Battery Monitors - Victron BMV-712 or AiLi Battery Monitor

[C&G in FL]

Originally Posted by gbaglo

The voltmeter does all I need it to do. I think you can have too much information, raising anxiety level.

Originally Posted by cpaharley2008

I installed a Trimetric battery monitor in one of my early trailers and like you say Glenn, too much information. Now I just use the plug in and the stock units in the trailer. Ignorance is bliss.....

I have to say I have the same inclinations as Glenn and Jim. I do have a plug in that displays battery voltage but I rarely plug it in. I generally do not do a lot of boondocking nor do I live in a cold climate. In the five years I have owned my Escape, I have only run the furnace all night once. I usually use a dual wattage quartz heater (900w/1500w) on the lower setting, even when temperatures approach freezing. Actually, if I cannot sit outside in a T-shirt, I don’t find the camping experience enjoyable. I have two primary methods of monitoring battery voltage. First, my GPS tracking device’s internal battery is kept charged by the trailer’s 12v system. If the GPS device senses a low DC current or total loss of DC current it sends me a text message indicating the condition, just as it does periodically when it detects the trailer is moving. The second method is to turn on a light. If it doesn’t come on and the battery cut off switch is on, I get a voltage reading from a volt meter or the plug in device. If the reading is low enough, I know it is time to replace the dual sixes. While batteries themselves are not subject to paying taxes, they are subject to the other inevitable........death at some point in time. And while I avoid actions that would result in excessive battery drain, I have more important things to concern me when on the road. Besides, a battery(ies) that appears to be healthy on Monday can suddenly die on Tuesday.

[rubicon327]

Originally Posted by rubicon327

No I think they are 8AWG. I was just showing a picture of the converter to emphasize how generous the lugs are on the 12V board. Should be able to accept 6AWG without an issue.

FWIW a newer 21 I worked on in late May 2019 does look like it has bigger wires....maybe 6AWG.

[ChuckBC]

Here is the layout for my new E19 raised dinette and you can see I added the Blue Seas switch and like Eggscape moved the converter. This is why I need to rewire and will be sorting out. I am wondering if I should have positive and negative from battery entering dinette box and connected to Blue Seas blocks. Then from these blocks I can go to thermal fuse (positive) and converter (negative). Original frame ground to this block. Does the solar (proposed) need to go to battery or would the connection to the 6AWG wired block work?

[tdf-texas]

Originally Posted by ChuckBC

Here is the layout for my new E19 raised dinette and you can see I added the Blue Seas switch and like Eggscape moved the converter. This is why I need to rewire and will be sorting out. I am wondering if I should have positive and negative from battery entering dinette box and connected to Blue Seas blocks. Then from these blocks I can go to thermal fuse (positive) and converter (negative). Original frame ground to this block. Does the solar (proposed) need to go to battery or would the connection to the 6AWG wired block work?

I have the Blue Seas switch as well - nice switch that should outlast the trailer.

The Blue Seas blocks sounds like a good idea - nice place to terminate the wiring. Just make sure that nothing could ever short across them. That is what the 60 amp Maxi fuse at the battery is for (melted wiring due to short) but you want to try to prevent shorting it.

No need to connect the solar controller to the battery direct - just make sure to connect it between the battery disconnect switch and the battery so it can charge while the trailer is in storage. The Blue Seas blocks would probably be a good place.

Don't forget that the solar controller output should be over current protected as well. Escape installs a 30 amp thermal fuse for their installations.
https://www.amazon.com/Bussmann-CBC-.../dp/B001PYQVMG

[ChuckBC]

For the solar controller is the thermal fuse mounted close to controller or close to my positive power block?

First pic I have posted to forum and if it was a smaller file would it appear landscape (not on side).

[tdf-texas]

Originally Posted by ChuckBC

For the solar controller is the thermal fuse mounted close to controller or close to my positive power block?

First pic I have posted to forum and if it was a smaller file would it appear landscape (not on side).

The 60 amp maxi fuse should be mounted close to the battery terminals so that a short in the battery wiring doesn't create a meltdown/fire - the current from a shorted battery can arc weld. Below is a pic of where the 60 amp fuse holder is installed on my trailer.

The output of a solar controller isn't going to present any such risk. The thermal fuse is there to protect the solar controller and can be put anywhere in the solar controller output loop that is convenient.

[ChuckBC]

Just wondering why the 60Amp MAXI fuse holder looks like lighter wire than your circuit wiring? Rubicon had shown a fuse holder with 6AWG. Am I missing something when I'm attempting to wire circuit from battery to converter with all 6AWG to ensure no resistance in current flow?

[tdf-texas]

Originally Posted by ChuckBC

Just wondering why the 60Amp MAXI fuse holder looks like lighter wire than your circuit wiring? Rubicon had shown a fuse holder with 6AWG. Am I missing something when I'm attempting to wire circuit from battery to converter with all 6AWG to ensure no resistance in current flow?

Pic is from original Escape installation and they used a 8 awg fuse holder and 8 awg battery wiring. I used that pic as it shows fuse holder location and I didn't have a more recent one. I replaced the wiring with 6 awg and the fuse holder with this.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

All this was done when I installed my solar system. At the same time, I separated the AC and DC wiring, upgraded the battery wiring, and replaced the 2 breakers with 4 breakers in the inverter breaker box so I could separate the microwave onto it's own breaker.

[Ronn]

Originally Posted by ChuckBC

Here is the layout for my new E19 raised dinette and you can see I added the Blue Seas switch and like Eggscape moved the converter. This is why I need to rewire and will be sorting out. I am wondering if I should have positive and negative from battery entering dinette box and connected to Blue Seas blocks. Then from these blocks I can go to thermal fuse (positive) and converter (negative). Original frame ground to this block. Does the solar (proposed) need to go to battery or would the connection to the 6AWG wired block work?

Hi Chuck, it looks as though you have mounted the Lagun into a non U-Shaped dinette.
There has been some interest in this forum regarding that mod. I don't believe that anyone has addressed doing this. You may want to address this in the Lagun thread for us. Thanks

ps. nice work by the way!!

[ChuckBC]

Will do on providing details on my raised dinette mod. The big credit needs to go to Ed with Eggscape. He blazed the way and I put my spin on some of the construction details.

To get image attachments right side up do I use a smaller file and pics I have not in landscape will work?

[gbaglo]

If you download your pictures into an editing app, you can rotate, rename and save and they will stay that way. That should strip the meta data that displays the photo in the proper orientation, no matter which way you hold your smart phone.

I send my pix to myself by email. I open them on my MacBook Air and save to the desktop.

[ChuckBC]

Originally Posted by tdf-texas

I have the Blue Seas switch as well - nice switch that should outlast the trailer.

The Blue Seas blocks sounds like a good idea - nice place to terminate the wiring. Just make sure that nothing could ever short across them. That is what the 60 amp Maxi fuse at the battery is for (melted wiring due to short) but you want to try to prevent shorting it.

No need to connect the solar controller to the battery direct - just make sure to connect it between the battery disconnect switch and the battery so it can charge while the trailer is in storage. The Blue Seas blocks would probably be a good place.

Don't forget that the solar controller output should be over current protected as well. Escape installs a 30 amp thermal fuse for their installations.
https://www.amazon.com/Bussmann-CBC-.../dp/B001PYQVMG

An addition to my electrical upgrade is to have at dinette box a pure sine wave inverter for charging cel phones, computer, USB cycling lights only. I note the small 250W inverters are typically cigarette plug ins. I thought I would power with added fuse through my new Blue Seas 6 AWG wired power terminals in dinette bench. Input on inverters and plan always appreciated.

[Vermilye]

Originally Posted by yangstyle

I have the escape installed solar and inverter with go power remote.
If I were to install this Aili meter would I be able to leave in the go power remote so I could use it to turn on and off the inverter as I can now?
It is handy to not have to lift up the dinette seat to turn the inverter on and off.

If you are asking about replacing the remote button on the GoPower Solar Controller, you can add a GoPower GP-SWR-A remote for around $25.00. If you already have the remote, it will still work after adding the shunt for the meter. If you use the inverter to power the microwave, you might order the larger 350 amp shunt - the stock 100 amp might be cutting it close for the microwave.

[yangstyle]

Originally Posted by Vermilye

If you are asking about replacing the remote button on the GoPower Solar Controller, you can add a GoPower GP-SWR-A remote for around $25.00. If you already have the remote, it will still work after adding the shunt for the meter. If you use the inverter to power the microwave, you might order the larger 350 amp shunt - the stock 100 amp might be cutting it close for the microwave.

Thanks Jon,
My mistake, I meant the controller. I called it the remote for some reason. I use it to turn on the inverter. Good to know about the 350 amp shunt.
I might try the AiLi as it sounds more accurate than the Go Power though I was hoping I could leave the controller in place even if I use it just to turn the inverter off and on.

[Vermilye]

Originally Posted by yangstyle

Thanks Jon,
My mistake, I meant the controller. I called it the remote for some reason. I use it to turn on the inverter. Good to know about the 350 amp shunt.
I might try the AiLi as it sounds more accurate than the Go Power though I was hoping I could leave the controller in place even if I use it just to turn the inverter off and on.

The GoPower controller & the Aili monitor do different things and do not depend on or interfere with each other. If you have solar, you are going to still need the GoPower controller. I'd still add the GoPower remote so I don't have to stand on my head to turn on & off the inverter. I placed mine over the refrigerator.

[MyronL]

Began reading this thread on battery monitors and thinking maybe I should get one. I have the two 6 volt batteries and 200 watts of solar power, and we rarely use shore power when we camp.

Monitors are very practical, though they seem to be a bit pricey. I should get one. Then my brain freeze thawed out. Some years back when I invested in solar I chose the SunSaverDuo solar controller made by Morningstar. It’s in the tongue box a foot from my batteries.

I have the SSD-25RM, $154 with the optional Remote Meter. Now I don’t even think about it. A wire from the controller runs to the remote, kept up on a shelf inside the trailer. Its LED buttons tell me the battery voltage status, solar input, it has a temperature sensor, and probably other stuff I also forgot about.

[John in Santa Cruz]

Originally Posted by MyronL

Began reading this thread on battery monitors and thinking maybe I should get one. I have the two 6 volt batteries and 200 watts of solar power, and we rarely use shore power when we camp.

Monitors are very practical, though they seem to be a bit pricey. I should get one. Then my brain freeze thawed out. Some years back when I invested in solar I chose the SunSaverDuo solar controller made by Morningstar. It’s in the tongue box a foot from my batteries.

I have the SSD-25RM, $154 with the optional Remote Meter. Now I don’t even think about it. A wire from the controller runs to the remote, kept up on a shelf inside the trailer. Its LED buttons tell me the battery voltage status, solar input, it has a temperature sensor, and probably other stuff I also forgot about.

thats a solar charge controller, but it doesn't know anything about nonsolar charging (like, your power center when plugged in) or load current.

[Vermilye]

It might be worth pointing out the differences between a solar controller & a battery monitor.

The prime function of a solar controller it to control the current between the solar panels & the batteries. Most provide multiple stages, i.e., Bulk where it puts as much current into the batteries as the panels produce, Absorption where the controller limits the voltage in order to reduce the current so that the batteries don't "off gas" for the last 20% of the charging cycle, and finally Float, reducing the voltage to the point where the batteries accept little if any current, but provide for the loads in the trailer. Incidentally, the absorption stage will take hours to finish off the last 20% of charging. Most controllers indicate a full battery well before it is really full.

The solar controller has no way of knowing how much current the batteries are producing other than measuring the voltage, since the battery loads do not pass through the controller. The "% full" is an approximate. The battery voltage shown on the controller display is not accurate unless the sun is down or the panels are disconnected because it is measuring the bulk/absorption/float voltage, or, if the converter is connected to a pedestal, its output.

A battery monitor is a separate device from a solar controller. Most require a shunt placed between the negative pole of the battery and ALL loads. The shunt is a low value resistor that drops a small amount of voltage (ohm's law) that the controller electronics use to determine the amount of current. Positive voltage = current going into the battery, negative voltage = current coming out. The electronics keeps track of the in & out current. Combined with time, the result is amp hours, an excellent determination of battery capacity. A number of parameters need to be set when configuring the battery monitor, but once properly configured, you can check the number of amp hours used or available at any time. The voltage measurement shown on the battery monitor is just as inaccurate a depiction of the battery state of charge as the solar controller when the converter or solar controller is providing voltage, so using amp hours to determine the state of charge is more accurate.

Do you need a battery monitor? Only if you want to know the exact state of charge of your batteries at any time. That tends to be dry campers that use lots of amp hours. For most, a voltage measurement (done under the correct conditions) is all you need.

[MyronL]

Thank you for that, Jon, and John. Think I get it. Since my amp usage is minimal, thinking for me all I really need to know is the tipping point...like if my batteries' storage levels are in danger of falling below 11 volts.

[John in Santa Cruz]

going purely by voltage is tricky. under load, the voltages read low, under charge conditions, they of course read high. you can only rely on the voltage reading when the battery has been resting at least 30 minutes with no charge OR load, or at most very minimal loads like LED lighting. and then the nominal voltages are temperature dependent, most tables are given at 68F ...

11V is really really low, like totally flat, into the damaged battery zone. 12.6V is a fully charged battery at rest, 12.1V is 50% discharged which is the limit of safe discharge for long battery life. of course, if you are pulling a heavy load off the battery, like running a AC inverter and a high wattage appliance, the voltage reading will be much lower than the charge state

a proper monitor with a shunt like the Trimetric or whatever, it actually tracks the amp*hours coming out of the battery so it can give a meaning answer regardless of the load, ditto it tracks the amp*hours being put back into the battery, whether from solar, a power converter, or the tow vehicle charging via the 7-blade.