Simple electrical system, inverter and monitor suggestions

[HazMatt]

Originally Posted by PNW_Steve

When I go out to the trailer I will take a look.... CRS...

It was recommended by one of the mods over on Forums - Solar Panels - Solar Panels Forum

Lots of good solar and battery info over there.

iDoble gracias, senor!

[kazetsukai]

Originally Posted by inhof009

I found a cheap monitor on Amazon here:
https://www.amazon.com/gp/aw/d/B07KP...?ie=UTF8&psc=1
That looks like it'll work to monitor amp usage, but sometimes Amazon products that are cheap tend to be too good to be true.

Any suggestions on products for an inverter/converter and monitor?

I've bought like 4 or 5 of those monitors. I've had a couple go bad throughout the years, but they're great. It will show current Voltage, draw in both Amps and Watts, and record energy moved across the bar in Wh, which you can reset.

I currently have two of them installed in my bus, one for solar input, the other for electric consumption. I typically reset them at the same time to see whether my solar is keeping up with my test loads.

[HazMatt]

A 40 to 50% mortality rate don't sound great to me!
It's one thing if they perform the nifty tricks, but w/o reliable longevity, it is probably much cheaper in the long run to not buy the cheaper units that'll flame out and crash in shorter order...

Originally Posted by kazetsukai

I've bought like 4 or 5 of those monitors. I've had a couple go bad throughout the years, but they're great. It will show current Voltage, draw in both Amps and Watts, and record energy moved across the bar in Wh, which you can reset.

I currently have two of them installed in my bus, one for solar input, the other for electric consumption. I typically reset them at the same time to see whether my solar is keeping up with my test loads.


Attachment 34282

[kazetsukai]

Originally Posted by haz.matt.1960

A 40 to 50% mortality rate don't sound great to me!

The units that died spent most of their time outdoors in a humid (and eventually frozen) environment. This was back when the solar I have on my bus today was in use to power pumps for an aquaponic greenhouse. I was learning, and probably wired them incorrectly a few times.


I have a bunch of them- most in boxes of electrical stuff that I hook up from time to time to test batteries and loads.

[HazMatt]

Fair 'nuff!

Originally Posted by kazetsukai

The units that died spent most of their time outdoors in a humid (and eventually frozen) environment. This was back when the solar I have on my bus today was in use to power pumps for an aquaponic greenhouse. I was learning, and probably wired them incorrectly a few times.


I have a bunch of them- most in boxes of electrical stuff that I hook up from time to time to test batteries and loads.

Failure to adhere to mfg's SOPs is a different fettle of kish...
NH winters aren't particulary easy on people, let alone sensitive electronics...

[joeblack5]

Steve,... but that is kind of the real problem.... If you do not know how good your battery is and or you have lost electrolyte how are you determining in what shape the battery is.




For example you can make any old worn out empty battery look good on the SG if you fill up with acid. So for the average guy who buys those it would look like the batteries are new and fully charged.


What additional parameters brings the SG measurement in line with the real capacity of the battery?
It seems that the SG is only really useful if you have the whole maintenance history of the battery.


Thnaks J

[PNW_Steve]

Never mind......

[joeblack5]

OK, no problem I know it gets hard when questions get really technical.


Kazetsukai, I have a similar unit in LED version on our 48 Volt forklift. It counts the Ah up and down and Amp pos and neg. You are using one for solar and usage .. does that mean these are measuring only one way?


inhof009.
We used a trimetric in an earlier conversion, now a xantrex.


They are very handy on day to day base. Unfortunately lead acid are a lot more difficult to use then lion. That is because lead acid is very inefficient charge / discharge cycle. If you took 20 Ah out and your solar charges 20 Ah back in then for lead acid you are about 20% short.
so 20 Ah out needs to be corrected with 24 AH in... This does not matter that much if you completely charge the battery often so that you know that the battery is charged to the maximum.
For solar, as we are in our case, that is unfortunate because charging a lead acid battery completely is basically accomplished by overcharging the battery and venting some of the excess charge in gassing a little water of and in heat. Mostly the lead acid battery also get pretty warm.

The trimetric / xantrex and such can compensate for the above. They mainly measure the time a battery is held above a certain voltage , and then define that the battery is charged to the max.


The way Kazetsukai is using two devices for in and out is a really neat solution because you get a better feel for the "unaccounted losses"


I ran a couple of electric cars with lead acid and unless new they are a real pain to deal with. Converted to LIon and much better.


The definition of charge / SG / voltages / capacity are very poorly defined and based on wasting energy similar to an overflowing bucket for a certain amount of time and then determining the fullness of the bucket from the size of the puddle around the bucket...... BUT lead acid is cheap and so is electricity.


By the way, what size batteries do you have for starting batteries?


Johan

[PNW_Steve]

Originally Posted by joeblack5

OK, no problem I know it gets hard when questions get really technical.


Kazetsukai, I have a similar unit in LED version on our 48 Volt forklift. It counts the Ah up and down and Amp pos and neg. You are using one for solar and usage .. does that mean these are measuring only one way?


inhof009.
We used a trimetric in an earlier conversion, now a xantrex.


They are very handy on day to day base. Unfortunately lead acid are a lot more difficult to use then lion. That is because lead acid is very inefficient charge / discharge cycle. If you took 20 Ah out and your solar charges 20 Ah back in then for lead acid you are about 20% short.
so 20 Ah out needs to be corrected with 24 AH in... This does not matter that much if you completely charge the battery often so that you know that the battery is charged to the maximum.
For solar, as we are in our case, that is unfortunate because charging a lead acid battery completely is basically accomplished by overcharging the battery and venting some of the excess charge in gassing a little water of and in heat. Mostly the lead acid battery also get pretty warm.

The trimetric / xantrex and such can compensate for the above. They mainly measure the time a battery is held above a certain voltage , and then define that the battery is charged to the max.


The way Kazetsukai is using two devices for in and out is a really neat solution because you get a better feel for the "unaccounted losses"


I ran a couple of electric cars with lead acid and unless new they are a real pain to deal with. Converted to LIon and much better.


The definition of charge / SG / voltages / capacity are very poorly defined and based on wasting energy similar to an overflowing bucket for a certain amount of time and then determining the fullness of the bucket from the size of the puddle around the bucket...... BUT lead acid is cheap and so is electricity.


By the way, what size batteries do you have for starting batteries?


Johan

No not technical.

Just having trouble composing a civil response and unwilling to argue.

[kazetsukai]

Originally Posted by joeblack5

Kazetsukai, I have a similar unit in LED version on our 48 Volt forklift. It counts the Ah up and down and Amp pos and neg. You are using one for solar and usage .. does that mean these are measuring only one way?

Yeah, they will not measure reverse flow. I bridge two bus bars (negative) with the load measuring shunt so I can put all the batteries and solar charge controller upstream of it (the solar negative in its measuring shunt), and effectively measure all loads.

While it would be neat if they did measure reverse flow, I don't see much use for this outside of idk, an inverter/charge combo. My inverter has a charger, but I don't use it because I don't think I can get it to respect my desired voltage range with this battery.


I've been charging the battery up to 23.5V, I'm bumping that up to 24.5V today. The seller recommends a max of 24.9V, (4.15v per cell, 0.05v per cell lower than their rated 4.20v) probably to keep buyers in the safe zone. I'll probably be getting another one of these in two weeks so I can test my inverter at near max loads, and run constant 300w-400w loads through the night.

Originally Posted by joeblack5

The way Kazetsukai is using two devices for in and out is a really neat solution because you get a better feel for the "unaccounted losses"

Yeah, I think two units provide a better idea of whats going on, but I'm a little confused by some of my findings, to be honest. Once I fully charge the batteries, the charge controller floats even in the presence of load. When the voltage dips, the controller goes back into absorption/bulk. I'd expect the solar input to closely match loads, but when I'm pulling 250W and the batteries are fully charged, the solar input is somewhere around 50W. The meters always show a 100w-500w surplus over load during the daytime this way, so effectively the solar is covering it. Once I have another battery all balanced and setup, I'll try continuous 1kw+ to see what happens.

[joeblack5]

Originally Posted by PNW_Steve

No not technical.

Just having trouble composing a civil response and unwilling to argue.

Sorry that I somewhere seem to have offended you, certainly was not my intention.
Just was trying to learn other experienced peoples approach to the relation ship of SG voltage and SOC.




Johan