Best battery monitors? And low voltage cutoff?

[dlandersson]

Isn't "simple" in the eye of the beholder?

I'm pretty much a day sailer, I don't consider an fridge or AC "simple".

I agree with sumner on keeping it simple

Have you looked at Summer's mods? I do not think he keeps anything simple. He does do modifications that are very useful to him. looking at his designs they should be reliable. Just because it is simple does not make it more reliable. I have seen people make a nav light installation un reliable.

I beleive it was dlanderson that was the KISS guy. Rock and Roll BABY!!!!!!!!!

[BOAT]

Perhaps, but it still would be cool to be like kurz and be able to talk in German AND English! That's gotta be cool, right? Am i right!

[Seapup]

I like to be the "dumb" guy in the mix (ie: my avatar) because I know there are a lot of guys out there that want to know what you guys are talking about but are afraid to chime in because they don't want to look stupid.

Interesting tactic.


I don't have have an educated opinion on "best" which is why I tried to display the PBO article, sorry about the low resolution. Its a great "practical boat owners" resource. I have enjoyed learning a great deal from it I would not have gotten from forums. I can send the pdf article through email if you want to PM me.

First why do we even look at getting any of these monitors. They don't make our batteries last any longer unless we use the info we get from them.

Yup, My slipmate who is a great guy and friend takes home his deep cycle once or twice a season, or when stuff stops working to charge it and avoid paying for marina shore power. I gave him a free Harbor Freight voltmeter and showed him how it works and why to keep a battery topped off, but he was happy with his system. As long as its not "empty" like a gas tank he figures why charge it. "Sitting at 1/4 tank should be fine till spring or next time is his logic.

Any links for some you like. I"m interested in remote shunt models and also the wireless one...

This is the wireless one I am playing with, I have not installed it yet.



You can find them by searching "Multifunction Wireless DC Voltmeter" on ebay and they range from $25-35 and come with different shunt and metering options. You want one that states "2 way" if you want to monitor both charge and discharge.

http://www.ebay.com/sch/i.html?_odkw=Mu ... r&_sacat=0

Shunt- The only thing you connect are the two negative lugs and one positive wire to power the board, unless you want to add a relay for low voltage or other protection. Stays out of sight in the battery compartment.



The receiver can be mounted wherever and just needs needs a voltage to light up.



Power says "out" when going out and "in" when charging.

The screen is LCD that you can change to display the values you want on each line. The values on the right you scroll to with the arrows to enter to set. "O" is "over" and "L" is under. It will flash and trip the relay output when preset values are reached. There are more values if you keep scrolling. The bottom counts AH and displays battery percent (you have to tell it a starting value). No instructions came with mine.

[BOAT]

the post above from seapup is so far over my head it's not even funny, but i sure do like all those sparkly lights and buttons on the thing he pictured. I wish i could make stuff like that.
Sometimes I get the impression that there are a lot of MAC owners that are also pretty well versed in Electronics - like really deep into the stuff. I know your basic house wiring and 120 volt stuff but when you get down to the low voltage level with capacitors and transistors and resistors and all those circuit boards and stuff I am totally lost - I have no clue. You need some kind of professional schooling to know that stuff or you must have spent your summers at Radio Shack every year when you were a kid. It's just over my head - but I bet there are a LOT of other guys on this site who understand every word! (MAC owners seem to know this stuff).

[Jeremysxx]

i need this too

[korn_kid_12]

I like to be the "dumb" guy in the mix (ie: my avatar) because I know there are a lot of guys out there that want to know what you guys are talking about but are afraid to chime in because they don't want to look stupid.

Interesting tactic.


I don't have have an educated opinion on "best" which is why I tried to display the PBO article, sorry about the low resolution. Its a great "practical boat owners" resource. I have enjoyed learning a great deal from it I would not have gotten from forums. I can send the pdf article through email if you want to PM me.

First why do we even look at getting any of these monitors. They don't make our batteries last any longer unless we use the info we get from them.

Yup, My slipmate who is a great guy and friend takes home his deep cycle once or twice a season, or when stuff stops working to charge it and avoid paying for marina shore power. I gave him a free Harbor Freight voltmeter and showed him how it works and why to keep a battery topped off, but he was happy with his system. As long as its not "empty" like a gas tank he figures why charge it. "Sitting at 1/4 tank should be fine till spring or next time is his logic.

Any links for some you like. I"m interested in remote shunt models and also the wireless one...

This is the wireless one I am playing with, I have not installed it yet.



You can find them by searching "Multifunction Wireless DC Voltmeter" on ebay and they range from $25-35 and come with different shunt and metering options. You want one that states "2 way" if you want to monitor both charge and discharge.

http://www.ebay.com/sch/i.html?_odkw=Mu ... r&_sacat=0

Shunt- The only thing you connect are the two negative lugs and one positive wire to power the board, unless you want to add a relay for low voltage or other protection. Stays out of sight in the battery compartment.



The receiver can be mounted wherever and just needs needs a voltage to light up.



Power says "out" when going out and "in" when charging.

The screen is LCD that you can change to display the values you want on each line. The values on the right you scroll to with the arrows to enter to set. "O" is "over" and "L" is under. It will flash and trip the relay output when preset values are reached. There are more values if you keep scrolling. The bottom counts AH and displays battery percent (you have to tell it a starting value). No instructions came with mine.

I am very interested, but Do you have a wiring diagram for this unit? it should show it is being charged when the item in the boat that draw on the batteries are off and the Solar array is charging the batteries right?

[Flightfollowing]

I am very interested, but Do you have a wiring diagram for this unit? it should show it is being charged when the item in the boat that draw on the batteries are off and the Solar array is charging the batteries right?

Correct, as long as the device is a 2 way meter, and not a one way meter. The shunt would be wired between your battery post and the bus bar. But keep in mind if your solar array is charging at 5 amps and your using 5 amps of juice, the meter will read zero. Other options are installing a pair of 1 way cheap meters where you could wire them so one would show charge and the other discharge, so one would be at +5 and the other at -5 in the example above.
One reservation I have about the wireless options is needing to supply a little battery in the meter and the background current draw of the unit, a wired one would probably be less.

I think I just going to get one of these, for ultimate versatility and even troubleshooting:
http://www.amazon.com/Uni-T-UT210E-Curr ... l_huc_item

[grady]

Correct, as long as the device is a 2 way meter, and not a one way meter. The shunt would be wired between your battery post and the bus bar. But keep in mind if your solar array is charging at 5 amps and your using 5 amps of juice, the meter will read zero. Other options are installing a pair of 1 way cheap meters where you could wire them so one would show charge and the other discharge, so one would be at +5 and the other at -5 in the example above.
One reservation I have about the wireless options is needing to supply a little battery in the meter and the background current draw of the unit, a wired one would probably be less.

I think I just going to get one of these, for ultimate versatility and even troubleshooting:
http://www.amazon.com/Uni-T-UT210E-Curr ... l_huc_item

Correct but are you installing this meter for a Load, Battery charge, or Troubleshooting meter. The only thing that you realy need to know is, are you using battery power or not when you are under way.

[Catigale]

A battery isn't like a gas tank at all, and letting it sit at 1/4 charge all winter is very bad for it.

[LoHo]

Catigale is right on...leaving it partially charged for a long time is a death sentence. Keep it topped off and active at least monthly.

[grady]

They seemed to do a good job on the M2 SOC. It appears to work good. I will find out this summer.

[jimmy alonso]

Found a Blue Sea 1830 SoC M2 meter on eBay at a good price and installed the day before leaving for a 3 week trip to the BVI again.

Nice Big Shunt. Used a couple of ty wraps to fix to battery handle and two sided tape to battery.
Shunt goes on the Negative side of battery. On the Positive is a Blue Sea 30 Amp Fuse.



Installed here. At first the amps in/out arrow was pointing the wrong way, just reverse wires on the shunt.



Setup was easy, Battery is a West Marine 105AH AGM about 2 years old so set it up to less AH about I think 95 AH. When charged to 100% input that to Meter.
What I like best is the ability to see how the batteries behave and how many amp various equipment and different modes of operations use. Like Motoring, sailing, sailing at night or at Anchor. At what time Battery reaches 100% etc.

A Few Examples: Charging.

Motoring : Saw 10 to 12 amps max at 6 knots
Motor: On at idle only 5 amps there or less.
Solar 140 watts with good sun 9 amps /battery 100% about 1pm from average of 78% overnight

Discharge Examples :

Engel 2.4 amps when running
Autopilot, GPS, Depth Sounder, VHF : 2.5 to 3.5 amps
iPad .4
Cabin LED lamps .2 amps each
LED Running Lights .5 amps
Surface RT 2.2 amps (Surpised me that did)
Laptop on Inverter 2 amps

Also noticed when solar starts to kick in the morning the Yandina Combiner would close and 10 amps would come from the Start battery to the House battery then fall down till the voltage on the start would fall below the close value and open the Yandina Combiner.

[grady]

I went ahead and replaced the 500a shunt with a 100a shunt to make it more accurate. (I was having some noise issues) Also upgraded the shunt wires to shielded. But I do have a more complex electrical system than most. If you do that make sure you upgrade to the latest software. When I changed mine out I had issues and when I called them they found out they had a big bug in the software. No mater what shunt value you told it It did not rescale. I had a 100w solar panel charging at 9A. I knew there was an issue! I ether had purchased the best solar panels in the world, or it was indicating incorrect.

[jimmy alonso]

My first thought was to replace the shunt also. Were never gonna see any where close to 500 amps or 50 either, doesn't seem right to measure a half a amp on a 500 amp scale.

Made my twisted wire by using a drill to twirl them.
Think I have the latest software will check again later. Sent for the dual USB/mini usb for upgrading.

Would like to put the shunt on the start battery to get an idea of the cranking amps while starting the engine. I have a 100 amp Blue sea fuse there but I think its too much.

The Solar Charge Controller has its own amp meter and the math is spot on. Plus I had measured almost everything with a Fluke meter.

[C Buchs]

installed the day before leaving for a 3 week trip to the BVI again.

Some day I would like to be able to be able to say this I love that you added "again". Awesome

Jeff