Charge level and settings

[jacr]

If you dont have them get yourself a Kilowatt meter and a AC/DC mutlimeter/clamp meter. For reference I looked on Amazon Canada, Killowatt meter $20 and DC Clamp Meter $50. You an get them as most hardware stores or automotive stores for the DC meter. Both are inexpensive and whilst they dont have calibrated accuracy can get you good data quickly. If your not sure what to get I can post some links.

We have a Kilowatt meter (somewhere!!). I have no idea how to select a Clamp Meter. On Amazon there is everything from brands I've never heard of up to very expensive Flukes. Can you make some suggestions?

Thanks again

[Bala]

For the clamp meter you are just looking for one that has DC, which most now do. Mine is a few years old and has two ranges for DC Amps but most are now auto ranging. I paid about $60 Aud from an electronics chain store, it does not even have a brand on it. When in 0-40A range it will read around 1 Amp with out being connected so they are not calibrated but for getting a close figure on what is going on they are great.
Turn your panels off and clamp over the battery cable and you will see what your current draw is. Inverter etc off and you will see what your panels are putting in. Use W V A calculators and you can get an idea of Ah being used.

This is the cheapest I found after a quick look.

https://www.amazon.ca/dp/B082B134ZQ/ref=syn_sd_onsite_desktop_15?uh_it=45dba5e9f274aab70ad5ae1b72285821_CT&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyTjFIWElNTlVNQks2JmVuY3J5cHRlZElkPUEwMzE2MDY3M0lMQVU0V0RXRjhMJmVuY3J5cHRlZEFkSWQ9QTA3NDkyMjExTlpKMlk2VFo2OUZTJndpZGdldE5hbWU9c2Rfb25zaXRlX2Rlc2t0b3AmYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl&th=1

They go up in price from there . Essentially they are mostly just imported rubbish or good value for the purpose, it is just what type of buyer you are.

I have had a lot of cheap multi meters over the years for automotive and they can get damaged easily so I am happy buying cheap for the workshop and field work. Electricians in the workshop had calibrated fluke meters. If you want to balance cells of Lithium then I would be looking at fluke and getting it calibrated.

[SunEagle]

For the clamp meter you are just looking for one that has DC, which most now do. Mine is a few years old and has two ranges for DC Amps but most are now auto ranging. I paid about $60 Aud from an electronics chain store, it does not even have a brand on it. When in 0-40A range it will read around 1 Amp with out being connected so they are not calibrated but for getting a close figure on what is going on they are great.
Turn your panels off and clamp over the battery cable and you will see what your current draw is. Inverter etc off and you will see what your panels are putting in. Use W V A calculators and you can get an idea of Ah being used.

This is the cheapest I found after a quick look.

https://www.amazon.ca/dp/B082B134ZQ/ref=syn_sd_onsite_desktop_15?uh_it=45dba5e9f274aab70ad5ae1b72285821_CT&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyTjFIWElNTlVNQks2JmVuY3J5cHRlZElkPUEwMzE2MDY3M0lMQVU0V0RXRjhMJmVuY3J5cHRlZEFkSWQ9QTA3NDkyMjExTlpKMlk2VFo2OUZTJndpZGdldE5hbWU9c2Rfb25zaXRlX2Rlc2t0b3AmYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl&th=1

They go up in price from there . Essentially they are mostly just imported rubbish or good value for the purpose, it is just what type of buyer you are.

I have had a lot of cheap multi meters over the years for automotive and they can get damaged easily so I am happy buying cheap for the workshop and field work. Electricians in the workshop had calibrated fluke meters. If you want to balance cells of Lithium then I would be looking at fluke and getting it calibrated.

Please be careful. "cheap" can be dangerous when you are talking about electrical measuring devices.

Just make sure it has both an amp rating high enough for what you are going to measure and a CAT III insulation rating

[Bala]

Please be careful. "cheap" can be dangerous when you are talking about electrical measuring devices.

Just make sure it has both an amp rating high enough for what you are going to measure and a CAT III insulation rating

Nice info, I cant see Cat111 listed in the specs of the one I linked above, but in this one CE and Cat111 are listed.

https://www.amazon.ca/Bluetooth-Resistance-Capacitance-Temperature-Frequency/dp/B08BZCHSJR/ref=sr_1_1_sspa?crid=3S8M9LOLFD3ON&dchild=1&keywords=dc+clamp+on+meter&qid=1609371921&sprefix=dc+clam%2Ckitchen%2C427&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzQ0ZHQ0U3WExSTENZJmVuY3J5cHRlZElkPUEwNDIzMTE2MzFRTjE5TUhDMURBMSZlbmNyeXB0ZWRBZElkPUEwNjcwMDcxMlFVWlBPTDBLUVpITyZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

With cheap imports it is easy enough to put CE and Cat111 on a unit so who knows if they are actually getting certified but better to have one with those things on it.

[SunEagle]

Nice info, I cant see Cat111 listed in the specs of the one I linked above, but in this one CE and Cat111 are listed.

https://www.amazon.ca/Bluetooth-Resistance-Capacitance-Temperature-Frequency/dp/B08BZCHSJR/ref=sr_1_1_sspa?crid=3S8M9LOLFD3ON&dchild=1&keywords=dc+clamp+on+meter&qid=1609371921&sprefix=dc+clam%2Ckitchen%2C427&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzQ0ZHQ0U3WExSTENZJmVuY3J5cHRlZElkPUEwNDIzMTE2MzFRTjE5TUhDMURBMSZlbmNyeXB0ZWRBZElkPUEwNjcwMDcxMlFVWlBPTDBLUVpITyZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

With cheap imports it is easy enough to put CE and Cat111 on a unit so who knows if they are actually getting certified but better to have one with those things on it.

I guess there is really no way to know the rating of an off shore device. Maybe investing in a pair of electric gloves rated for 600volts is another way to make sure you are being safe.

[jacr]

I found the kilowatt meter and plugged the fridge into it for 24h. Over that period it said that it used about 1kWh with a peak of 130W. To my naive mind, that doesn't seem too bad.
I haven't bought a clamp meter yet - some items on Amazon don't ship to our location.

[chrisski]

I found the kilowatt meter and plugged the fridge into it for 24h. Over that period it said that it used about 1kWh with a peak of 130W. To my naive mind, that doesn't seem too bad.
I haven't bought a clamp meter yet - some items on Amazon don't ship to our location.

That amount of energy is about a half of one of your battery's worth of storage for a day when that battery is brand new at 100%. For my FLA batteries, that is an entire battery since I don't wnat them to be below 50%. If you're saving for two days of power, you need two of your eight batteries to power the fridge. Until this equalization is done and the batteries are as healthy as they can get, its probably more.

That is fine, if that's what you want. It's your plan. I'm not here to criticize your plan. I only have a 12 volt system I take out a couple of times a month to go boondocking.

With mine, I was surprised to find out that 80%-90% of my draw came not from my inverter, but what was already wired in my RV for 12 volts. I was also shocked to find about 3/4 of this DC draw or more came from the blower fan for my propane heater.

I have a battery monitoring system, but a clamp meter can be used to find the same thing. May be after you get this clamp meter attached, if you're using this to measure DC power, you'll find something like that. I found a couple of 12 volt DC bulbs that had not been swapped from incandescent to LED. After I swapped those, I went from a 3 amp draw to about .5 amps. I also found that I was not shutting a DC entertainment system off, which had cost me 5 amps an hour. I also found leaving the outside lights on overnight was 1.5 amps an hour. I found my inverter was using 1 amp an hour when not in use, just as the specs say. Shutting the entertainment system off when not in use, the inverter off when not in use. By shutting that off, I can save about 1/4 what I use a night.

[Bala]

I found the kilowatt meter and plugged the fridge into it for 24h. Over that period it said that it used about 1kWh with a peak of 130W. To my naive mind, that doesn't seem too bad.
I haven't bought a clamp meter yet - some items on Amazon don't ship to our location.

Fridge power use has a few variables. Ambient temp, how often it is open and what is put in it. I factor in 1 kwh a day for a fridge but ours do use less and I live in the tropics. As I dont know the variables for you I cant say if it is ok or not, but it does seem a bit high for a cold climate.

As a side not I believe when shopping for electrical items of off grid, especially that will be on for long periods, that you should shop on energy use, not price. Which usually means you are buying the latest model and the most expensive.

Run everything else you can on the Kilowatt meter and add it all up. Your inverter is listed at 25w continuous minimum so add that and run all the data through a calculator to come up with a daily amp hr figure. Look at what your solar is putting in to see where your in / out stands. Also look at the data sheet for you batteries, there is a chart for capacity at temp, the colder it is the less capacity you have.

You really need to understand how much power you are using and when, how much you get from the sun on a given day and what you battery bank can supply given those factors.

If you work hard at working all that out it will make your life much easier. I have sealed batteries now so cant check sg but even when I had FLA I didnt need to check sg to know where my SOC was at. I just look at the V meter on my wall inside the house and knowing what the weather was like for previous days, and what it will be like the next day, I can tell if solar is going to support my energy use or if a generator run is needed.

[J.P.M.]

Fridge power use has a few variables. Ambient temp, how often it is open and what is put in it. I factor in 1 kwh a day for a fridge but ours do use less and I live in the tropics. As I dont know the variables for you I cant say if it is ok or not, but it does seem a bit high for a cold climate.

As a side not I believe when shopping for electrical items of off grid, especially that will be on for long periods, that you should shop on energy use, not price. Which usually means you are buying the latest model and the most expensive.

Run everything else you can on the Kilowatt meter and add it all up. Your inverter is listed at 25w continuous minimum so add that and run all the data through a calculator to come up with a daily amp hr figure. Look at what your solar is putting in to see where your in / out stands. Also look at the data sheet for you batteries, there is a chart for capacity at temp, the colder it is the less capacity you have.

You really need to understand how much power you are using and when, how much you get from the sun on a given day and what you battery bank can supply given those factors.

If you work hard at working all that out it will make your life much easier. I have sealed batteries now so cant check sg but even when I had FLA I didnt need to check sg to know where my SOC was at. I just look at the V meter on my wall inside the house and knowing what the weather was like for previous days, and what it will be like the next day, I can tell if solar is going to support my energy use or if a generator run is needed.

FWIW, I've got a decent full size side/side fridge in an unconditioned garage that's used only when I'm loaded with house guests/friends, more winter refugees from Buffalo than in the summer. Anyway, a kill-a-watt meter shows it draws ~ 104 running watts. Winter 24 hr. usage is ~ 1.0 kWh/24 hrs. Winter garage temp. is ~ 55-65 F. Summer daily usage is ~ 1.3 kWh/24 hrs. The ave. summer garage temp. is probably 75-85 F.

[chrisski]

FWIW, I've got a decent full size side/side fridge in an unconditioned garage that's used only when I'm loaded with house guests/friends, more winter refugees from Buffalo than in the summer. Anyway, a kill-a-watt meter shows it draws ~ 104 running watts. Winter 24 hr. usage is ~ 1.0 kWh/24 hrs. Winter garage temp. is ~ 55-65 F. Summer daily usage is ~ 1.3 kWh/24 hrs. The ave. summer garage temp. is probably 75-85 F.

My small propane fridge on electric mode runs 330 watts from the inverter, so could be 370 watts from the batteries accounting for inverter inefficiencies. It can also be on up to 8 hours to get cold when first turned on for a trip.

[Mike90250]

Many propane fridges, don't have a compressor, they simply have a heater element to emulate the propane flame !!

[jacr]

My small propane fridge on electric mode runs 330 watts from the inverter, so could be 370 watts from the batteries accounting for inverter inefficiencies. It can also be on up to 8 hours to get cold when first turned on for a trip.

I’m surprised that a 2-way fridge on electric mode is less efficient than a regular electric fridge. Is that right? In that case maybe I won’t try and fix our 2-way fridge.

[Bala]

As Mike said two and three way fridges will have an element to heat. My caravan fridge draws 16A 12vdc. I will be swapping it out for a Bushman 130l compressor fridge and run lithium batteries.

I also have a 40l Engel compressor fridge for camping.