Battery Monitors

[sailorboy1]

Originally Posted by skipmac

I expect once I'm onboard full time and get used to the systems I will look at it even less often.

Good luck with that because looking at it is also like smoking crack (from what I have heard). You just can not help yourself looking at it

Which is the point of the thread.

[ontherocks83]

Originally Posted by sailorboy1

Good luck with that because looking at it is also like smoking crack (from what I have heard). You just can not help yourself looking at it

Which is the point of the thread.

I'll second that. All I have right now is a volt meter and I look at it constantly. Comparing what the reading is with loads on and off. Trying to calculate in my head if the loads I have had on line up with what the reading should be. And then there is always the "well the batteries seemed to do much better last year". It really doesn't stop.

[onestepcsy37]

Originally Posted by noelex 77

There are some subtle shade of grey between "dead" and "not dead". This distinction is where a battery monitor is useful.

I agree there are subtle shades. But overall I'm afraid we will all just have to agree to disagree. We each make a choice about what kind of stuff we put on our boats. For instance, I have a navtex receiver. I have yet to meet a single yachtie in this area who has even heard of it....

[skipmac]

Originally Posted by sailorboy1

Good luck with that because looking at it is also like smoking crack (from what I have heard). You just can not help yourself looking at it

Which is the point of the thread.

You're right. I'm starting get a craving for a battery monitor fix. Think I'll go out to the boat right now and LOOK at it.

[sailorchic34]

Originally Posted by cwyckham

How do you know what your power use is each day?

LOL, I use about 50-60 amps a day based on how many amps the solar panels put out a day. I have a simple boat with led lights, a small netbook selected for its low power consumption, a cell phone I charge once a week and my 120V fridge which is the energy pig at 40-55 amps a day (depending on whether I'm in the central bay or delta).

I actually calculated amps used by assuming full charge and then taking a resting voltage reading after a know time. That give me about how many amps are used. It really does not vary that much day to day.

Really I don't even worry about it. I have two solar panels (230 watts total) that have both sets of batteries recharged to float voltage by 2 PM pretty much every day. Sometimes with cloudy weather, it takes longer and sometimes I have to run Mr Honda or Purple my diesel. No biggy.

The volt meter is there to see if there is a problem with the solar controller (bad fuse one day) or batteries (bad cell every other year or so). With my house bank divided into two sides the volt meter allows me to compare resting voltage.

[skipmac]

Originally Posted by onestepcsy37

I agree there are subtle shades. But overall I'm afraid we will all just have to agree to disagree. We each make a choice about what kind of stuff we put on our boats. For instance, I have a navtex receiver. I have yet to meet a single yachtie in this area who has even heard of it....

I've heard of Navtex but thought it was a European phenomenon however google informs me you can get Navtex transmissions in the US as well.

So, how do you like it?

[sailorboy1]

Originally Posted by skipmac

You're right. I'm starting get a craving for a battery monitor fix. Think I'll go out to the boat right now and LOOK at it.

I don't know why you would even have batteries, let alone a battery monitor

For those CF members not in the know Skip's boat has been sitting in the woods for a good 3 years (longer I think but I have trouble remembering stuff that long). The nature society now has a court order not allowing him to move it due to the number of squirrels, birds, and other woody creatures that now "cruise" on the boat.

[sparrowhawk1]

I just installed an amp hour meter today. Ironically so it appears, I installed the meter so I wouldn't have to keep checking the batteries.. when you're only using voltage you have to check it in the morning, check to see when it goes into float , and after the Sun Goes Down( using solar as my main charging source) now I don't do this everyday but if I want to know approximately how discharged they are I will ( or more precisely if they're fully charged) Now hopefully I will have a much more accurate measurement with no work

[skipmac]

Originally Posted by sailorboy1

I don't know why you would even have batteries, let alone a battery monitor

For those CF members not in the know Skip's boat has been sitting in the woods for a good 3 years (longer I think but I have trouble remembering stuff that long). The nature society now has a court order not allowing him to move it due to the number of squirrels, birds, and other woody creatures that now "cruise" on the boat.

How can I reply?

Slow but steady wins the race.

Take your time and do it right the first time.

Boat projects always cost twice and much and take twice as long as you estimate, even if you've done it before and think you know.

Bottom line, when I splash this boat will be in better condition than the day it came out of the Pearson factory.

[sailorboy1]

Originally Posted by skipmac

Take your time and do it right the first time.

But you have to FINISH! Fess up to the group on how you told me you would be in the water before me in the spring (of course that was 2 years ago).

sparrowhawk - welcome to the crack club, be ready to "know" too much, yet so little

[Capt.Don]

I've been intrigued by the idea of installing a battery monitor. However, I keep coming back to two concepts: (1) Don't discharge more than 50%. Per the battery manufacturer, rest 12.32 volts, load 11.8 volts . (2) I've been monitoring my usage using amp meter. Keep a log of what's running and check amps used during the day. From that I can figure how long before I have to charge.

Another idea is the "Watt Meter", used by RC folks. These inexpensive gadgets will work to figure out individual items. These can be wired in series and monitor uage. I think these go for about $20.

[Maine Sail]

Originally Posted by Capt.Don

I've been intrigued by the idea of installing a battery monitor. However, I keep coming back to two concepts: (1) Don't discharge more than 50%. Per the battery manufacturer, rest 12.32 volts, load 11.8 volts . (2) I've been monitoring my usage using amp meter. Keep a log of what's running and check amps used during the day. From that I can figure how long before I have to charge.

Another idea is the "Watt Meter", used by RC folks. These inexpensive gadgets will work to figure out individual items. These can be wired in series and monitor uage. I think these go for about $20.

This can be misleading if applied in a generic fashion as many folks try to do.

As of this very moment I have a single group 31 110Ah AGM battery on my capacity tester for a 20 hour discharge test.. It is set at the batteries 20 hour rate, 5.5A, and has been running since early this morning at a 75F case temp.

With 64.9Ah's removed from the battery (41%SOC) the loaded voltages is currently 12.12V (NIST Calibrated Fluke 179)......

Voltage can be used but the voltage graphs for your bank need to be developed for a reference point. All batteries have slightly differing voltage performance so applying generalities can cause one to be off by 20% or more....

For example by the time this battery hits 11.8V it will likely be at 33-35% SOC at 5.5A.. Course at a 2.5A load that again would be entirely differnt and at 10A would also be entirely different again..

Drawing this bank "loaded" to 11.8V would push it pretty deep into the cycling depth... For your batteries 11.8V may be spot on and I suspect you've confirmed this but a lot of folks try to use generic voltage charts etc...

My point here is one really need to know their own batteries voltage performance if they want to use voltage as a guide... Again, it can be done, but it takes time to develop these data sets for your own batteries.

I have had numerous customers using "generic" voltage charts that show 12.6V as full when their own batteries rest full at 12.74V. That is a 10%+ capacity discrepancy which on a 400Ah bank turns into 40 Ah's or an entire days energy they are off by it can also mean they are chronically under charging if happy with 12.6V..

Resting voltage works quite well but it takes too much time..

[Neptune's Gear]

I use a battery monitor, and I think is a great tool. Not perfect, but pretty good. I look at it about once a day, and that only to confirm everything is about the same as any other day...
Oh yes, and I have Gel- hybrid batts, now in their 7th season, 3 years of which was full time cruising. They seem to have dropped only a little in capacity, but they are well looked after, and that's partly to do with the batt monitor :-)

[cwyckham]

Originally Posted by sailorchic34

LOL, I use about 50-60 amps a day based on how many amps the solar panels put out a day. I have a simple boat with led lights, a small netbook selected for its low power consumption, a cell phone I charge once a week and my 120V fridge which is the energy pig at 40-55 amps a day (depending on whether I'm in the central bay or delta).

I actually calculated amps used by assuming full charge and then taking a resting voltage reading after a know time. That give me about how many amps are used. It really does not vary that much day to day.

Really I don't even worry about it. I have two solar panels (230 watts total) that have both sets of batteries recharged to float voltage by 2 PM pretty much every day. Sometimes with cloudy weather, it takes longer and sometimes I have to run Mr Honda or Purple my diesel. No biggy.

The volt meter is there to see if there is a problem with the solar controller (bad fuse one day) or batteries (bad cell every other year or so). With my house bank divided into two sides the volt meter allows me to compare resting voltage.

That makes sense since you are able to wait until you hit resting voltage and your charging is more than ample, so accuracy isn't that important. A lot of people are really marginal on charging vs their use, so extra real time accuracy is valuable.

(I think you mean amp-hours, not amps.)

[Ex-Calif]

Originally Posted by sparrowhawk1

I just installed an amp hour meter today. Ironically so it appears, I installed the meter so I wouldn't have to keep checking the batteries.. when you're only using voltage you have to check it in the morning, check to see when it goes into float , and after the Sun Goes Down( using solar as my main charging source) now I don't do this everyday but if I want to know approximately how discharged they are I will ( or more precisely if they're fully charged) Now hopefully I will have a much more accurate measurement with no work

What meter did you install. I have been looking for one...

So far no one has fessed up here as to what they are using.