Axpert invertors

Thanks for the feedback guys. Any other viable battery monitoring options other than the Victron quoted above?
 
Personally I used a Raspberry Pi + ADC. It sends me emails with updates like battery at x volts and also alerts like Utility power on/off and Backup power off (if I run out of juice before utility comes back online).

All in all cost me nothing because I already had everythink (ok well had to code some ruby but was trivial).

Might be a bit out of the depth for some because of the lack of experience with programming and ADC based voltage meter.
 
Gnome said:
Personally I used a Raspberry Pi + ADC. It sends me emails with updates like battery at x volts and also alerts like Utility power on/off and Backup power off (if I run out of juice before utility comes back online).

All in all cost me nothing because I already had everythink (ok well had to code some ruby but was trivial).

Might be a bit out of the depth for some because of the lack of experience with programming and ADC based voltage meter.
Click to expand...

Keep in mind that a pure voltmeter is not a SOC meter or battery monitor. The state of charge is a function of the voltage and the current drawn at that point in time.
 
DollyAAAA said:
Keep in mind that a pure voltmeter is not a SOC meter or battery monitor. The state of charge is a function of the voltage and the current drawn at that point in time.
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Ofc, but it is different for every battery brand and type. Even APC UPS are horrible at this (as can be read online) and they know EXACTLY the kind of battery they have, voltage, load and even track the history of the battery.

I have considered doing a basic current transformer on my inverter output (but would need another ADC, maxed out my current 4x16bit channels). Already have utility voltage, inverter voltage and battery voltages. That could be used to determine the battery load (crudely but accurate enough imo).
What is actually really cool with Rasperry Pi for example is, I can actually draw the wave form (so I technically have a oscilloscope connected to each)

This would give me something close to run-time approximation if I collect data from a few outages.

Again tho, it is so specific to the type of setup you have (and that is true for every setup imo).

Just my 2c.
 
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Gnome said:
Ofc, but it is different for every battery brand and type. Even APC UPS are horrible at this (as can be read online) and they know EXACTLY the kind of battery they have, voltage, load and even track the history of the battery.

I have considered doing a basic current transformer on my inverter output (but would need another ADC, maxed out my current 4x16bit channels). Already have utility voltage, inverter voltage and battery voltages. That could be used to determine the battery load (crudely but accurate enough imo).
What is actually really cool with Rasperry Pi for example is, I can actually draw the wave form (so I technically have a oscilloscope connected to each)

This would give me something close to run-time approximation if I collect data from a few outages.

Again tho, it is so specific to the type of setup you have (and that is true for every setup imo).

Just my 2c.
Click to expand...

Easy, bud. From you first post it didn't seem like you made any measurements other than voltage.

Do you have the model B RP?
 
DollyAAAA said:
Easy, bud. From you first post it didn't seem like you made any measurements other than voltage.

Do you have the model B RP?
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Yeah at the moment I don't measure current. I don't have a current sense transformer (I ordered a toroid from eBay, so will play with this soon) and I don't feel comfortable measuring AC current using a resistor.

Yep Raspberry Pi Model B with 4x16bit channel ADC bought from Adafruit. Two channels measure battery voltage, one measures Eskom voltage, one measures Inveter voltage. I sample at pretty low rate at the moment, so I don't have wave form information. I did some quick testing however and I can actually get the wave form when I measure at a higher rate.

As I said tho, I would need another ADC (will probably go for a 12bit) to get current on the output.
 
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Gnome said:
Yeah at the moment I don't measure current. I don't have a current sense transformer (I ordered a toroid from eBay, so will play with this soon) and I don't feel comfortable measuring AC current using a resistor.

Yep Raspberry Pi Model B with 4x16bit channel ADC bought from Adafruit. Two channels measure battery voltage, one measures Eskom voltage, one measures Inveter voltage. I sample at pretty low rate at the moment, so I don't have wave form information. I did some quick testing however and I can actually get the wave form when I measure at a higher rate.

As I said tho, I would need another ADC (will probably go for a 12bit) to get current on the output.
Click to expand...

You can also give Electro Mechanica in Milnerton a try. They have quite a selection of current transformers.
 
Gnome said:
I have considered doing a basic current transformer on my inverter output (but would need another ADC, maxed out my current 4x16bit channels). Already have utility voltage, inverter voltage and battery voltages. That could be used to determine the battery load (crudely but accurate enough imo).
Click to expand...

The inverter already measures the voltages pretty accurately, why not use those? The current measurement from the inverter is pretty rubbish though. The update rate on the inverter's measurements is pretty low, but then the voltages don't change very quickly.

Also note that the inverter wastes quite a bit of power (very roughly 50w) so the AC power out isn't the same as the power coming from the battery. It'd probably be good enough for an approximation though. For a proper SoC meter you'd need to install a shunt on the battery.
 
scottwday said:
The inverter already measures the voltages pretty accurately, why not use those? The current measurement from the inverter is pretty rubbish though. The update rate on the inverter's measurements is pretty low, but then the voltages don't change very quickly.

Also note that the inverter wastes quite a bit of power (very roughly 50w) so the AC power out isn't the same as the power coming from the battery. It'd probably be good enough for an approximation though. For a proper SoC meter you'd need to install a shunt on the battery.
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Which inverter are we talking about now :p

I don't have an Axpert ;)

But I did recently discovery my inverter has a serial port and I can check these values (just not at a battery level).
I'm going to start using those too.
 
I just had my 5KVA Axpert installed with 4 x 260AH OmniPower batteries. The electrician who did it did not have a great deal of experience with inverter installations but I was running out of options and used him in any case. He did a pretty good job and I'm satisfied. I had to help along the way with suggestions taken from reading the manual and reading this thread.

I did source a 125A fuse and fuse holder from Sinetech. Mike Stiles from Sinetech has been terrific. Also have a Gewiss GW92033 breaker between battery and the inverter which the electrician says is fine for DC as well.

So here are a few questions.

1. The electrician has used 10mm cable from Main DB to inverter, is that appropriate?
2. The electrician has used 2 x 10mm cable for all the DC connections ie. from inverter to battery and between the battery terminals, is that appropriate?
3. From where does one get those lights that indicate power is active?
4. Who in the Midrand area can verify that the installation is compliant?
5. What does the circuit breaker button on the inverter do?
 
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quinn_the_eskimo said:
1. The electrician has used 10mm cable from Main DB to inverter, is that appropriate?
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More than adequate.

quinn_the_eskimo said:
2. The electrician has used 2 x 10mm cable for all the DC connections ie. from inverter to battery and between the battery terminals, is that appropriate?
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IMO you should be using 50mm (0 gauge) IMO.

Everyone here has electricians doing the install.
They all seem to use standard solid core house wiring which is not adequate or appropriate for this sort of thing IMO.
You should be using stranded welding machine wire.

The are sold in standard sizes (25mm, 50mm, 75mm, etc.). In Cape Town, the 50mm went for R70 per meter (yep, it is seriously expensive, but the copper weight of it is insane).

quinn_the_eskimo said:
3. From where does one get those lights that indicate power is active?
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Everyone has their own solution here. I just used a blank insert, drilled a hole, put a LED light in there with a resistor, temperature fuse + current fuse.

quinn_the_eskimo said:
4. Who in the Midrand area can verify that the installation is compliant?
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Take some pics then we can tell you. You should have gotten a CoC. If it looks good, no reason to get someone else out on your expense

quinn_the_eskimo said:
5. What does the circuit breaker button on the inverter do?
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It is a circuit breaker :) It just looks different
 
Gnome said:
Everyone here has electricians doing the install.
They all seem to use standard solid core house wiring which is not adequate or appropriate for this sort of thing IMO.
You should be using stranded welding machine wire.

The are sold in standard sizes (25mm, 50mm, 75mm, etc.). In Cape Town, the 50mm went for R70 per meter (yep, it is seriously expensive, but the copper weight of it is insane).
Click to expand...

+1 Voltage loss on those 10mm2 panel wires is going to be insane. It's highly inefficient.


Gnome said:
Everyone has their own solution here. I just used a blank insert, drilled a hole, put a LED light in there with a resistor, temperature fuse + current fuse.
Click to expand...

If your DB accepts standard mini-din / din modules, there are more than enough options on the market to not do hacks and what not. If the DB isn't mini-din/din, then you're screwed yes - I haven't to date seen anything on the market "standard" for those old(er) boards.
 
Gnome and Savage. Thank you very much for the input.

I am going to source the cables required from Sinetech. Will 50mm fit in the Axpert btw?

The electrician used 2 x 10mm ie. he doubled up the cable, that should be fine until I can get the new cable, in other words is it a fire hazard or a risk in any way?

Also This is an amazingly useful thread. I have learnt a ton here. Thanks to all contributors.
 
2 x 10mm2 should carry the 100A odd required by the 5KVA yes - there's nothing wrong with "doubling up". It's still going to remain highly inefficient though, and you'll loose quite a lot of juice in terms of charging as well as running the load from the batteries.

In terms of getting the cables - take the measurements of the cables (and qty) you need, and ask someone to make the cables up for you. You will need cables, it must be terminated (lugged) with a specialized tool (crimper), etc. It all costs money, and a crimper to crimp 100A cable, aren't cheap. You're just going to spend a lot of money buying things and tools that you'll only end up using once in your life - more than likely.
 
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Chris,

Thanks a lot.

Sinetech do make up the cables crimped with lugs and colour coded heat shrink. I did get some from them yesterday but foolishly did not take the length into consideration and they are too short. I need to attend to the cables and then the indicator light and all should be good.
 
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