Recent posts

#91

New Product Ideas and Discussion / Re: Whiz Bang Senior

Last post by boB - April 05, 2024, 01:06:53 PM

Only thing I can think of that would be bad would be HIGH current that would place the input to U1 too far out of its common mode voltage range.  Any battery current that is normal should be OK.  A lower shunt resistance might help but at the expense of lower resolution on the amps being measured.

You could also raise those 1K Ohms to something higher, maybe 5K Ohms

[I will get to individual monitoring in a minute.]

#92

New Product Ideas and Discussion / Re: Whiz Bang Senior

Last post by Barry Fields - April 05, 2024, 11:08:32 AM

Ahhh yes.  Thank you.

Yeah, it would probably work fine for that.  But you can't tell which battery you are looking at since they are all combined into one amplifier.

I will get to individual monitoring in a minute.

750 uO is kind of high for the typical home or industrial power battery system but will work of course.

I use that because I plan to use 100A/75mv shunts. The circuit should work with with any 4 equal shunts. The divider R14/R15 would be select-able for 50mv vs 75mv shunts.

Before I continue, is there any combination of charge current/SOC/Rconnection that would put U1 at risk? Would different resistor values for U1 preclude that? I would not want a poor connection between the shunt and negative buss to smoke U1.
Thanks for your input.

#93

Standard non-disconnecting PV Combiner Discussion / Re: DC breaker polarity orient...

Last post by aaapilot - April 05, 2024, 10:13:10 AM

If polarized breakers are used, the more positive goes to the plus source.

What that means is for PV, the positive side should connect to the PV positive and its negative to the controller plus input.

For batteries, the positive would be the battery plus end and negative breaker end would go to the charge controller plus output.  But usually, non-polarized breakers are used on the battery side and also as  a disconnect on the controller positive PV input side.

All of our PV breakers are supposed to be non-polarized now.  I am not sure what the status is for those ?  I will have to ask about that.  We have never seen an issue with polarized breakers on the PV side.  I could be mistaken but even connected the wrong way, the current is limited and fairly small compared to what a battery can put out.  Battery current, for sure, can be a problem with non-polarized breakers in a short circuit situation.

PV combiner breakers, like fuses, should not be used as a PV disconnect.  Besides, the combiners aren't located next to the controller anyway.

boB

Hi boB.  Per your last sentence above, I would point out that Midnite still makes and sell PV Disconnects that DO use PV Combiner Breakers, namely the MNPV-Disco line of products.  I've used the MNPV6-Disco disconnect with both 150V and 300V polarized CB as designed by Midnite.  Are you saying this is not a safe way to disconnect the PV array? The instructions specifically discuss and document use of Polarized CBs. Thanks.

Dave

#94

New Product Ideas and Discussion / Re: Whiz Bang Senior

Last post by boB - April 04, 2024, 11:28:05 PM

Ahhh yes.  Thank you.

Yeah, it would probably work fine for that.  But you can't tell which battery you are looking at since they are all combined into one amplifier.

750 uO is kind of high for the typical home or industrial power battery system but will work of course.

boB

#95

Hawke's Bay / Re: Status of web access to Ha...

Last post by Wizbandit - April 04, 2024, 04:05:36 PM

I just received a rev "G" of the COMBOX circuit board last week.  I need to finish one more modification to add a 9V battery to support "safe shutdown".  Can't release any without the safe shutdown, I have crashed 3 COMBOXs from Linux file system corruptions in the last month, you think you got away with a accidental power-down but the errors in the file system compound over time and it then just crashes hard. I don't work at any of the Midnite buildings, I work from home 3000 miles away.  I had to pack up my electronics shop for remodeling and all my parts are in totes.  I can't find some parts I need to complete the hardware changes.  Add that to working in the tech support department and that leaves little time for working on the COMBOX project. Still working on some minor code issues but the big tasks are done and working fine, so far...

#96

New Product Ideas and Discussion / Re: Whiz Bang Senior

Last post by Barry Fields - April 04, 2024, 01:30:42 PM

As per your request.

#97

The Rosie / Re: Cant seem to get the SOC t...

Last post by Wizbandit - April 04, 2024, 12:25:34 PM

Purple wire from the WBjr not connected or not to the correct terminal. Defective WBjr or EXTERNAL SENSOR setting is set to something other than BATTERY like 3rd party or DC out.

I'll check the connections internal of the Rosie. Since I had the epanel come with the inverter, I'm assuming it was wired correctly from the factory. External sensor is set for battery.

What Firmware versions ?  FYI - Sometimes assembly line workers miss stuff...

#98

The Rosie / Re: Cant seem to get the SOC t...

Last post by Weldman - April 04, 2024, 09:54:51 AM

My Rosie reads SOC

#99

New Product Ideas and Discussion / Re: Whiz Bang Senior

Last post by boB - April 03, 2024, 11:17:38 PM

Any reason why the attached would not work?

I have attached the LTspice file.

What is the electrical relationship between the separate shunts and batteries ?

#100

The Rosie / Re: Cant seem to get the SOC t...

Last post by qrper - April 03, 2024, 10:12:29 AM

Purple wire from the WBjr not connected or not to the correct terminal. Defective WBjr or EXTERNAL SENSOR setting is set to something other than BATTERY like 3rd party or DC out.

I'll check the connections internal of the Rosie. Since I had the epanel come with the inverter, I'm assuming it was wired correctly from the factory. External sensor is set for battery.

Mike

Mike