the BMS so I’ll hopefully see a replacement sent. Last is there alternative setup for the same application of the solar and batteries ?

 

Powerr from the BMS output terminals 8.8volts to the W1209 and it’s not engaging the relay.

The W1209 says it will operate between 6 and 12 volts. Maybe it's the fan that will not operate on 8.8volts.

 

The W1209 says it will operate between 6 and 12 volts. Maybe it's the fan that will not operate on 8.8volts.

Maybe so..... If worse comes to worst I could swap the relay out for a lower 5v relay. Just a guess. The BMS seller said he would be shipping a newer upgraded one to replace this one so I’ll check that too.

 

If worse comes to worst I could swap the relay out for a lower 5v relay.

Possibly. Interesting about the specs on the W1209. After closer examination I see there is a 12 volt relay on board. That might explain why it would not work on 8 volts.

 

After short time of debating if the new BMS cannot supply the full 12v as needed I feel that a simple solution of just switching the 12v relay on the W1209 board with a 5v relay will fix that issue. Thank you all who posted and thank you sghioto for your help. When the new parts come in I’ll post a update.

 

Okay long awaited news I just received my new bms and I’m receiving the same output of voltage as the last bms (9.8v). So my solution is to replace the 12v relay with the 5v relay and that solves that problem. Now I had another question maybe someone can help me with where to connect a battery capacity indicator on the existing wiring diagram ? Thanks again all.

 

Okay long awaited news I just received my new bms and I’m receiving the same output of voltage as the last bms (9.8v). So my solution is to replace the 12v relay with the 5v relay and that solves that problem. Now I had another question maybe someone can help me with where to connect a battery capacity indicator on the existing wiring diagram ? Thanks again all.

Okay so I’ve done some testing of my circuit found some issues that need to be fixed. The battery holder has a bad connection causing my voltage to be 9.8voots at the 14.8v terminal of the bms. So I need to fix that to get the full voltage to my thermostat. I had a question regarding the battery indicator and where it connects, if anyone can help me but I think the positive lead goes to the 14.8v terminal of the bms and the negative terminal for the battery holder is that correct ?

 

Correct

 

Does the BMS have translation errors? it says 40A and 80A peak which will blowup the battery cells to kingdom-come.
A cell at 3.7V is barely charged, 4.2V is a full charge after its charging current has dropped.

 

Does the BMS have translation errors?

I think it's capable of that much current but actually limited to about .6 amp from a 12 volt/10 watt solar panel.

 

Does the BMS have translation errors? it says 40A and 80A peak which will blowup the battery cells to kingdom-come.
A cell at 3.7V is barely charged, 4.2V is a full charge after its charging current has dropped.

Here’s the data sheet on the bms

 

I think it's capable of that much current but actually limited to about 1 amp from the 12 volt/10 watt solar panel.

It says its recommended input is 16.8V, not 12V.