Smartgauge and lithium

[blackrose]

A neighbour of mine needs a battery monitor and I suggested a Smartgauge as it's simple to fit and easy to use and understand. 

 

However at some point she wants to get lithium batteries installed and I'm not sure if the Smartgauge can be configured for lithium? 

 

This is from the manual. 

[Rod Stewart]

https://balmar.net/products/smartgauge-battery-monitor/

 

Quote

The Smartgauge^TM Battery Monitor works with Standard Flooded, Deep Cycle Flooded, Sealed Maintenance Free, Gel Cell, AGM and Lead Acid Hybrid batteries. Smartgauge^TM does not monitor Lithium Ion batteries. Smartgauge^TM 

 

They could always go for a victron smartshunt without the associated gauge.Its one less thing to install if one has a smartphone.

[GUMPY]

14 minutes ago, blackrose said:

A neighbour of mine needs a battery monitor and I suggested a Smartgauge as it's simple to fit and easy to use and understand. 

 

However at some point she wants to get lithium batteries installed and I'm not sure if the Smartgauge can be configured for lithium? 

 

This is from the manual. 

It doesn't.

Victron Smart Shunt, using an app on your phone to read it,  is pretty accurate with Lithium. However as with LA it needs to be set up correctly.

 

Edited Wednesday at 20:17 by GUMPY

[blackrose]

Ok thanks Both

[Rod Stewart]

Not cheap, but there is the SG200.

 

https://balmar.net/application/marine/battery-monitors/

[dmr]

Smartgage can't do lithium, LiFePo was not common, maybe not even available, when the SG was designed. Also the lithium voltage curve and other behaviours are not compatiblw with the "simple" voltage only method that SG uses.

 

Many lithiums will have their own indication of state of charge that can be displayed on a smartphone, this comes from their internal battery management system, but not as easy and convenient as the Smartgage. We likely go lithium in a couple of weeks and I will miss the Smartgage.

[nicknorman]

5 minutes ago, dmr said:

Smartgage can't do lithium, LiFePo was not common, maybe not even available, when the SG was designed. Also the lithium voltage curve and other behaviours are not compatiblw with the "simple" voltage only method that SG uses.

 

Many lithiums will have their own indication of state of charge that can be displayed on a smartphone, this comes from their internal battery management system, but not as easy and convenient as the Smartgage. We likely go lithium in a couple of weeks and I will miss the Smartgage.

My experience of SoC from LiFePO4 batteries is limited to the Fogstar Drift in my caravan, but it's not great at all. I use a BMV712 although of course a smartshunt would effectively be the same thing if you have a smartphone. With a high charge efficiency of around 99% (no gassing to absorb electricity!) the BMV on the boat doesn't drift much, I sync it to 100% every couple of weeks but it is rarely much out. And anyway, with Li the SoC is of less importance

[dmr]

SoC IS still important, don't want the lights to go out unexpectedly 😀. There is no need to get to 100% periodically like with lead acid, but then Smartgage was not good at the 100% thing..

 

An article hidden away on the Fogstar website does say the BMS state of charge is not too good, the "shunt" in the BMS is nothing like a proper shunt. Also it suggests that the BMS fails to see small currents (0.7 amp or less?) so medium loads might be ok but longer term light loads will mess things up.

[nicknorman]

38 minutes ago, dmr said:

SoC IS still important, don't want the lights to go out unexpectedly 😀. There is no need to get to 100% periodically like with lead acid, but then Smartgage was not good at the 100% thing..

 

An article hidden away on the Fogstar website does say the BMS state of charge is not too good, the "shunt" in the BMS is nothing like a proper shunt. Also it suggests that the BMS fails to see small currents (0.7 amp or less?) so medium loads might be ok but longer term light loads will mess things up.

 

SoC is important, but less important than for LA. I say this because with LA one gets all twitchy if the SoC gets near 50% and if it were found to be 30%, the end of the world would be nigh. But with Li, if the SoC is 20% and I want to put on the 2kw electric kettle, it's no problem. This does take some getting used to!

Really, in terms of the lights going out, unless you put the electric kettle on at a really bad moment, you will be fine so long as the light load voltage is above 13v. Once it starts going below 13v you are heading for lights out in a while, but you probably still have at least 10%.

It is still necessary to get to 100% periodically but only for the benefit of the amp-hour counting SoC gauge.

Yes, amongst its other failings, the Fogstar BMS doesn't notice small currents.

 

I would ditch the Smartgauge and get a Victron BMV712 or a SmartShunt.

Edited Wednesday at 22:00 by nicknorman

[dmr]

I decided a while ago to go lithium at some stage so am much more relaxed about the Trojans, I don't start to panic till they get down to about 35%, but I have never really believed in the 50% rule 😀.

Have had a BMV712 for a while now, its good, and very interesting watching how it compares with, and diverges from, the Smartgage. Have the Arco Zeus too so the move to lithium when it arrives should not be too traumatic, though lifting a 60kg lump through the back cabin and into the battery box behind the engine might need a bit of planning.

[GUMPY]

Problem with the Fogstar SOC is that it doesn't register small discharges under about an amp or two. If you have  small discharges as I do (the monitor system draws about 0.7amp) having been on for say  48hrs that's 33Ah out of the battery. The Fogstar is still reading almost 100% whereas the smart shunt is reading 68% 

I know which is correct.

[nicknorman]

21 minutes ago, dmr said:

I decided a while ago to go lithium at some stage so am much more relaxed about the Trojans, I don't start to panic till they get down to about 35%, but I have never really believed in the 50% rule 😀.

Have had a BMV712 for a while now, its good, and very interesting watching how it compares with, and diverges from, the Smartgage. Have the Arco Zeus too so the move to lithium when it arrives should not be too traumatic, though lifting a 60kg lump through the back cabin and into the battery box behind the engine might need a bit of planning.

60kg? Must be the 560Ah Drift Pro. That should keep you going for a bit. And outlive you! Amazing how prices have come down, my 600Ah of bare cells from China was £1800 about 3 years ago, and I thought that was cheap. The 560Ah Drift Pro at £1050 is great value! What will you do with all that energy?!

[dmr]

Lithiums are really good value now. We have/had 750amp hour of Trojans so this is not a big step forward. We use a bit over 100amp-hour per day and it would be nice to sometimes go 3 or 4 days between engine runs, so 560 lithium is not huge.   I have a half plan to build a second DIY version of the Fogstar pro by fitting the cells into the limited battery box space, but maybe 1120amp hour is over the top😀?

Might want to ditch the fridge freezer and get separate fridge and freezer, and Gillie dreams of an air fryer but thats a step too far.

[nicknorman]

8 minutes ago, dmr said:

Lithiums are really good value now. We have/had 750amp hour of Trojans so this is not a big step forward. We use a bit over 100amp-hour per day and it would be nice to sometimes go 3 or 4 days between engine runs, so 560 lithium is not huge.   I have a half plan to build a second DIY version of the Fogstar pro by fitting the cells into the limited battery box space, but maybe 1120amp hour is over the top😀?

Might want to ditch the fridge freezer and get separate fridge and freezer, and Gillie dreams of an air fryer but thats a step too far.

 

Air fryers are great, especially on a boat. We barely use any gas these days and it doesn't overheat the inside of the boat in summer (unlike the gas oven). Next time I see Gillie I will point all this out to her...😝

I must say i thought our 600Ah would be over the top (replacing 450Ah of Trojans), but with most of the cooking done by battery power these days, I would now describe it as "adequate".

Edited Wednesday at 22:54 by nicknorman

[jonathanA]

I recently fitted a frogspawn 460 for a someone. I lifted it into position without too much difficulty, deffo a lot lighter then the equivalent La would have been...  

 

Worth remembering the bms limits the max current to 250A on these bigger single batts. 

 

For him the game changer is the much reduced recharge time  as he is off grid so needs to run a generator 

[dmr]

Life changes as we get older, we now have a rather lovely mooring to spend much of the winter, so the days of doing long hours boating most days (and very full bateries) are over (though we still do some pretty serious boating in the summer) plus global warming really is here and I want to do my little bit to help. For us having a lot of battery and then a higher load engine run every few days is the way to go. The mooring is lovely but there are some big hills so winter solar is even worse than usual, the sun sets at 2pm 😀.

 

I might even replace the Travelpower with a 48volt system with its own lithium bank so that we can run the washing machine sometimes without needing to run the engine.

8 minutes ago, jonathanA said:

I recently fitted a frogspawn 460 for a someone. I lifted it into position without too much difficulty, deffo a lot lighter then the equivalent La would have been...  

 

Worth remembering the bms limits the max current to 250A on these bigger single batts. 

 

For him the game changer is the much reduced recharge time  as he is off grid so needs to run a generator 

 

But a lithium comes as one big lump while the Trojans split into (just) managable 30kg lumps.

I am quite happy to do a very long engine run once every few days so charging at 100amps or so will be fine, its the long light load running to get the last few amp-hours into lead acids that needs to go.

[blackrose]

I have a Smartgauge and a BEP DC meter which uses a shunt. I mainly use that one to see amps in/out and to look at tail current to know when to stop charging.

 

Will a shunt-type battery monitor work with lithium batteries? It's probably at least 18 years old. 

 

INST-600-DCM V3.2.doc

 

[Rod Stewart]

4 minutes ago, blackrose said:

I have a Smartgauge and a BEP DC meter which uses a shunt. I mainly use that one to see amps in/out and to look at tail current to know when to stop charging.

 

Will a shunt-type battery monitor work with lithium batteries? It's probably at least 18 years old. 

 

INST-600-DCM V3.2.doc

 

Yes, as long as you can change the settings, which it looks like you can, it should be fine.

[blackrose]

16 minutes ago, Rod Stewart said:

Yes, as long as you can change the settings, which it looks like you can, it should be fine.

 

Thanks. I don't remember setting a battery type on this monitor and I can't see any settings for that. I ignore the SOC function of this monitor because it's meaningless unless you continuously calibrate it. I just use it for voltage and amps, so that's going to work with any 12v battery type isn't it?

[Rod Stewart]

22 minutes ago, blackrose said:

 

Thanks. I don't remember setting a battery type on this monitor and I can't see any settings for that. I ignore the SOC function of this monitor because it's meaningless unless you continuously calibrate it. I just use it for voltage and amps, so that's going to work with any 12v battery type isn't it?

You should change the charge efficiency and peukert exponent to reflect the Lithium chemistry at the very least, but it should work the same way as it does for your lead acid set up, except:

 

I can't see a 'charged voltage' setting in your instructions, so it may be programmed only for lead acid type batteries. Not so important if you wont use the SOC function.

Edited Thursday at 09:33 by Rod Stewart

[nicknorman]

11 hours ago, dmr said:

Life changes as we get older, we now have a rather lovely mooring to spend much of the winter, so the days of doing long hours boating most days (and very full bateries) are over (though we still do some pretty serious boating in the summer) plus global warming really is here and I want to do my little bit to help. For us having a lot of battery and then a higher load engine run every few days is the way to go. The mooring is lovely but there are some big hills so winter solar is even worse than usual, the sun sets at 2pm 😀.

 

I might even replace the Travelpower with a 48volt system with its own lithium bank so that we can run the washing machine sometimes without needing to run the engine.

 

You won’t need to run the engine to run the washing machine, assuming you have an inverter that can cover the load / the heating element isn’t too huge. The heating element isn’t on for that long and after that, it doesn’t use much energy to turn the drum and operate water valves and pumps. I suppose if you use the dryer function or have a tumble drier that might be slightly different.

 

I would suggest getting (or using) a decent battery charger so you can use the TP to supplement the alternator. 200A charge current would be so much better than 100A! I got the 40A Fogstar charger for the caravan, £100. It is quite good. The fan is rather noisy but if you are running the engine anyway… so for £100 you would add 40% to the charge current. 

[blackrose]

2 hours ago, Rod Stewart said:

You should change the charge efficiency and peukert exponent to reflect the Lithium chemistry at the very least, but it should work the same way as it does for your lead acid set up, except:

 

I can't see a 'charged voltage' setting in your instructions, so it may be programmed only for lead acid type batteries. Not so important if you wont use the SOC function.

 

Thanks again.

 

On those fogstar drift batteries. Is there any difference between installing 1 x 560ah and 2 x 280ah? Apart from the price?

 

Just thinking about the 50kg weight of that 560ah monster

Edited Thursday at 12:01 by blackrose

[GUMPY]

How much do the Trojans weigh?  

You will only have to move it once.

A youngun like you should easily manage it🤔

[Tony Brooks]

12 minutes ago, blackrose said:

 

Thanks again.

 

On those fogstar drift batteries. Is there any difference between installing 1 x 560ah and 2 x 280ah? Apart from the price?

 

Just thinking about the 50kg weight of that 560ah monster

 

Is there not something that may be problematical for the BMS's when you parallel batteries unless they can talk to each other.

[dmr]

1 hour ago, nicknorman said:

You won’t need to run the engine to run the washing machine, assuming you have an inverter that can cover the load / the heating element isn’t too huge. The heating element isn’t on for that long and after that, it doesn’t use much energy to turn the drum and operate water valves and pumps. I suppose if you use the dryer function or have a tumble drier that might be slightly different.

 

I would suggest getting (or using) a decent battery charger so you can use the TP to supplement the alternator. 200A charge current would be so much better than 100A! I got the 40A Fogstar charger for the caravan, £100. It is quite good. The fan is rather noisy but if you are running the engine anyway… so for £100 you would add 40% to the charge current. 

 

Our boat is a funny miixture of low tech and almost high tech, done in part by the previous owners and continued/evolved by us. Its a sort of long term off grid liveaboard without too many mod cons. Travelpower is always on so we have mains when the engine runs, mostly just for the washing machine and breadmaker, and imersion heater to put a bit of load on the engine. The inverter is quite small, a cheapo 1000w unit. This is not used much. I wanted it to enable soldering repairs etc without running the engine, but it gets used for a little electric whisk too from time to time. I upgraded the battery cabling from 25mm to a mix of 35 and 50mm as the intention is to be able to go a few days on light electrical loads rather than to drive anything big. Its rare to see more than about 12 amps going out of the batteries.

 

Charging is currently via a 100 amp alternator that can only do about 50 to 60amps without getting too hot, supplemented by 25 amps from the starter alternator via the new Victron Orion DC-DC, plus a 30 amp Victron charger from the TravelPower. The Victron charger does not perform well as it does not sense battery voltage so the various cable volt drops force it to shut down much too soon. I might be able to improve that.  ..... and a Victron solar controller from our tiny 160amp solar panel.  I am tempted by replacing the 100amp alternator with a 175amp like yours but this is not trivial as it involves re-routing some of the engine cooling system, and will still only give us 80 amps as Im stuck with a single V belt (or some serious engineering)

 

I don't want a bigger inverter as that will involve a lot of new cabling, and I don't like the idea of big inverters from 12 volts, especially after we saw a boat fire caused by a washing machine running from an inverter. I am increasingly thinking that a second battery bank at 48volts and a dedicated inverter  is the way to go, this will replace the Travelpower and allow some washing machine use, and maybe even immersion heater, without running the engine. Finding a 48 volt alternator is the difficult bit.  I want to get a bit of hands on experience with the 12volt lithium and then will look seriously at the 48volt bank.

13 minutes ago, GUMPY said:

How much do the Trojans weigh?  

You will only have to move it once.

A youngun like you should easily manage it🤔

 

There are some proper young'uns (<<60) near where we moor so they can help.