Deluxe8000:
Pls house, what is your take on this charger as regards it's effectiveness and durability? Thanks.

I used the exact type (30 amps) for about three years on AGM cells. Charges well and the batteries lasted the whole 3 years before I switched to Lithium. So I've retired the charger.

I think it's a good charger. But await reviews from others here with more experience.

Good morning,

Please I just bought 2No 150ah inverter batteries (auction). I'd love to charge it on both solar and NEPA. Which should be my best bet(hybrid inverter). My expected load is five 30watts Fan.

I will also like to know how many hours my fans will work. Thanks

mctfopt:


Secondly, buy an appropriate SCC that can match the cut off voltage of the BMS. Eg a 24v lifepo4 (3.2v cell) BMS will cut off at voltage exceeding 28.8v, so set your SCC maximum battery charging voltage to like 28.4v or something below that 28.8v.

Finally, not ALL MPPT solar charge controller fries when the battery is disconnected during PV charging.

@bolded is a very valid solution, from personal experience. And my SCCs did not fry when the BMS momentarily shut down charging then (happened a dozen of times before I could get the sweet spot of HVD setting on the SCC). This makes me to wonder that what the BMS probably does is to disconnect, thru it's internal circuitry, charging to the battery rather than disconnect the battery from the charging terminals. That way your SCC is not left vulnerable.

My SCCs are MakeSkyBlue and PowMr.

ceaser:


@bolded is a very valid solution, from personal experience. And my SCCs did not fry when the BMS momentarily shut down charging then (happened a dozen of times before I could get the sweet spot of HVD setting on the SCC). This makes me to wonder that what the BMS probably does is to disconnect, thru it's internal circuitry, charging to the battery rather than disconnect the battery from the charging terminals. That way your SCC is not left vulnerable.

My SCCs are MakeSkyBlue and PowMr.

The BMS can be likened (in a way) to a breaker on the negative battery terminal. So the BMS opens if it senses preset low voltage, over voltage, over charge current, over discharge current, low temperature (optional feature), etc.
When it does this, the SCC is now at the mercy of the PV voltage. Unless you have an SCC that this issue is not a problem for, you are in for SCC failure. But if your system is well designed, you'll never have to bother about any of these ever happening to your setup.


Makeskyblue may not be premium, but that small SCC truly rocks!

ojeysky:


Felicity is a PIP clone, so I still get data from it for my emoncms processing (though not as much as the PIP), it's the reason I went for felicity as a temp replacement. I hope my PIP will come alive soon enough hopefully covid-19 will get past us sooner than later.

Hi. What caused the GK failure?

mank1234:


Hi. What caused the GK failure?

No idea, just got home to meet warning 32; Comms not interacting with the inverter

Folks I recently introduced BMV 712 to my setup(great tool by the way), but I noticed there is a 5A difference between what inverter display as charging current and what is actually seen by the BMV. Has anyone experienced this before?
Am suspecting it's probably wire+battery resistance but like to hear if anyone is getting actual figures on theirs (both sides)

ojeysky:
Folks I recently introduced BMV 712 to my setup(great tool by the way), but I noticed there is a 5A difference between what inverter display as charging current and what is actually seen by the BMV. Has anyone experienced this before?

Which one is higher? Are you using a victron cable or a DIY cable?

Please a little.heads up.

12v system with 24v panels thru 60A 12v/24v/36v/48v MPPT SCC 100v max input voltage.

Is it allowed to increase MPPT SCC panels input to 36v (that's 3s config assuming each panel is 12v) or to 48v input (2s if panel is 24v) and still maintain the 12v system?

If yes, does this allow safely breaching the allowable 720 watts (12v X 60amps) 60A SCC specs for 12v system by increasing the input above 720 watts or is it criminal to do it?

Thanks.

adrusa:


Which one is higher? Are you using a victron cable or a DIY cable?

When charging inverter is higher but when discharging BMV is higher. Yes am using victron cable

NiyiOmoIyunade:
You should use a cable size vs distance chart.


In general;

10MM2 Cable is rated for about 40A Max

16MM2 Cable is rated for about 60A Max

For your specs you are better off with 25mm2 from each CC to battery and then 35mm2 mimimum for your *common* battery interlink or bus bar distribution.

For the CC yielding 18amps, you can cheap out and keep 10mm2 cable but as you add more panels, you will ultimately upgrade to thicker gauge cables - might as well bite the bullet at once

Best option is to bite the bullet and going 35mm for the current set up.

But what happens if I decide to put a 3rd 60A MPPT SCC and maxing it out, thereby jacking up the SCC terminal to battery terminal current from 120A to 180A.

Is that a safe current to have around?
Is that safe for 35mm cable?

ojeysky:


When charging inverter is higher but when discharging BMV is higher. Yes am using victron cable

Check with a clamp meter to see who is telling the truth and use that to calibrate the BMV. Calibrate your inverter too if that is possible.

Internal calibration and measurement accuracy.

I find the Victron BMV to be pretty accurate and asian origin equipment to be very inaccurate when it comes to measurement.

Two things you are battling when measuring voltage or current from an inverter

1) Increased resistance and Voltage drop as you pass large currents through the inverter to battery cable. Thesame cable that is carrying the amps is where the measurements are taken off.

2) Internal circuitry calibrated for ball park vs industrial grade measurement accuracy.

Even in a premium inverter like Victron who have voltage sense cables separate from battery cables, the voltage readings are still off relative to my BMV and Smart Battery reports whose data I independently confirmed with a Fluke meter.

In disgust at all this, I set my Victron BMV 700 as the 'Battery Monitor' for the entire system on my Venus GX. After a few weeks of observation, I decided it was better to use the Smart Lithium Battery itself as the single arbiter of voltage and current in the system so I set the GX to use PylonTech battery as battery monitor.

I have three Victron installations done in early March all using either Multiplus or Quattros and no GX device to control things - the absorb target voltage on all the inverters is set at 51.9v and in reality the voltage the inverter puts at the battery terminals is 52.4v!!!

All these installs are PylonTech which are extremely voltage sensitive, anything from 53.5v the BMS would go crazy on you.

I read on the Victron GITHuB that Victron wants to include voltage calibration in future firmware releases... I guess they are listening to field complaints

In short, trust the BMV 712 you have if properly calibrated. Victron went to great lengths to make a very accurate device.Take the Felicity's readings with a large pinch of salt.

Extras - Fangpusun CC amperage measurements - very accurate.

Fangpusun BMV clone measurements - inaccurate.

MustPower Type Inverters and products in general - voltage and amps very inaccurate.

ojeysky:
Folks I recently introduced BMV 712 to my setup(great tool by the way), but I noticed there is a 5A difference between what inverter display as charging current and what is actually seen by the BMV. Has anyone experienced this before?
Am suspecting it's probably wire+battery resistance but like to hear if anyone is getting actual figures on theirs (both sides)

NiyiOmoIyunade:
Internal calibration and measurement accuracy.

I find the Victron BMV to be pretty accurate and asian origin equipment to be very inaccurate when it comes to measurement.

Two things you are battling when measuring voltage or current from an inverter

1) Increased resistance and Voltage drop as you pass large currents through the inverter to battery cable. Thesame cable that is carrying the amps is where the measurements are taken off.

2) Internal circuitry calibrated for ball park vs industrial grade measurement accuracy.

Even in a premium inverter like Victron who have voltage sense cables separate from battery cables, the voltage readings are still off relative to my BMV and Smart Battery reports whose data I independently confirmed with a Fluke meter.

In disgust at all this, I set my Victron BMV 700 as the 'Battery Monitor' for the entire system on my Venus GX. After a few weeks of observation, I decided it was better to use the Smart Lithium Battery itself as the single arbiter of voltage and current in the system so I set the GX to use PylonTech battery as battery monitor.

I have three Victron installations done in early March all using either Multiplus or Quattros and no GX device to control things - the absorb target voltage on all the inverters is set at 51.9v and in reality the voltage the inverter puts at the battery terminals is 52.4v!!!

All these installs are PylonTech which are extremely voltage sensitive, anything from 53.5v the BMS would go crazy on you.

I read on the Victron GITHuB that Victron wants to include voltage calibration in future firmware releases... I guess they are listening to field complaints

In short, trust the BMV 712 you have if properly calibrated. Victron went to great lengths to make a very accurate device.Take the Felicity's readings with a large pinch of salt.

Extras - Fangpusun CC amperage measurements - very accurate.

Fangpusun BMV clone measurements - inaccurate.

MustPower Type Inverters and products in general - voltage and amps very inaccurate.

adrusa:


Check with a clamp meter to see who is telling the truth and use that to calibrate the BMV. Calibrate your inverter too if that is possible.

Thanks folks

180A is way way over what 35mm2 cable can take!

You should use a suitable pair of busbars please and then you can connect each battery directly to the busbar with 35mm2 or thicker cable vs having them in parallel with each other.

Since you have Lithium batteries, you want to be especially careful of overcurrent conditions. How smart is your BMS? In most Lithium I have used, the max amperage the battery will take reduces as you approach full charge e.g my 8 units of PylonTech US2000 can take 200A up to 51v or so - at 52v range, they instruct the GX to throttle the CCs current to 80A max.

It would be disastrous if I fed them 200A when they wanted 80A and this is the key role a GX plays in a large system - to be interfacer between a smart battery and the rest of the system.

All this preaching is because I understand that you want to feed your batteries 180A at 12v nominal and I seem to remember you have a basic BMS at best. Be sure your batteries can handle it safely under all conditions.

As your system gets larger, careful thought must go into system design, system stability and safety and it is not just enough to be adding more and more power into the batteries.

I have open loop Victron installs where a Quattro or Multi feeds a max 60A to a Lithium bank - I can do this without a Victron GX as interfacer because I am within the safe operating limits of the battery - if the client were to add one or two CCs to the installation as additional sources of current, then purchase of a GX device is mandatory else he will have to find another company to install for him. As much as within our power, we take no risks with customer installs.

ceaser:


Best option is to bite the bullet and going 35mm for the current set up.

But what happens if I decide to put a 3rd 60A MPPT SCC and maxing it out, thereby jacking up the SCC terminal to battery terminal current from 120A to 180A.

Is that a safe current to have around?
Is that safe for 35mm cable?

ceaser:


Best option is to bite the bullet and going 35mm for the current set up.

But what happens if I decide to put a 3rd 60A MPPT SCC and maxing it out, thereby jacking up the SCC terminal to battery terminal current from 120A to 180A.

Is that a safe current to have around?
Is that safe for 35mm cable?

Will that still be charging the same lithium bank ( Which is less than 200a)? Even though lithium na current guzzler I think 0.5C usually should be a limit you want to go, besides your battery BMS may also be a stopper.

Edit: Well addressed by @NiyiOmoIyunade guru himself

@ OjeySky, lovely graphics and monitoring up there, looks uncannily like EmonCMS but your signature web link is to PV output? I just set up a monitoring dashboard on EmonCMS very similar to yours but yours is far ahead in beauty.

I will connect with you directly - the Victron VRM reporting and dashboard portal has not impressed me with its graphics and visualizations.

THIS automatic transfer switch, any person has it in stock for sale?

CC Juo.

Malevonent:
THIS automatic transfer switch, any person has it in stock for sale?

NiyiOmoIyunade:
@ OjeySky, lovely graphics and monitoring up there, looks uncannily like EmonCMS but your signature web link is to PV output? I just set up a monitoring dashboard on EmonCMS very similar to yours but yours is far ahead in beauty.

I will connect with you directly - the Victron VRM reporting and dashboard portal has not impressed me with its graphics and visualizations.

Yes it's emoncms can be reached at https://prognathous-tropicbird-1681.dataplicity.io/emoncms/dashboard/view/oj-solar

ojeysky:


No idea, just got home to meet warning 32; Comms not interacting with the inverter

Th error message doesn't look that serious?

mank1234:


Th error message doesn't look that serious?

Literarily yes, but according to MPP once the Comms panel is unable to interact with the inverter, the inverter won't work. So waiting for Comms replacement boards.

ojeysky:


It's in my signature.... It's 2.25kw total

so with the recent fault developed by your mpp inverter, after barely 8months in service, would you still advice people to go for it?

earthrealm:


so with the recent fault developed by your mpp inverter, after barely 8months in service, would you still advice people to go for it?

Absolutely, if I had the option I will still go for it. I have a rough idea of what may have been the cause of the issue I had with the inverter but I don't want to state it as it's not what I know for a fact, also because it's not what can be easily re-created. That said, I think I may go for the MK especially if I have a 48v set-up but for now so long as I can get clear LOS to my panels and if it's a 24v set-up it's GK.

ojeysky:


Absolutely, if I had the option I will still go for it. I have a rough idea of what may have been the cause of the issue I had with the inverter but I don't want to state it as it's not what I know for a fact, also because it's not what can be easily re-created. That said, I think I may go for the MK especially if I have a 48v set-up but for now so long as I can get clear LOS to my panels and if it's a 24v set-up it's GK.

How about the MG variant? I notice many don't seem to talk about it.

n9jaboy:
Good morning,

Please I just bought 2No 150ah inverter batteries (auction). I'd love to charge it on both solar and NEPA. Which should be my best bet(hybrid inverter). My expected load is five 30watts Fan.

I will also like to know how many hours my fans will work. Thanks

Since you've made up your mind to use hybrid, your budget would determine which brand/product to go for, the marketers here can give you options.

I presume your batteries are used, hence, you can only know their capacity through service.

mctfopt:


How about the MG variant? I notice many don't seem to talk about it.

MG preceded the GK, the newer model has more features.

ojeysky:


MG preceded the GK, the newer model has more features.

Oh that makes sense.

BetaTechnicians:

Since you've made up your mind to use hybrid, your budget would determine which brand/product to go for, the marketers here can give you options.

I presume your batteries are used, hence, you can only know their capacity through service.

Thanks! Awaiting they response. Regards

Gurus diagram 1 and 2 which one is more accurate for 24v setup looking at the AH. thanks