Battery Questions

[rando]

The voltage readings on the ZAMP are of some use, if you know what the load/charge current on your battery is when you read the voltage. If you have little to no current flowing into or out of your batteries you can use a voltage to SOC table to guestimate the SOC:

The lights on the FWC monitor panel are useless. A decent battery monitor is worth the investment.

 

[PaulT]

*2 on the camper battery lights.

On the Zamp display, while the voltage displayed is the voltage on the battery, it may be showing the voltage supplied by the alternator, or the voltage supplied by the Iota converter, or the voltage supplied by the Zamp if solar charging is happening. Or, lastly, it may be showing the battery voltage that the battery is supplying to whatever load it has.

The voltage table in rando’s post expects the battery to be a resting voltage. The resting voltage is accurate several hours after all loads have been removed and charging has stopped from all charging sources.

Practically, this means sometime after dark and if the fridge hasn’t run for a long time.

This is why you’re getting so many recommendations to get a battery monitor that measures charging and usage with a shunt to know current flow over time.

Hang in there & keep asking good questions. It all becomes clearer after a while. This stuff is easy. Knowing all the bones & what they do is hard. Not to mention why you shouldn’t eat grapefruit with some medications or why you should not drink milk with your tetracycline.
Paul

 

[doc]

*2 on the camper battery lights.

On the Zamp display, while the voltage displayed is the voltage on the battery, it may be showing the voltage supplied by the alternator, or the voltage supplied by the Iota converter, or the voltage supplied by the Zamp if solar charging is happening. Or, lastly, it may be showing the battery voltage that the battery is supplying to whatever load it has.

The voltage table in rando’s post expects the battery to be a resting voltage. The resting voltage is accurate several hours after all loads have been removed and charging has stopped from all charging sources.

Practically, this means sometime after dark and if the fridge hasn’t run for a long time.

This is why you’re getting so many recommendations to get a battery monitor that measures charging and usage with a shunt to know current flow over time.

Hang in there & keep asking good questions. It all becomes clearer after a while. This stuff is easy. Knowing all the bones & what they do is hard. Not to mention why you shouldn’t eat grapefruit with some medications or why you should not drink milk with your tetracycline.
Paul

The voltage readings on the ZAMP are of some use, if you know what the load/charge current on your battery is when you read the voltage. If you have little to no current flowing into or out of your batteries you can use a voltage to SOC table to guestimate the SOC:

The lights on the FWC monitor panel are useless. A decent battery monitor is worth the investment.

Yes! It is actually a very interesting topic. I too now see the value of investing in a battery monitor, which I will be doing soon. Why does FWC even install the push button battery monitor if it is not of any use? There must be some logic there...

 

[rando]

I have no idea why they install their monitor panel - the battery monitoring is useless and the tank monitoring is only of marginal value. Having pulled and upgraded the monitor panel on my Fleet, the electronics in the original appear to be circa 1995 so I am guessing it is just tradition that they still use it. Given the constant year/year price increases on FWC, the monitor panel should have been updated to something like this years ago:
https://www.simarine.net/

 

[knoxswift]

https://www.simarine.net/

OH! I like that....

 

[longhorn1]

What battery monitor is recommended? I have a 2014 Grandby, 2 AGM batteries and 100W solar. The solar system and controller are Zamp, as well as my 80W portable (no controller on portable). I'm on my 5th camping season, with no issues with the batteries. I try not to let the Zamp controller show less than 12.2, 12.1 at the lowest. We have the Dometic 80L compressor fridge, I use a CPAP machine. We are careful with the use of the lights and furnace. I have managed to get by, but I wonder if I would have better piece of mind with a monitor. It might keep me from worrying as allowing me to use more lights and furnace without worry. I'm not electrically inclined, so I wouldn't have a clue as how to install and even with good instructions would not be comfortable. I would probably take it somewhere to get installed. Can someone explain in easy to understand language what the monitor shows. Thanks, jd

 

[rando]

The BMV-712 is the latest and greatest in monitors:

https://www.victronenergy.com/panel-systems-remote-monitoring/bmv-712-smart

Electrically it is very easy to install (buy a short heavy battery cable, disconnect the cable from negative terminal from your batteries, connect this to the load terminal on the provided shunt, connect the battery cable between the other side of the shunt and the battery, connect the positive wire to the positive terminal of your battery) the hardest part is using a hole saw to cut a hole in your cabinet for the display. Any RV/Marine 'mechanic' could install it in less than an hour.

 

[ckent323]

longhorn et al,

Are your batteries true deep cycle? If you are regularly drawing your batteries down below 70% of full charge then I recommend using true deep cycle batteries over starting or hybrid Marine batteries.

I am reading that several folks are using Exide batteries. I am not real familiar with Excide but the only so called deep cycle batteries I have seen that are made by Exide are Marine Deep Cycle which are actually hybrid batteries. They are not the same as a true deep cycle which has thick plates of 0.10" or greater and thick grids of 0.095" or greater.

A marine battery typically falls between a starting and deep cycle battery, although some marine batteries are true deep cycle batteries. Often, the labels "marine" and "deep cycle" are used interchangeably or together, which causes some confusion.

True deep cycle batteries are made by Crown, Deka, Lifeline, Rolls-Surrette, and Trojan. There are probably some others

For links to a lot of info on batteries see:

http://www.wanderthewest.com/forum/topic/15574-ultimate-battery-thread/


Regards,
Craig

 

[Wallowa]

The voltage readings on the ZAMP are of some use, if you know what the load/charge current on your battery is when you read the voltage. If you have little to no current flowing into or out of your batteries you can use a voltage to SOC table to guestimate the SOC:

The lights on the FWC monitor panel are useless. A decent battery monitor is worth the investment.

Hmmmm..plugged into 110v while stored in shop...IOTA Q4...twin FWC AGM 12v batteries and Zamp meter shows a steady 13.6...how does this square with this chart? ['16 Hawk].

Thanks..Phil

 

[smlobx]

Phil I believe that your battery state needs to be measured when the batteries are " at rest". By that I mean without any charging device for at least a couple of hours. I measure mine the next day...

 

[coloradoclimber97]

The BMV-712 is the latest and greatest in monitors:
the hardest part is using a hole saw to cut a hole in your cabinet for the display.

Hey rando, the BMV-712 is a Bluetooth enable device, why cut any hole in your cabinet? Am I missing something?

 

[Wallowa]

Phil I believe that your battery state needs to be measured when the batteries are " at rest". By that I mean without any charging device for at least a couple of hours. I measure mine the next day...

Thanks I missed that...SOC..means a battery without load, in or out....wonder what the "13.6v" I see on Zamp monitor means when on 110v?

Thanks again for your input.

Phil

 

[rando]

Wallowa, on 26 Jul 2018 - 6:26 PM, said:

Thanks I missed that...SOC..means a battery without load, in or out....wonder what the "13.6v" I see on Zamp monitor means when on 110v?

Thanks again for your input.

Phil

It means the IOTA thinks your battery is fully charged and has switched to float charge.

 

[rando]

Hey rando, the BMV-712 is a Bluetooth enable device, why cut any hole in your cabinet? Am I missing something?

For me anyway, I often don't have my phone or don't want to have to find it, so it is nice to be able to glance at the monitor to be able to see what is going on. You should mount the display unit somewhere, so you may as well put it somewhere you can see it. The phone gives much more detail, but the display gives instant feedback.

 

[radarcontact]

Thanks I missed that...SOC..means a battery without load, in or out....wonder what the "13.6v" I see on Zamp monitor means when on 110v?

Thanks again for your input.

Phil

Rando answered your question, but I'm curious....when you're not on 110V and charging from your solar panel, does your Zamp ever show the same approximate float voltage (~13.6V)?

 

[Wallowa]

Rando answered your question, but I'm curious....when you're not on 110V and charging from your solar panel, does your Zamp ever show the same approximate float voltage (~13.6V)?

Good question...I believe it does, but my old memory is fuzzy on that..

What I gather is that yes a better monitor will give real time accurate system evaluations but the issue, if indeed I face this issue, is that the controller doesn't "know when to quit" and may over-charge the batteries [two 12v in my case]...

I will roll the beast out into the sun tomorrow and report back on whether or not I still get the "13.6" floating charge indication on solar power alone.

Phil

 

[GDinMT]

I have a Victron BVM-712 that I’ll be installing before our next trip. Is there anything that needs to be done to “unhook” the OEM push button battery level indicator?

 

[rando]

Nope, you can leave it connected, it won't affect the Victron.

 

[longhorn1]

longhorn et al,

Are your batteries true deep cycle? If you are regularly drawing your batteries down below 70% of full charge then I recommend using true deep cycle batteries over starting or hybrid Marine batteries.

I am reading that several folks are using Exide batteries. I am not real familiar with Excide but the only so called deep cycle batteries I have seen that are made by Exide are Marine Deep Cycle which are actually hybrid batteries. They are not the same as a true deep cycle which has thick plates of 0.10" or greater and thick grids of 0.095" or greater.

A marine battery typically falls between a starting and deep cycle battery, although some marine batteries are true deep cycle batteries. Often, the labels "marine" and "deep cycle" are used interchangeably or together, which causes some confusion.

True deep cycle batteries are made by Crown, Deka, Lifeline, Rolls-Surrette, and Trojan. There are probably some others

For links to a lot of info on batteries see:

http://www.wanderthewest.com/forum/topic/15574-ultimate-battery-thread/


Regards,
Craig

Thanks, I don't have the camper on, but will check next week when I load it back on.

 

[radarcontact]

Good question...I believe it does, but my old memory is fuzzy on that..

What I gather is that yes a better monitor will give real time accurate system evaluations but the issue, if indeed I face this issue, is that the controller doesn't "know when to quit" and may over-charge the batteries [two 12v in my case]...

I will roll the beast out into the sun tomorrow and report back on whether or not I still get the "13.6" floating charge indication on solar power alone.

Phil

Reason I ask is that my Zamp 'doesn't know when to quit', and never went to float charge w/solar charging.