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10 hours ago, AWETHEAYET said:

Bought the boat and replaced the 120 va invertor with a victron 3000 multyplus new bat monitor and colour controller, seller replaced bats with 3 x 120aH maintenance free and a 90 ah starter.

I have set the BM to 360 and left everthing else to factory setting. What else should I consider to change within the system/ programing to give the batteries a "good life" while maintaing electricity to the boat?

HTATBO as a new toy on her phone that instructs me to start the engine, makes a change from putting the kettle on :)

Depends upon exactly what battery monitor but in general it will be fine if you ignore any reading that takes account of how many amp hours the monitor thinks has gone INTO the battery. Those scales are likely to tell larger and larger lies over time and say the batteries are fully charged when they are not. Those scales include % charges, Ah or time left and so on.You can rely upon the Volts, Amps and amp hours used to be accurate so:

 

Charge at least once a week until the charging current is around 1 to 2% of battery capacity so in your case around 7 to 8 amps and has stopped falling for half an hour or so.

 

Use rested voltage with no load running to infer state of charge/when its vital to recharge.

 

After fully charging the batteries zero the Ah out reading and wait until the next day. Read the Ah out and the inferred state of charge from the rested voltage and use those to estimate the present battery capacity (it won't be 360Ah). Then fully charge the batteries and recalibrate the meter, if not done before set the tail current back from the factory set 4% or so to 1% and input the new capacity. Then as long as you fully charge the batteries once a week and keep the capacity updated those lying scales will not be far out.

 

Edited to add:

 

PS the first paragraph includes when the device phones your wife if its linked to the battery monitor, unless you follow the instructions re resetting the tail current, regularly fully charging and calibrating the meter it will almost certainly phone too late so the batteries are far more discharged than the monitor says they are. If the device is linked to voltage it will be better but may tell you to start the engine early (a good thing) because any load will depress the voltage and suggest the batteries are more discharged than they are.

Edited by Tony Brooks
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17 minutes ago, ditchcrawler said:

A chap posted on Facebook he has just bought 8 110Ah batteries to replace the knackered ones, I pointed out if he takes them down to 50% he probably wont be able to recharge them in a day.

Yup. Firstly do a power audit, secondly work out how you will generate that. Go backwards and forwards with those two until they balance. Lastly, buy enough batteries. 

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4 hours ago, ditchcrawler said:

A chap posted on Facebook he has just bought 8 110Ah batteries to replace the knackered ones, I pointed out if he takes them down to 50% he probably wont be able to recharge them in a day.

 

Indeed, when I was working I often witnessed batteries taken down to 0% and it always took the best part of 24 hours to fully recharge them.

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12 hours ago, Tony Brooks said:

Depends upon exactly what battery monitor but in general it will be fine if you ignore any reading that takes account of how many amp hours the monitor thinks has gone INTO the battery. Those scales are likely to tell larger and larger lies over time and say the batteries are fully charged when they are not. Those scales include % charges, Ah or time left and so on.You can rely upon the Volts, Amps and amp hours used to be accurate so:

 

Charge at least once a week until the charging current is around 1 to 2% of battery capacity so in your case around 7 to 8 amps and has stopped falling for half an hour or so.

 

Use rested voltage with no load running to infer state of charge/when its vital to recharge.

 

After fully charging the batteries zero the Ah out reading and wait until the next day. Read the Ah out and the inferred state of charge from the rested voltage and use those to estimate the present battery capacity (it won't be 360Ah). Then fully charge the batteries and recalibrate the meter, if not done before set the tail current back from the factory set 4% or so to 1% and input the new capacity. Then as long as you fully charge the batteries once a week and keep the capacity updated those lying scales will not be far out.

 

Edited to add:

 

PS the first paragraph includes when the device phones your wife if its linked to the battery monitor, unless you follow the instructions re resetting the tail current, regularly fully charging and calibrating the meter it will almost certainly phone too late so the batteries are far more discharged than the monitor says they are. If the device is linked to voltage it will be better but may tell you to start the engine early (a good thing) because any load will depress the voltage and suggest the batteries are more discharged than they are.

Thanks Tony

Great advice as normal. At the moment I will be on shore power for a while so batteries will be fully charged. I have quite a few "rust" oppertunities to keep me entertained for a while.

I also want to turn my thoughts to why I need to run the engine for hot water and the gas boiler for heating and not vice versa.

Edited by AWETHEAYET
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12 hours ago, AWETHEAYET said:

I also want to turn my thoughts to why I need to run the engine for hot water and the gas boiler for heating and not vice versa.

 

Check how many coils your calorifier has.

 

It could be a single coil calorifier, with the coil connected to the engine, rather than a twin coil calorifier with the engine on one coil and the gas boiler on the other.

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Just now, cuthound said:

 

Check how many coils your calorifier has.

 

It could be a single coil calorifier, with the coil connected to the engine, rather than a twin coil calorifier with the engine on one coil and the gas boiler on the other.

That means usually four pipes connections on a single coil calorifier and six on a twin coil one. If it is  a twin coil one then look for a valve on the pipes that allows the hot water from the boiler to be directed to heating, hot water or both. There may or may not be one. Again if its a twin coil one then an airlock in the boiler coil might stop it heating, especially if the gas boiler is an upright Alde or a very old Ellis.

12 hours ago, AWETHEAYET said:

Thanks Tony

Great advice as normal. At the moment I will be on shore power for a while so batteries will be fully charged. I have quite a few "rust" oppertunities to keep me entertained for a while.

I also want to turn my thoughts to why I need to run the engine for hot water and the gas boiler for heating and not vice versa.

 

But not if you are living aboard and the charger does its adaptive charging thing. That is unless once a week you turn it off and on again when it drops to float a few times.

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11 minutes ago, Tony Brooks said:

But not if you are living aboard and the charger does its adaptive charging thing. That is unless once a week you turn it off and on again when it drops to float a few times.

Having lived with various chargers that have adaptive charging once the batteries are at 100%, usually achieved by cycling the charger once, and provided the charger is left on 24/7 it is not necessary to recycle it every week, the charger should keep the batteries at 100% unless you are using very large loads greater than the charger output.

 

13.8v will charge a LA battery it just takes a very long time. ;)

 

 

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1 minute ago, Loddon said:

Having lived with various chargers that have adaptive charging once the batteries are at 100%, usually achieved by cycling the charger once, and provided the charger is left on 24/7 it is not necessary to recycle it every week, the charger should keep the batteries at 100% unless you are using very large loads greater than the charger output.

 

13.8v will charge a LA battery it just takes a very long time. ;)

 

 

Agreed but that is what we do not know. His loads or his charge output, we can guess but not know. I said once a week to be sure he would not be risking leaving his batteries partially discharged. Especially as he seems intend on buying more expensive batteries.

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On 03/10/2020 at 11:05, ditchcrawler said:

A chap posted on Facebook he has just bought 8 110Ah batteries to replace the knackered ones, I pointed out if he takes them down to 50% he probably wont be able to recharge them in a day.

We have about 700Ah and it charges in a day without too much fuss. The alternators can deliver over 100amp continuously  (though a bit more would be good) and the Adverc keeps them going flat out right to the end of the bulk phase. If the facebook boat can deliver a continuous 150amps it should be fine.

 

With 700Ah we only need to run the engine every other day, and only every third day if the sun makes a bit of solar or if we are out all day. Big battery banks and modest consumption are good, I would not want to be doing long engine runs every day. 

 

..............Dave

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1 hour ago, dmr said:

We have about 700Ah and it charges in a day without too much fuss. The alternators can deliver over 100amp continuously  (though a bit more would be good) and the Adverc keeps them going flat out right to the end of the bulk phase.

But the absorption phase will still take several hours.  At 90% SoC 700Ah of batteries will only take around 70A, whatever boxes of tricks you might have. Then at 91% 63A, at 92% 56A etc.

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3 hours ago, WotEver said:

But the absorption phase will still take several hours.  At 90% SoC 700Ah of batteries will only take around 70A, whatever boxes of tricks you might have. Then at 91% 63A, at 92% 56A etc.

Yes, very roughly the duration of the absorption phase is fixed by battery characteristic, not by bank capacity, so a big bank will only extend the bulk phase. As long as the available alternator current is increased pro-rata with the bank capacity the total charge time is unchanged. The problems occur when people increase the battery bank without also increasing the available charge current.

In a full boaters day (10 till 5 ?) I think I can do a pretty full charge and maybe even a bit of equalisation, though I never get down to 1%, maybe 2-1/2% if I am lucky, and I am happy to start equalisation a lot sooner than many say is wise.

 

...............Dave

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  • 2 weeks later...

Good post Tony!
This is 'must know' info for anyone boating, or new to boating.
Excellent summary in case there are others out there who just aren't getting to 14V on alternator charging and thus risking undercharging. There must be a load of boats from 2000-20005 that suffer the same problem.I have a boat, mostly we used it for fishing purposes. We have boats and fishing equipment, fishing lure, etc. I replace my boat engine two times but its speed is very slow when I try to fast it releases a black smoke my friend told me that engine was out of order to change it with an alternate Model.

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59 minutes ago, republicscented said:

Good post Tony!
This is 'must know' info for anyone boating, or new to boating.
Excellent summary in case there are others out there who just aren't getting to 14V on alternator charging and thus risking undercharging. There must be a load of boats from 2000-20005 that suffer the same problem.I have a boat, mostly we used it for fishing purposes. We have boats and fishing equipment, fishing lure, etc. I replace my boat engine two times but its speed is very slow when I try to fast it releases a black smoke my friend told me that engine was out of order to change it with an alternate Model.

Sounds as if you have an overlarge prop for the engine to me. Black smoke = overloading on a diesel and on aboat that all too often means oversized prop.

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On 03/10/2020 at 08:30, Tony Brooks said:

 

After fully charging the batteries zero the Ah out reading and wait until the next day. Read the Ah out and the inferred state of charge from the rested voltage and use those to estimate the present battery capacity (it won't be 360Ah). Then fully charge the batteries and recalibrate the meter, if not done before set the tail current back from the factory set 4% or so to 1% and input the new capacity. Then as long as you fully charge the batteries once a week and keep the capacity updated those lying scales will not be far out.

 

 

rookie question:  what device do you recommend for taking those readings?

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19 minutes ago, Wittenham said:

rookie question:  what device do you recommend for taking those readings?

There are several "battery monitors" by the major marine electronic suppliers but all I ever used was a reasonably accurate voltmeter and ammeter. As I assessed my battery capacity by how deep it discharged overnight I had no need for an amp hour out counter. I am sure you will get recommendations from those who use such meters. Balamar supply one that seems to be far more accurate than the normal offerings but it really costs.

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  • 4 weeks later...
On 20/10/2020 at 17:52, Tony Brooks said:

There are several "battery monitors" by the major marine electronic suppliers but all I ever used was a reasonably accurate voltmeter and ammeter. As I assessed my battery capacity by how deep it discharged overnight I had no need for an amp hour out counter. I am sure you will get recommendations from those who use such meters. Balamar supply one that seems to be far more accurate than the normal offerings but it really costs.

200 quid + VAT...

 

https://rjsmarine.co.uk/product/balmar-sg200-battery-monitor/

https://www.es-store.co.uk/product_details.php?product=BAL-BM-ACC-SG200&description=Balmar-SG200-Battery-Monitor-Kit-&manufacturer=Balmar-&mf=49

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40 minutes ago, IanD said:

I have been reliably informed that the SG200 does not use the same algorithm as smartgauge despite what the blurb says. It apparently works in a similar way to the NASA BM2 which is considerably cheaper at £135.

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1 hour ago, Loddon said:

I have been reliably informed that the SG200 does not use the same algorithm as smartgauge despite what the blurb says. It apparently works in a similar way to the NASA BM2 which is considerably cheaper at £135.

The Balmar blurb says that it is an improvement on the Smartgauge (because it uses current measurement as well as voltage), not that it uses the same algorithm -- and in the end whether it uses the same algorithm or a different one doesn't matter, what matters is the results, and they seem excellent:

 

https://marinehowto.com/balmar-sg200-self-learning-battery-monitor/

 

Also note: "The Balmar SG200 is a self-learning battery monitor which was 100% developed in-house by CDI/Balmar"

 

The NASA BM2 is a lot cheaper and has been around a lot longer, but there doesn't seem to be much feedback about it from either users or review sites (including test results), and I suspect from the description that it's rather less sophisticated than the Balmar -- for example, it doesn't track the actual battery capacity (and how it reduces as the battery ages), it only uses the nominal Ah value you enter. It's also lead-acid only and 12V only, which is fine if that's what you have.

 

Either of them is still likely to be a better at doing its job than the voltage-only Smartgauge, which in turn is better than not having a BMS at all. Of course if you know what you're doing and are willing to use a DVM/clamp meter to make measurements (including in the middle of the night...) and have enough knowledge to interpret the results correctly you can save some money by not installing any of them, but this level of bother/skill/attention isn't what most boaters can do or want to do, they just want something that reliably tells them how healthy their batteries are and how well charged they are.

 

From what I can see the Balmar is the best at doing this, but it isn't cheap. However if it extends your battery life then it might be a bargain in the long run, especially with an expensive battery bank.

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40 minutes ago, IanD said:

The Balmar blurb says that it is an improvement on the Smartgauge (because it uses current measurement as well as voltage), not that it uses the same algorithm -- and in the end whether it uses the same algorithm or a different one doesn't matter, what matters is the results, and they seem excellent:

You have used, tested and evaluated the SG200 then?

Whilst they don't actually say its the same algorithm the do say Smartgauge tm which implies it is.

Personally I will stick with my Smartgauge  having had one since the fist issue I know its capabilities.

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2 hours ago, IanD said:

The Balmar blurb says that it is an improvement on the Smartgauge (because it uses current measurement as well as voltage), not that it uses the same algorithm -- and in the end whether it uses the same algorithm or a different one doesn't matter, what matters is the results, and they seem excellent:

 

https://marinehowto.com/balmar-sg200-self-learning-battery-monitor/

 

Also note: "The Balmar SG200 is a self-learning battery monitor which was 100% developed in-house by CDI/Balmar"

 

The NASA BM2 is a lot cheaper and has been around a lot longer, but there doesn't seem to be much feedback about it from either users or review sites (including test results), and I suspect from the description that it's rather less sophisticated than the Balmar -- for example, it doesn't track the actual battery capacity (and how it reduces as the battery ages), it only uses the nominal Ah value you enter. It's also lead-acid only and 12V only, which is fine if that's what you have.

 

Either of them is still likely to be a better at doing its job than the voltage-only Smartgauge, which in turn is better than not having a BMS at all. Of course if you know what you're doing and are willing to use a DVM/clamp meter to make measurements (including in the middle of the night...) and have enough knowledge to interpret the results correctly you can save some money by not installing any of them, but this level of bother/skill/attention isn't what most boaters can do or want to do, they just want something that reliably tells them how healthy their batteries are and how well charged they are.

 

From what I can see the Balmar is the best at doing this, but it isn't cheap. However if it extends your battery life then it might be a bargain in the long run, especially with an expensive battery bank.

 

The Smartgage is the only instrument on the boat that I look at many times every day. It works, its worked for many years, a few things confuse it for a short time but it always sorts itself out. I really can't see how a BM2 can get even close to what the Smartgage does.

Right now the odds are stacking up against us, no solar, dark nights giving higher electric consumption, lower temperature taking away battery capacity, and the Trojans are now over 5 and a half years old. An amp hour counter would be really useful, I must get one, but the Smartgage is essential.

 

................Dave

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59 minutes ago, dmr said:

 

The Smartgage is the only instrument on the boat that I look at many times every day. It works, its worked for many years, a few things confuse it for a short time but it always sorts itself out. I really can't see how a BM2 can get even close to what the Smartgage does.

Right now the odds are stacking up against us, no solar, dark nights giving higher electric consumption, lower temperature taking away battery capacity, and the Trojans are now over 5 and a half years old. An amp hour counter would be really useful, I must get one, but the Smartgage is essential.

 

................Dave

:) and I would beg to differ. I bought a BM2 first and like the AH counting and the instantaneous Amps flowing, but the SOC is useless. So I bought a Smartgauge.

 

Looked great, so I trusted it to tell me when the batteries were full - big mistake.

 

Smartgauge is admittedly not accurate when charging and not accurate when discharging until below 80%, so its only value, (to me) is to tell me when to start charging.  I can see that on the BM2 by either voltage or Ah used.

 

Its only redeeming feature is that, armed with info from the BM2, I can calculate actual capacity.

 

I have since got a lithium bank and a Victron BMV712.

 

If starting out again, with hindsight, my advice would be to get the Victron but, if money is tight, get the NASA.

Edited by Richard10002
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3 minutes ago, Richard10002 said:

:) and I would beg to differ. I bought a BM2 first and like the AH counting and the instantaneous Amps flowing, but the SOC is useless. So I bought a Smartgauge.

 

Looked great, so I trusted it to tell me when the batteries were full - big mistake.

 

Smartgauge is admittedly not accurate when charging and not accurate when discharging until below 80%, so its only value, (to me) is to tell me when to start charging.  I can see that on the BM2 by either voltage or Ah used.

 

Its only redeeming feature is that, armed with info from the BM2, I can calculate actual capacity.

 

I have since got a lithium bank and a Victron BMV712.

 

If starting out again, with hindsight, my a limitationdvice would be to get the Victron but, if money is tight, get the NASA.

Its well known that Smartgage is not accurate during charging, its little better than a guess, though actually quite a good guess. !00% is a good "daily charge" but not the full "weekly or monthly charge".

I have not heard of this 80% limitation. After a charge Smartgage takes a while to sort itself out, thats surface charge, and those who advocate using a simple voltmeter have exactly the same problem, its just physics. The Balmar device does look good, if it really combines amp-hour counting with a Smartgage voltage algorithm  then it would be almost perfect, I'm surprised its not more popular.

 

......................Dave

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6 minutes ago, Loddon said:

News to me about discharge and 80% how did you discover that?

 

Somewhere on this site, in the dim and distant past, Gibbo said it, or was quoted as saying it, or a link was posted to a quote from him.

 

There is no way I will be able to find it, but I recall his words being along the lines of:

 

"Why on earth would anyone need to know the SOC if they are discharging, but above 80%"

 

In reality, he is correct. My gripe is the fact that it is promoted as a petrol gauge type thing, but is unreliable at the most critical time.

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