Recommend or Suggest a Battery Monitor with ....

[EuroTrotters]

Number of days or hours of useable battery available please?

 

[David and Sally]

How will the monitor know what load you are going to put on the battery in order to work out the hours left?

 

[Pausim]

Number of days or hours of useable battery available please?

I have a Victron BMV 700 with bluetooth dongle. The app shows time remaining but I never take much notice of it because it shoots up and down as I turn things on and off, it can only base the calculation on the current draw. I find the % charge, Ah used and current draw are a far more useful guide. I fairly quickly learned what my daily usage in Ah adds up to and just divide the current state of charge by that to estimate how long it should last.

Victron was the only make with proper settings when I bought my BMV. Without efficiency and Peukert‘s exponent that are set to the battery the accuracy is at best a rough estimate. There was even one monitor that sometimes shows a charge of 104% which is a physical impossibility. I think it was because there was no allowance for battery efficiency so it was registering that you had put back more than you had taken out.

 

[EuroTrotters]

How will the monitor know what load you are going to put on the battery in order to work out the hours left?

constant average algorithm I guess

 

[EuroTrotters]

I have a Victron BMV 700 with bluetooth dongle. The app shows time remaining but I never take much notice of it because it shoots up and down as I turn things on and off, it can only base the calculation on the current draw. I find the % charge, Ah used and current draw are a far more useful guide. I fairly quickly learned what my daily usage in Ah adds up to and just divide the current state of charge by that to estimate how long it should last.

Victron was the only make with proper settings when I bought my BMV. Without efficiency and Peukert‘s exponent that are set to the battery the accuracy is at best a rough estimate. There was even one monitor that sometimes shows a charge of 104% which is a physical impossibility. I think it was because there was no allowance for battery efficiency so it was registering that you had put back more than you had taken out.

Does this connect to the Multiplus ?

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[funflair]

Our Victron smart shunt is currently showing time remaining as infinite but that is just a snap shot based on more power going in than out, if I turn on the inverter to make coffee or boil the kettle it will sy something completely different, so basically pretty meaningless unless you run a steady load.

 

[andyman]

Over 30 years of caravan and motorhoming. My battery monitor has been,If I turn the lights on and they come on the battery is good.

 

[Two on Tour]

I take that a fuel gauge in your car and van are just as erelivent then,?

 

[Richard n Ann]

My NASA BM2 shows hours until discharged

 

[berni109]

As has been said nothing can know how much you are going to use in future. Percentage of battery remaining is the normal measure and once you know your useage pattern then you can guess fairly accurately.
Question is how much do you want to pay? And do you want a well known brand (probably made in china) or a Chinese one.
I have used a juntec coulomb counters for a while and for £25 they've been brilliant. Recently changed to their bluetooth model which has gone up in price a lot recently.

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[Lenny HB]

I have a BMV700 but the BMV712 is better it has the bluetooth built and a relay you can program also measures the starter battery voltage. The Smartshunt is similar except no relay or display so you have to use the app.
The Bluetooth app is by far the best way of seeing all the parameters.

The percentage state takes a lot of time to get it reading fairly accurately with lead batteries but it is supposed to be good with Lithium. I go by current used if I want to know the exact state of my batteries.

A lot of people forget to adjust their battery capacity each year, you need to reduce it by 2.5% a year as that is the approx decline in lead batteries.

 

[MalibuChap]

We have junctek kl 110, 100 amp shunt, which is plenty for us, with no inverter. About £20 delivered from AliExpress.
It's been brilliant for us to make sure we don't use more than 50 percent battery capacity.
Previously we couldn't tell because voltage dropped in use.
Bluetooth App works quickly and well.
We were able to install the shunt directly on the battery negative terminal.
For £20 what's not to like!

 

[nicholsong]

I have a very simple battery monitor -me, very simple.

I check the voltage after batteries have been at rest for 1 hour, after dark, or it registers solar charging voltage. I know we can last 3 days but don't know beyond that, as we have never stayed longer and when driving the B2B tops it up in no time.