Battery Monitors

[Gibbo]

This may open up a can of worms.

 

I'm just coming to the end of the design and debugging of a rather complex battery monitor (however not the sort that is applicable to the average boat owner as it's really far too complex and expensive plus it requires the use of further external devices - for instance it doesn't even have a display) that incorporates more or less every possible feature that man could devise.

 

We've been discussing transferring parts of that design to a new standalone battery monitor and my experience is that actually asking the sorts of people who would be using it, "what do you want?", usually scores dividends and often a few surprises. Many manufacturers seem to miss this stage with the result that they simply produce yet another version of something that has been available for 25 years (the same device with a light in a different place).

 

Some of you use amp hour counters, some of you use SmartGauges, some use voltmeters, some use ammeters, some use a combination, some use nothing. Some are happy with what they have, others less so, some have tried one, not liked it and moved onto something else. None of them are perfect (battery monitoring is not, depsite its apparent simplicity, an exact science) but different ones suit different people. Much of it comes down to the owner's knowledge and experience in what they can actually make work for them.

 

Given a blank sheet, what would you want of a battery monitor? What features would you demand? What would you wish for? What would be a "like" but not a demand? What would be an "absolute must"?

 

Are you currently using something that's almost right for you but you wish it also had such and such a feature?

 

Is there something in particular that stopped a certain device from working for you?

 

Remember that every additional feature will cost money and some people even squeal at the cost of a voltmeter let alone something costing hundreds of pounds. However this device is, at present, aiming to be the Rolls Royce of battery monitors. The budget market is already pretty well covered. Whilst some people avoid expensive equipment, there are just as many who love it.

 

As a boater, and having designed several in the past, I think I have some idea of the overall ideal device but input will be gratefully received and noted even if I disagree with it. The device wont be for me therefore my opinion is worthless.

 

The design process on this sort of device is very long so it will be some time before it sees the light of day but if anyone (or more than one) came up with a brilliant idea I'm sure I could pull some strings and get you allocated as a "beta tester" (which means you'd get one for free ).

 

PS. I have just spoken to "management" and this product has now been given the green light. I start the design when the current two are finished which should be about the end of January.

[nb Innisfree]

I've got 8 knackered 125ah AGMs and beacause of that amount they still give me reasonable service with still fairly short charge times, problem is as they are below 50% of their original capacity (and seem quite stable at that) but my Smartgauge therefore isn't accurate, can that be addressed? + I use our BMV for ah counting and alternator output, maybe you are already incorporating a shunt in the new one but it would be handy to have it all in one with an option to select a readout of amps, voltage and percentage alongside each other without having to cycle back and forth, as your new one intends to have no readout maybe an optional separate add on plug in display?

 

PS I'm all excited!

Edited November 26, 2010 by nb Innisfree

[Albion]

This may open up a can of worms.

 

snipped for brevity

 

OK then, I'll start. I like the Smartgauges that I have had on two boats now (combined with Smartbank on the previous one). I think I would like to see a current display. On my present barge I have both a Smartgauge (my specified instrument) and a Victron 602 (the boat-builders standard instrument). I only use the SG in the main but occasionally refer to the 602 for charging current read out. My only other suggestion for any improvement of the SG is to make it a little bit more robust and slick looking. The switches are definitely a poor-feel-item and I think they could be improved to a real, neat, switch or touch screen method. It definitely looks like the poor relation in the style stakes for example but, despite that down side, I wouldn't choose to not have one.

Roger

[Gibbo]

as your new one intends to have no readout maybe an optional separate add on plug in display?

 

Yes the new one will have a display. It's the one I'm just finishing that doesn't.

 

What sort of display would be desired?

 

All comments being noted.

[Tony Brooks]

This may open up a can of worms.

 

I'm just coming to the end of the design and debugging of a rather complex battery monitor (however not the sort that is applicable to the average boat owner as it's really far too complex and expensive plus it requires the use of further external devices - for instance it doesn't even have a display) that incorporates more or less every possible feature that man could devise.

 

We've been discussing transferring parts of that design to a new standalone battery monitor and my experience is that actually asking the sorts of people who would be using it, "what do you want?", usually scores dividends and often a few surprises. Many manufacturers seem to miss this stage with the result that they simply produce yet another version of something that has been available for 25 years (the same device with a light in a different place).

 

Some of you use amp hour counters, some of you use SmartGauges, some use voltmeters, some use ammeters, some use a combination, some use nothing. Some are happy with what they have, others less so, some have tried one, not liked it and moved onto something else. None of them are perfect (battery monitoring is not, depsite its apparent simplicity, an exact science) but different ones suit different people. Much of it comes down to the owner's knowledge and experience in what they can actually make work for them.

 

Given a blank sheet, what would you want of a battery monitor? What features would you demand? What would you wish for? What would be a "like" but not a demand? What would be an "absolute must"?

 

Are you currently using something that's almost right for you but you wish it also had such and such a feature?

 

Is there something in particular that stopped a certain device from working for you?

 

Remember that every additional feature will cost money and some people even squeal at the cost of a voltmeter let alone something costing hundreds of pounds. However this device is, at present, aiming to be the Rolls Royce of battery monitors. The budget market is already pretty well covered. Whilst some people avoid expensive equipment, there are just as many who love it.

 

As a boater, and having designed several in the past, I think I have some idea of the overall ideal device but input will be gratefully received and noted even if I disagree with it. The device wont be for me therefore my opinion is worthless.

 

The design process on this sort of device is very long so it will be some time before it sees the light of day but if anyone (or more than one) came up with a brilliant idea I'm sure I could pull some strings and get you allocated as a "beta tester" (which means you'd get one for free ).

 

PS. I have just spoken to "management" and this product has now been given the green light. I start the design when the current two are finished which should be about the end of January.

 

 

I accept that I may not be a typical user but FWIW I use an analogue ammeter in the alternator output and a voltmeter switchable between engien and domestic battery voltages. Now I have a solar controller with a digital volatge display I tend to cross check the analogue one against the digital one at appropriate times. This has worked well for over 10 years. I use a hydrometer to test the batteries when either the topping up or the ammeter/voltmeter readings taken over time suggests it may be prudent. I seem to be getting 4 years plus out of the domestic bank without any mains charging.

 

I would like a reliable indication of battery SOC shown in any form and would buy a Smartguage if I thought it would allow me to extend my battery life. I would also like an adjustable, mutable beeper to warn when the voltage got to (in my case) 12.2 volts but that is because I am lazy an do not want to walk down the boat to monitor the voltage during the evening.

 

I would question the need for any more features and feel the SG should do all that is required.

[nb Innisfree]

Yes the new one will have a display. It's the one I'm just finishing that doesn't.

 

What sort of display would be desired?

 

All comments being noted.

 

LED would be nice as it will only need to be lit up momentarily so consumption not a problem. A list of readouts together so they can be compared to each other to give an instant 'picture' One pain in the arse is having to keep trudging to the back of the boat to see how the charging's going, so, how about a wireless readout? Now that would be great! carry it around the boat if you want or stick it somewhere convenient while watching telly or having a piss up! Nice to observe charging behaviour in comfort, a group observation would be fun for us anoraks!

 

Edited to add:

Reading Tony Brooks's post a beeper would be handy (in the remote ideally) to tell me when charging rate has reduced to a preselected level so I now when to turn engine off. If a remote is possible then maybe LCD would be better for batt consumption and then could be left on if desired, would make interesting observation.

Edited November 26, 2010 by nb Innisfree

[Québec]

Can't assist on the technical side, sorry, but as a designer - and one who goes around the country talking about the importance of good design - I was struck by Albion's comment about the look and feel of the Smartgauge - although he did say it wouldn't stop him buying one!. The high-spec 'Rolls-Royce' technical functionality and wizardry on the inside ought to be complemented by a similar level of functionality and aesthetics on the outside. It's one reason why high-end car manufacturers spend fortunes on things like getting the sound of the door closing just right, or the smell of the interior, or making sure that switch is in the optimal position. And its the reason why most, if not all things 'Mac' are so successful. Yes, you can buy similar functionality much cheaper...but that's not the point.

[Evo]

A simple display of AMPS and HRS

 

Amps = positive or negative value Hours = Battery Time left at present consumption.

 

No knobs/switches or dials. Hrs displays an infinity symbol if a significant charge is present for a preset period of time.

 

 

Does this exist as a simple unit allready..??? I dont know, its just that thats all my missus wants...she wants to know how hungry an appliance is and how long she's got left. I want to be able to see the effect of my solar panels or wind turbine potentially overcomming daytime consumption.

Edited November 26, 2010 by Evo

[nb Innisfree]

A simple display of AMPS and HRS

 

Amps = positive or negative value Hours = Battery Time left at present consumption.

 

No knobs/switches or dials. Hrs displays an infinity symbol if a significant charge is present for a preset period of time.

 

 

Does this exist as a simple unit allready..??? I dont know, its just that thats all my missus wants...she wants to know how hungry an appliance is and how long she's got left. I want to be able to see the effect of my solar panels or wind turbine potentially overcomming daytime consumption.

 

Our BMV gives us hours to go but as consumption keeps altering so does the readout as it keeps recalculates, waste of time IMO.

[WotEver]

Hours = Battery Time left at present consumption.

I was going to suggest this, but with lots of hysteresis to avoid constantly tumbling numbers. I accept that it would only be an approximation.

 

I'd also like that readout to work in reverse (again, I accept that it would only be approximate) of how long it's going to take to get to 80%/85%/90% (switchable/user setting) charge based on current (sorry) circumstances.

 

Tony

[GUMPY]

A remote LCD display with switch-able back light showing:

 

How much left in house batteries

How many volts house and start

How much current in/out

24/12v dual voltage system

Ability to monitor multiple systems........

 

Having the ability as SG/SB dies to control relays etc works for me but realise that that's not always part of a monitor

 

TBH if I add a shunt ammeter to SG/SB it would do what I think is needed for a single system apart from the remote display.

[Evo]

Are you saying it's a waste of time because it updates too often..??

 

Most of the liveaboards I know just want to know where all the power is going. Is it the lights being on all night or the toaster being used for 5 mins, the fridge, the hairdryer. I get answers like

 

"We stopped using that because we we weren't sure how much juice it was gobbling".

"I put that massive solar panel on - it cost me £700 by the way - and I haven't got a clue how much its helping or even if its doing anytrhing at all".

 

"I swapped to leds's but I dont know what we were using before so I have no idea wether they help or not".

"Whatever I do the telly switches off half way through my favourite program and I have go run the engine"

 

IMO The basic questions are....

1)WHAT POWER AM I USING

2)WHAT IS USING IT

3)HOW LONG WILL MY BATTERIES LAST BEFORE THEY NEED CHARGING

 

With a simple ammeter you can go through your boat switching things on and off and get a very good idea of whats gobbling what.

[charles123]

I would add to thoughts on the presentation of the monitor, in my opinion the smartguage looks a bit home made, if you are going up market it should look quality as well as do quality in its functionallity

 

Charles

[tosher]

I'd be happy with the following :-

 

Remote display.

 

Services Batteries - Amps in/out, Volts, State of charge.

 

Eng & BT batteries - Volts, State of charge.

[nb Innisfree]

Are you saying it's a waste of time because it updates too often..??

Most of the liveaboards I know just want to know where all the power is going. Is it the lights being on all night or the toaster being used for 5 mins, the fridge, the hairdryer. I get answers like

 

"We stopped using that because we we weren't sure how much juice it was gobbling".

"I put that massive solar panel on - it cost me £700 by the way - and I haven't got a clue how much its helping or even if its doing anytrhing at all".

 

"I swapped to leds's but I dont know what we were using before so I have no idea wether they help or not".

"Whatever I do the telly switches off half way through my favourite program and I have go run the engine"

 

IMO The basic questions are....

1)WHAT POWER AM I USING

2)WHAT IS USING IT

3)HOW LONG WILL MY BATTERIES LAST BEFORE THEY NEED CHARGING

 

With a simple ammeter you can go through your boat switching things on and off and get a very good idea of whats gobbling what.

 

Yes, when the fridge cuts in or light or tv switched on it can go from several days to several hours. Looking at a prediction then sitting down for the night with TV on and getting up and switching light on and opening fridge to get milk for tea several times will soon upset that prediction so trying to make an accurate prediction when batts need charging is also like asking how long is a piece of string.

 

I suppose a monitor that can learn how much load different appliances take would be able to tell which ones are on or off, over to you Gibbo?

Edited November 26, 2010 by nb Innisfree

[Justme]

My ideal system would do

 

Every thing the SG does plus

 

one model for 12,24 & 48v systems

have at least 4 separate voltage sensors

(fully independent so can measure any voltage up to 150v dc)

have at least 4 shunt amp inputs

have two amph counters that can count past 1000 both ways (not for the battery soc but for monitoring other inputs / loads)

2 temp sensors (one for bat SOC adjustment & one poss for external temp to control a relay)

more control relays (say 4) with full isolation

(plus add ons to be able to switch mains loads)

have total DC kWh meter recording & a resettable kWh recorder

display for AC V & A & kWh

Load diversion (so when the solar has fully charged the bat it can the turn on other loads) , this could be part of the control relays

Exportable data logging via USB (not live data only but downloaded say monthly or yearly) or removable memory chip or better yet via WiFi / Cat5 with no dongle needed.

Programmable vis PC link.

 

 

Down side is I could not afford that.

 

I think that will do for starters.

 

Most of the above I have put together using bits & bobs & features on other kit.

[mayalld]

This may open up a can of worms.

 

I'm just coming to the end of the design and debugging of a rather complex battery monitor (however not the sort that is applicable to the average boat owner as it's really far too complex and expensive plus it requires the use of further external devices - for instance it doesn't even have a display) that incorporates more or less every possible feature that man could devise.

 

We've been discussing transferring parts of that design to a new standalone battery monitor and my experience is that actually asking the sorts of people who would be using it, "what do you want?", usually scores dividends and often a few surprises. Many manufacturers seem to miss this stage with the result that they simply produce yet another version of something that has been available for 25 years (the same device with a light in a different place).

 

Some of you use amp hour counters, some of you use SmartGauges, some use voltmeters, some use ammeters, some use a combination, some use nothing. Some are happy with what they have, others less so, some have tried one, not liked it and moved onto something else. None of them are perfect (battery monitoring is not, depsite its apparent simplicity, an exact science) but different ones suit different people. Much of it comes down to the owner's knowledge and experience in what they can actually make work for them.

 

Given a blank sheet, what would you want of a battery monitor? What features would you demand? What would you wish for? What would be a "like" but not a demand? What would be an "absolute must"?

 

Are you currently using something that's almost right for you but you wish it also had such and such a feature?

 

Is there something in particular that stopped a certain device from working for you?

 

Remember that every additional feature will cost money and some people even squeal at the cost of a voltmeter let alone something costing hundreds of pounds. However this device is, at present, aiming to be the Rolls Royce of battery monitors. The budget market is already pretty well covered. Whilst some people avoid expensive equipment, there are just as many who love it.

 

As a boater, and having designed several in the past, I think I have some idea of the overall ideal device but input will be gratefully received and noted even if I disagree with it. The device wont be for me therefore my opinion is worthless.

 

The design process on this sort of device is very long so it will be some time before it sees the light of day but if anyone (or more than one) came up with a brilliant idea I'm sure I could pull some strings and get you allocated as a "beta tester" (which means you'd get one for free ).

 

PS. I have just spoken to "management" and this product has now been given the green light. I start the design when the current two are finished which should be about the end of January.

 

OK, information that I would like a really whizzy battery monitor to tell me;

• Is my present current draw too deep for the bank to handle (alarm)
• What proportion of original capacity remains
• How long until they need replacing
• Am I treating my battery bank well, or abusing it (RAG indicators)

[Sunset Rising]

 

IMO The basic questions are....

1)WHAT POWER AM I USING

2)WHAT IS USING IT

3)HOW LONG WILL MY BATTERIES LAST BEFORE THEY NEED CHARGING

 

 

Yes, those wold be the questions, but I accept that 3 might not be practical

 

 

 

But hark, what is that strange noise I hear ? Its wierd, a bit like rumbling, or teeth grinding, Oh I know, its the sound of smartguage sales tumbling while everyone waits for the einstein guage to come out.

[WotEver]

• Am I treating my battery bank well, or abusing it (RAG indicators)

I like that one!

 

Great idea.

 

Tony

[MoominPapa]

My ideal would be something that has "how full is my battery" functionality of the smartguage, combined with a reset-able amp-hour counter. I accept that integrating current over long periods to get a "battery fullness" is a mugs game, but being able to answer the question "how many amp-hours did we use yesterday" is very useful. I'd want at least a current read out on the domestic battery, and preferably the ability to put shunts in the engine battery line and the alternator output line to measure current there. Make the number of shunts a round four and you could use one for solar panel output too. The solar one should have a amp-hour function for bragging about the quantity of free energy captured. Voltage read-out on both battery banks is a given.

 

Form factor should be a round instrument, same size as oil pressure/temp gauges (52mm dia?). Main display should be LED/vacuum flouro with idle display blanking. There should be enough buttons to be able to cycle through all the information displays easily, but I'd put a USB port on the back and/or front to allow setup to be done via a software application - I hate massively overloaded buttons for that sort of stuff. The USB port should make data available for logging, and the API should be public and stable to allow free software geeks like me to do fun things with it.

 

MP.

[Iain_S]

(snip)

Given a blank sheet, what would you want of a battery monitor? What features would you demand? What would you wish for? What would be a "like" but not a demand? What would be an "absolute must"?

(snip)

 

The current Smartgauge works well, but could do with a measurement of actual battery bank capacity, and possibly condiion. This would require a current input via a shunt, and a timer to calculate Amp hours out, which could then compare with % state of charge to give total or remaining capacity. It might also be possible to obtain some measure of condition using the methodology of this paper

 

A 48V version would also be nice......

 

Iain

[nb Innisfree]

Built in broadband and space invaders + a paint job that changes colour at different angles like you get with some cars

[WotEver]

this paper

Interesting reading. Thanks, Iain.

 

Tony

[Old Son]

I would like dual voltage in one unit so I can check my starter battery. I like the idea of a remote so I can check how things are when I am watching the box of a night. It would be handy if I could switch between volts and amps and it does feel a bit cheap. Overall the smartgauge is a great invention, well done Gibbo!!!

[Keeping Up]

Rather like one or two others on here, I am very keen on analogue representations. I have moving-needle ammeter and voltmeter on my dashboard, and the pattern of their movements tells me a great deal. For example if the charge current and the voltage are for some reason swinging up and down, it is useful to see at a glance whether they are rising together or one is rising while the other is falling - and a load of whirring digits doesn't help much in that respect.

 

I accept that a good analogue representation on a digital gauge is something of a challenge: a bar of LEDs or displayed dots probably won't do it. One way that I have seen, is to modulate the brightness or colour of an LED in an analogue fashion. An LED showing the battery voltage and another one showing current could present that picture of what is going on, rather than just the mathematics of it.

 

Clearly anything LED based would need to be switched on only when required.