How to monitor power consumption ?

petem said:
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.
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P, unless you are aware of some ways of purchasing serious electronic components at HUGE discounts (in which case I might also be interested! :D), a two channels smart battery charger of decent power plus a battery monitor which can be bought for 200 quid overall is something I'm happy to see installed in someone else's boat... :rolleyes: :p
 
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jimmy_the_builder said:
I think my longer-term plan will be to follow Bartw's advice and replace the Jenelec charger with a Victron charger-inverter.
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Having followed the same advice from him already some years ago (fitting a 3kW Multiplus to my previous boat), I can confirm that it's a good one. :encouragement:
 
MapisM said:
P, unless you are aware of some ways of purchasing serious electronic components at HUGE discounts (in which case I might also be interested! :D), a two channels smart battery charger of decent power plus a battery monitor which can be bought for 200 quid overall is something I'm happy to see installed in someone else's boat... :rolleyes: :p
Click to expand...

Eeek, looks like I massively underestimated the cost! Looks like I'll be sticking with my 50amp charger for a while after all.
 
Thank you very much for all inputs.

I use multimeter to check the batteries last night and I got 13.219 V. I think this shows the battery is healthy and fully charged on my way back to marina.

So now I can only guess there are 2 posibilities:
1. False alarm ---- but I still need to find out the reason, otherwise if it becomes a true alarm someday then I won't be able to know.

2. "Power leak" (sorry that I don't know how you say this in English) ---- that means there is something wrong in the circuit and the
electricity leak to "ocean". Again, I have to find out the spot(s). But how?
 
peterjaw said:
Thank you very much for all inputs.

I use multimeter to check the batteries last night and I got 13.219 V. I think this shows the battery is healthy and fully charged on my way back to marina?
Click to expand...

Not really ,it’s the amps used / depleted and when charging ( engine or AC charger ) how many and how fast the Ah go back that’s a more accurate measure of bat health .
For example for engine starting it’s the CAA - Cold Cranking Amps that matters not the voltage .
Voltage is just the potential the Amps are it’s ability to deliver and over what time tells you it’s the real ability to be able to deliver something useful on the boat .

Having said that the volts if low indicate there’s a problem ie they say 12.6 or something it’s ready to change out if it can’t reasonably hold that .

Anecdotally last autum our engine bank V looked ok. 27 V so the pair was over 13 . something each ?
Engines would not start with out the x over switch , but using the Ah guage I mentioned ^^^^ I could see they were depleted/ depleting very quickly or more than usual after a start ,In other words not enough power to knock the skin off a rice pudding and I was scapping the dregs of the Ah left turning an engine ,
Even thought the volts looked ok .
A pair of new batts - normal service resumes and the Ah discharge and recharge is ok engines burst into life .

Same with the domestic bank at anchor the V appear ok or tiny movement down its the Ah that empty noticbly .
They say deep discharges , too many shorten the bats life , some say don,t go lower than 50 % , in a rule of thumb way .
It’s a big subject there’s different types of bat .
All I do with my two domestic 180:Ah = 360 capacity is recharge after a 60-80 Ah drop , which is miles away from 50 % .

Point is I can see where I,am looking at the Ah side of things easily, but your point of a 13.219 V drop to something else say 13.197 V does not tell you much really imho

Being an all electric boat and happy with running the geny we geny up to cook , Aircon before bed and boil the kettle anyhow , or as said after a prolonged period @ anchor just a hour or so to top up .
 
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The way I see it is this ——
Take a petrol tank .

The amps show you the level the volts tell you the volatility.

If you take a egg cup full out and place a lighted match near it = whoosh it goes up

But it doesn’t tell you how much is in the tank left , where as the Ah is the level guage .
So knowing the Ah you can manage the level .= not run dry , know what’s left , know how much to top up etc .
 
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jimmy_the_builder said:
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 :D
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yeah right,

and now tell us all about routing thick earth cables about to the thing then!
how well is the el. panel of the targa and what you had to move, add, built new cables etc to get it going?

wasn't a joyfull evening connecting mine I can tell you (but it was an opportunity to tidy up lots of stuff on that bulkhead...)

V.
 
AllanG said:
The Victron BMV 702 is the monitor with connections for two separate batteries.
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is OP setup up two different banks? or just two batteries connected to each other?
If the former, you could use the 702, else 700.

Having said that and for anyone about to buy one, I'd go for the 702 if I'd buy again as this way you can use the extra capability of measuring temp in the batteries on the house bank (instead of monitoring a second bank that is!).
TBH, I don't find any serious reason to monitor engine bank, I can just see the Vmeter on the dash.
However the 700 has proven extremely useful in knowing what's going on really with my home batteries.

V.
 
vas said:
yeah right,

and now tell us all about routing thick earth cables about to the thing then!
how well is the el. panel of the targa and what you had to move, add, built new cables etc to get it going?

wasn't a joyfull evening connecting mine I can tell you (but it was an opportunity to tidy up lots of stuff on that bulkhead...)

V.
Click to expand...

It was easy enough because I had a new battery cable made up that I bought with me - but that said, I didn't like the resulting layout so I've disconnected it and I'm going to get some more cables made up and do this bit of the installation again. The cables themselves are easy enough because they are only 95mm2.
 
AllanG said:
The Victron BMV 702 is the monitor with connections for two separate batteries.
Click to expand...

its not clear from available info if the two battery's (from OP) are separate (normally it would)
OR
if there are two battery's installed in parallel, for having more capacity.

the BMV 702 can indeed be connected to two separate batt's, but keep in mind that for the second batt, usually the engine batt, there is no shunt in the system,
so the available info on the BMV display is very limited,
from the info from OP, it seems to be the engine batt that was drained, and normally you wouldn't have the main monitor cirquit with shunt of the BMV702 on that batt....

FWIW
in my boat I have 2 x BMV units (one for engine bank and one for domestic bank) but that would be overkill in most other boats
 
This is my first boat and I am like a blank paper about the circuit and battery.

I posted a question before for asking about the battery switch and it seems that my 2 batteries
are in parallel .

http://www.ybw.com/forums/showthread.php?507304-Battery-switch-how-do-I-use-it

----------------------------------------------------------------------------------------
Bauba,

Since I have 2 parallel (I guess) batteries, if I carry a portable spare battery as you do,
when I want to jump start the engine, I need to connect the positive (+) of portable
battery to the positive (+) on battery 1 and connect the negative (-) of portable battery to the
negative (-) on battery 2, right?
 
peterjaw said:
This is my first boat and I am like a blank paper about the circuit and battery.

I posted a question before for asking about the battery switch and it seems that my 2 batteries
are in parallel .

http://www.ybw.com/forums/showthread.php?507304-Battery-switch-how-do-I-use-it

----------------------------------------------------------------------------------------
Bauba,

Since I have 2 parallel (I guess) batteries, if I carry a portable spare battery as you do,
when I want to jump start the engine, I need to connect the positive (+) of portable
battery to the positive (+) on battery 1 and connect the negative (-) of portable battery to the
negative (-) on battery 2, right?
Click to expand...
I’m not the best person to ask, but I think you can use the positive and negative on the same battery. This is helpful as these jump start kits have short jumper leads.
Your picture is interesting. You should, after you turn off your engine, switch to either 1 or 2 but not 1+2. This will preserve at least one battery at full power to start your engine. If for example you choose 1 after you switch off your engine, then when you go to start put the switch on either 2 or 1+2. (You can alternate each time you go out so that you wear the batteries evenly
 
Bouba said:
I’m not the best person to ask, but I think you can use the positive and negative on the same battery. This is helpful as these jump start kits have short jumper leads.
Your picture is interesting. You should, after you turn off your engine, switch to either 1 or 2 but not 1+2. This will preserve at least one battery at full power to start your engine. If for example you choose 1 after you switch off your engine, then when you go to start put the switch on either 2 or 1+2. (You can alternate each time you go out so that you wear the batteries evenly
Click to expand...

yes exactly, you don't need a BMV in your setup, (after looking to your setup in the other thread)
only use 1 or 2, alternating, never 1+2
this makes shure you alway's have a backup battery

I would add a Victron Cyrix 12/24V 120A to your setup,
this automatically links the battery's when the alternator is charging one of both
 
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