How to monitor power consumption ?

[peterjaw]

Good day, captains,

I have only 2 batteries, no A/C system nor generator on boat. The capacity of each battery is 100Ah.

Last weekend, I went out for fishing. When arriving at the fishing spot, I turned off the engine but the
fish finder and the plotter were kept working. After roughly an hour or so, when I wanted to started the
engine, I turned the key to "On" position, a low battery voltage warning (11v) popped out. I could start the engine
though.

It took about 30 minutes from marina to fishing spot and there's nothing wrong when I started the enging
in the marina. When I returned to marina, the voltage reading was 13.8v.

My plotter is Simrad NSS EVO3, 9". According to its manual, it consums about 2A per hour.

I wonder how to monitor the power (electricity) consumption, is there any device or gauge that I can
buy for this purpose? Or do yo have any suggestion for this situation?

 

[BartW]

Het Battery monitor such as the Victron BMV700, can display consumption, battery charge status , battery voltage, etc and it can be programmed to give a alarm when values are reaching a certain level.

 

[jimmy_the_builder]

Het Battery monitor such as the Victron BMV700, can display consumption, battery charge status , battery voltage, etc and it can be programmed to give a alarm when values are reaching a certain level.

Coincidentally I have one of those in front of me right now to fit to the boat today...

 

[petem]

Good day, captains,

I have only 2 batteries, no A/C system nor generator on boat. The capacity of each battery is 100Ah.

Last weekend, I went out for fishing. When arriving at the fishing spot, I turned off the engine but the
fish finder and the plotter were kept working. After roughly an hour or so, when I wanted to started the
engine, I turned the key to "On" position, a low battery voltage warning (11v) popped out. I could start the engine
though.

It took about 30 minutes from marina to fishing spot and there's nothing wrong when I started the enging
in the marina. When I returned to marina, the voltage reading was 13.8v.

My plotter is Simrad NSS EVO3, 9". According to its manual, it consums about 2A per hour.

I wonder how to monitor the power (electricity) consumption, is there any device or gauge that I can
buy for this purpose? Or do yo have any suggestion for this situation?

Peter, there's no way that use of a plotter/fish finder for an hour should discharge the battery as you are experiencing. I'd get to the bottom of this issue (which will be either 'user error' or a fault with the boat) before complicating things with battery monitors.

 

[JerseyDiver]

Doubt there was anything wrong. The load taken from the starter would be enough to cause a blip to the voltage on plotter which in turn caused the alarm.

 

[petem]

Coincidentally I have one of those in front of me right now to fit to the boat today...

Nice bit of kit. I want !

Can you monitor the battery state remotely though?

 

[BartW]

Peter, there's no way that use of a plotter/fish finder for an hour should discharge the battery as you are experiencing. I'd get to the bottom of this issue (which will be either 'user error' or a fault with the boat) before complicating things with battery monitors.

the battery monitor can help you to understand whats going on, (for approx £100)

but you're right, a plotter fishfinder wouldn't discharge so much from the batts,
I guess that these battery's are a bit worn..

 

[petem]

I get that Bart (although the info he'd get is limited?) but remember this is a brand new boat and a simple one to boot. I wonder if installing a battery monitor (and messing about with the thing in general) might just give the dealer something to blame or otherwise invalidate the warranty? Remember we're talking about Taiwan (I think?) here so hardly the centre of the pleasure boating universe. As they say "Keep it simple"!

 

[BartW]

Can you monitor the battery state remotely though?

I believe there exists a internet link interface for the latest model, (the 700)

but I use the YS6, the latest alarm system from Yacht sentinel for that, it shows many other data on your iphone
and it does not need internet, it works via mobilephone network, subscription is included in the purchase (pricing is on their website)

 

[BartW]

...but remember this is a brand new boat and a simple one to boot. I wonder if installing a battery monitor (and messing about with the thing in general) might just give the dealer something to blame or otherwise invalidate the warranty? Remember we're talking about Taiwan (I think?) here so hardly the centre of the pleasure boating universe. As they say "Keep it simple"!

oops I missed that, agree,

 

[mcanderson]

Coincidentally I have one of those in front of me right now to fit to the boat today...

I'm already looking forward to your detailed post on how you installed it!

 

[simonfraser]

if you dont charge it up for long enough on the way back you wont be charging the batteries well enough

check the battery voltage b4 you start it next time, after they have had a rest, 12.7 is good, less than than and you may not be charging them sufficiently.

 

[petem]

I'm already looking forward to your detailed post on how you installed it!

+1. Will be expecting pics as well!

 

[5teve]

I have used similar to this one and am quite impressed. I got inspiration from Wayne and the plant pot as he uses one also. Works from several metres and if wireless is an issue can be hardwired via usb. For the money it's spectacular. I did have a small calibration issue but a bit of Google work solved that. I have my whole house side running through it. You can set battery capacity and it's reads % based on this. It has relay control to alarm or switch off based in high or low voltage. Oh and it's bi directional too...

https://www.ebay.com/itm/Wireless-L...r-Meter/202440667344?var=&hash=item2f226770d0

Steve

 

[Portofino]

On a wider note this boat I currently have has the facility to measure AH out or gone out and when on charge AH going back .
It’s useful .
At anchor after what feels like a long day on a busy boat ( loadsa fringed opening and toilet motor + cupboard int lights usage ) with the dial I can see what’s what make an informed decision of what to do if the house bank is looking battered .
Geny up or adjust the itinerary,ie start up and motor off .
Additionally when on charge from the geny I can work out when to stop the geny .At the dock I can also see the states .
Engine bank abviously negliable discharge after a run back , but the domestic I can see if the mains charger is bulking , floating or what ever as I can see how many AH it’s shovimg in .
Also with the mains charger on I can kinda work out exactly how long it takes to top up the domestic after a long day out at anchor .
It’s the rectangular guage rhs ish with the toggle switch under , one side is engines other domestic .
Shows discharge and recharge if the charger is on .
Also have V meters but it’s the Ah that seems to change .
View attachment 73845

 

[jimmy_the_builder]

I'm already looking forward to your detailed post on how you installed it!

Here is my detailed post about how I installed it: I cut a hole in a panel for the head unit. I ran a cable from there to the battery box. I screwed the shunt to the wall by the battery box. There are no pictures. The end

 

[petem]

Here is my detailed post about how I installed it: I cut a hole in a panel for the head unit. I ran a cable from there to the battery box. I screwed the shunt to the wall by the battery box. There are no pictures. The end

Killjoy.

Incidentally, what prompted you do fit one?

 

[jimmy_the_builder]

Killjoy.

Incidentally, what prompted you do fit one?

I still have the OE charger on the boat, which is quite elderly and doesn't show a charge rate, so I wanted something that would give me some indication of what was going on with the batteries. Talked to the Victron dealer at the boat show and they suggested this unit so I bought one. That's it really. I haven't programmed it up yet, I'll do that next time.

As an aside - blimmin fantastic day down here today, t-shirts and shorts all round. Lovely.

 

[petem]

I still have the OE charger on the boat, which is quite elderly and doesn't show a charge rate, so I wanted something that would give me some indication of what was going on with the batteries. Talked to the Victron dealer at the boat show and they suggested this unit so I bought one. That's it really. I haven't programmed it up yet, I'll do that next time.

As an aside - blimmin fantastic day down here today, t-shirts and shorts all round. Lovely.

Apols to PeterJaw for the thread drift.

I'm the same as you, having what is probably an even older Jenelec charger. I do have half a mind to get a modern charger with a trickle mode with the additional benefit of being able to the port side battery if I choose. Plus a battery monitor as you have fitted today. Could probably do it for a couple of hundred quid.

 

[jimmy_the_builder]

Apols to PeterJaw for the thread drift.

I'm the same as you, having what is probably an even older Jenelec charger. I do have half a mind to get a modern charger with a trickle mode with the additional benefit of being able to the port side battery if I choose. Plus a battery monitor as you have fitted today. Could probably do it for a couple of hundred quid.

I still have the original architecture where the start battery is only ever charged by the engines, there's no mains charger. What is noticeable is that the start battery lasted a lot longer than the domestics, which are constantly on charge - I replaced the start battery this year, and it was c.10 years old. I only get 3/4 years out of the domestic batteries. That said, I guess a more modern charger might improve that a bit. I think my longer-term plan will be to follow Bartw's advice and replace the Jenelec charger with a Victron charger-inverter.