Energy production logistics

[Ex- Member]

Now 4 months on the water and a month or so into winter we’re finding that generation of energy hasn’t been anywhere near as tricky as we thought it might be, although there's a fair way to go before we can rely totally on our 740W of solar panels again.

We were almost totally self sufficient with solar up until the end of October. Since then we,ve had to run the engine for 33 hours to compensate for required energy. TBH though I’m pretty sure we could have avoided a lot of that engine running time and saved a fair few quid in fuel costs.

We also have a 2.6 Kipor generator, it was stored in the back of the engine room, and to be honest I was just too lazy to get it out and up and running so just used the main boat engine for battery charging. However as boat engine usage began to rise I made the effort.

Had a few niggles with the genny as it hadn’t been used for around 6 years, but got it running properly by the end of the day. Now! I have had planned a small Kubota diesel engine strapped to 2 x 90 amp alternators, which will be built in the engine room fuel fed from the main tank and exhausted through the hull, and used for bulk charging. But since using the petrol generator I’m wondering weather it’s actually worth it.

When we first started running the petrol generator, we would run the boat engine for an hour sometimes 2 first. This would put in around 75amps reducing to about 50 amps within an hour if the batteries were low. I bought a clamp amp meter which is surprisingly accurate to monitor inputs.

After running the boat engine we would then run the Kipor, the great thing about this is it will charge the BB via a 20 amp mains sterling charger plus there’s a direct 12v 8 amp charging output as well, and whilst charging the BB it also supplies what ever 240v appliances we have running on the boat at the time, so in effect giving the batteries a bit of a rest whilst being charged.

Now when we first started this regime the batteries were very low, we ran the kipor for over 4 hours one evening in an attempt to reach a full SOC which we did not achieve in that time but it was late evening by now. I was also amazed the Kipor had not run out of fuel, so planned to top it up in the morning.

Next morning I decided to dip the tank just to see what was left and extremely surprised to see a good half tank of fuel remaining, and the tank wasn’t completely full to begin with. Anyway It was another overcast day just a couple of amps from solar, so I ran the generator again, amazingly 5 hours later it was still running and the batteries must have been near full as only a couple of amps were going in from the sterling 20 amp charger. I dipped the fuel tank and this time it was almost empty. But 9.5 hours from a not full tank of fuel was pretty good I thought.

We started using the Kipor 3 weeks ago and have now settled to a good steady charging regime that seems to be working really well for us considering we run a 240v fridge 2 laptops one 17” and a 30” tv plus 240v CH pump and all the many other 12v incidentals. So now if it’s a sunny day we don’t usually need to run the boat engine at all but run the Kipor for 2 to 3 hours in the evening depending on how much PC gaming I’m doing.

But even on an overcast day where we sometimes need to run the boat engine for an hour + and then the Kipor for 2 to 3 hours in the evening it’s really not costing that much. I’m currently doing a fuel consumption test on the Kipor and have filled it with exactly 5 litres from empty, I reckon it will run about 9 hours + on smart throttle possibly more. 5 litres of petrol costs £6.50 at £1.30ppl so running cost is about 72p per hour.

I would probably be wiser getting a 40 or even 50 amp mains sterling/victron battery charger if sticking with this regime, as this would further reduce boat engine running time, as I check the charging amps every 30 minutes and as soon as the charging amps go below 40amps I then switch to the Kipor. With a hire amperage mains charger the boat engine could be switched off earlier.

Using this regime we have also been able to regularly reach a full SOC twice a week which is generally good for the batteries, the outback has also performed a couple of equalization's in the past month as well.

We also have a small Honda 20 amp dedicated 12 petrol generator, I'm collecting it from our depot this week, i reckon it will be good for trickle charging to full SOC as you can reduce the amps output which slows the engine revs giving superb fuel economy. So I could turn the Kipor off when batteries are receiving under 10 amps then switch to the Honda.

A bit of a long winded post i know, but there’s so many different ways of charging, working out the most efficient is quite some process. And for us we only need to worry about engine & generator battery charging for about 3 to 4 months of the year, so I’m wondering weather fitting our home made 12v diesel generator is worth it.

Of course sods law it’s almost finished but could be sold on. I will also add the main reason for the diesel 12v generator idea was a reluctance to have to use and store petrol on the boat. I’m no H&S nut, but petrol can be a volatile fuel, so this is also a factor.

[Dave Payne]

Intersting post, cheers.

 

Can i ask what sort of cost your panels were?

[Phil Ambrose]

Julynian, great post, nice to see you appear to have cracked the power problem for your case. Please keep us updated

Phil

[Ex- Member]

Intersting post, cheers.

 

Can i ask what sort of cost your panels were?

Hi Dave

 

The panels were all well under £1.00 per watt, I can't remember exactly but within5% of £600 We also fitted a top of the range MPPT controller which was a bit expensive but you could easily buy the required MPPTcontroller and cabling for under £400.

 

If you budgeted a grand and fitted yourself, you should have enough change for several beers and throw a small party to celebrate a fare whack of free energy for the next decade or so

[leeco]

I hope to have my power like this soon.

 

great thread.

[Ex- Member]

Julynian, great post, nice to see you appear to have cracked the power problem for your case. Please keep us updated

Phil

 

Cheers Phill, the experimenting is great and a good learning curve too. It's like your battery bank becomes a living entity and if you feed it well it will reward you

 

Or am i becoming energy OCD

 

I'll certainly post about this little Honda 12v charger, I think it will work well for trickle charging to full SOC, Well see!

[nb Innisfree]

In the good old days before we became landbound we would do a bulk charge with the main engine for a couple of hours each day and approx once a week finish off with an eight hour absorption charge using our Kipor 2kva inverter genny and Victron Multiplus, I would half fill it with petrol and it would run on tickover for 8hrs, tank holds 3.7 litres.

[Ex- Member]

In the good old days before we became landbound we would do a bulk charge with the main engine for a couple of hours each day and approx once a week finish off with an eight hour absorption charge using our Kipor 2kva inverter genny and Victron Multiplus, I would half fill it with petrol and it would run on tickover for 8hrs, tank holds 3.7 litres.

 

That's interesting, I reckon the 5litres in this 2.6 kipor will go over 10 hours now. We ran it today and yesterday totaling 4.5 hours,and there's still well over half a tank left. Should know the exact usage figure by Friday.

 

How many amps did your Victron Multiplus charge at BTW We just have a 20 amp sterling at the moment, it served us well on dry land with mains connected, but would probably pay to upgrade a bit if powering by generator.

[Dave Payne]

Hi Dave

 

The panels were all well under £1.00 per watt, I can't remember exactly but within5% of £600 We also fitted a top of the range MPPT controller which was a bit expensive but you could easily buy the required MPPTcontroller and cabling for under £400.

 

If you budgeted a grand and fitted yourself, you should have enough change for several beers and throw a small party to celebrate a fare whack of free energy for the next decade or so

 

 

Doing some very simple maths, the system should come into fruit after 12 months, meaning £1000 would be about what it would cost you to charge your batteries from your engine every day?

[nb Innisfree]

 

That's interesting, I reckon the 5litres in this 2.6 kipor will go over 10 hours now. We ran it today and yesterday totaling 4.5 hours,and there's still well over half a tank left. Should know the exact usage figure by Friday.

 

How many amps did your Victron Multiplus charge at BTW We just have a 20 amp sterling at the moment, it served us well on dry land with mains connected, but would probably pay to upgrade a bit if powering by generator.

Capable of 70amps @24v, needs 2.5 kw input for that, could just manage approx 44amps at Kipor rated output of 1600 watts

[ackdaw]

good post interesting stuff

[dmr]

Very interesting stuff (for me anyway), Thanks Julynian, and please share your updated petrol consumption figure when you get it. 72p/hour does sound possibly a little too high.

We do everything off the main engine and have only a tiny bit of solar. I do sometimes worry about running the main engine for hours when we do the equalisation charge.

So lets look at our costs.....

We can do the absorption charge on tickover where we use about 0.9 litre/hour so if I can get diesel at 80p this is also 72p an hour !!!!!!!

We don't have the agro and risk of keeping petrol on the boat, getting the genny nicked, upsetting the neighbours, etc and the engine makes hot water and puts a lot of useful heat into the back cabin.

 

Running at tickover is not nice for the engine so if we put some revs on we do about 0.95litre/hour. However we now have good 240volts off the travelpower so can run the washing machine. 95p/litre is probably a more realistic diesel price on the K&A, though Spencers diesel boat sounds very interesting.

95p at 0.95l/hour gives 90p/hour

90p at 0.95l/hour gives 86p/hour

Still not too bad and all that free heat in the boat.

 

What's probably more interesting is to take an accountants view and estimate the true cost of engine running. We need to include service costs and take a guess at engine life expectancy and the cost of replacing it when its worn out. I make it £2.06 per hour.

 

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

[Ex- Member]

Very interesting stuff (for me anyway), Thanks Julynian, and please share your updated petrol consumption figure when you get it. 72p/hour does sound possibly a little too high.

We do everything off the main engine and have only a tiny bit of solar. I do sometimes worry about running the main engine for hours when we do the equalisation charge.

So lets look at our costs.....

We can do the absorption charge on tickover where we use about 0.9 litre/hour so if I can get diesel at 80p this is also 72p an hour !!!!!!!

We don't have the agro and risk of keeping petrol on the boat, getting the genny nicked, upsetting the neighbours, etc and the engine makes hot water and puts a lot of useful heat into the back cabin.

 

Running at tickover is not nice for the engine so if we put some revs on we do about 0.95litre/hour. However we now have good 240volts off the travelpower so can run the washing machine. 95p/litre is probably a more realistic diesel price on the K&A, though Spencers diesel boat sounds very interesting.

95p at 0.95l/hour gives 90p/hour

90p at 0.95l/hour gives 86p/hour

Still not too bad and all that free heat in the boat.

 

What's probably more interesting is to take an accountants view and estimate the true cost of engine running. We need to include service costs and take a guess at engine life expectancy and the cost of replacing it when its worn out. I make it £2.06 per hour.

 

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

 

Hi Dave

 

It's boat engine time I'm most interested in elimination for the most part. you make a good point though about it heating water also, that's why we always run for an hour at 900 rpm, it gives us enough hot water for general use, the stove also heats the water too, so engine running for hot water isn't a priority but does get it up to temp and the boat stove can maintain it.

 

The clamp meter I bought is a brilliant too, after an hours engine running I'll take a reading, if over 40 amps are still being absorbed I continue running until around 35 to 40 amps. The main engine running time will depend on the weather, on bright days we can even not bother running the main engine and just the Kipor for an hour to even 2 hours, but we also switch off inverter and run all other boat 240v appliances as well.

 

Im just picking up this wee Honda 12v petrol generator I got several years ago. I think this will be ideal for the final trickle charging. I've just had it running and I can drop the engine speed to a very low idle almost to staling point, so I reckon it will be a very efficient way of putting in low amps at very little cost, as this wee init can run for 6 hours on 0.25l at half power of petrol which I will also double check the consumption of. but if correct that's just 27p per hour.

 

I would like to ask any of the boffins just how long it takes to bring a 700 amphour battery bank to a full SOC from the point the batteries will only accept a maximum 10 charging amps. I don't know if there's a calculation specifically for this, but it would give a good idea of charging time.

 

So basically is there some ratio when BB absorption reaches 10 amps, it would take then need a 2 hour charge at 5 amps to attain a full SOC "for example"

 

Or is there a rule of thumb that says when the BB only accepts 10 amps it's at a xx% SOC scaling down to 1 amp or 0 amps

 

~Edited to change to 0.25l

Edited December 11, 2013 by Julynian

[nb Innisfree]

I would like to ask any of the boffins just how long it takes to bring a 700 amphour battery bank to a full SOC from the point the batteries will only accept a maximum 10 charging amps. I don't know if there's a calculation specifically for this, but it would give a good idea of charging time.

 

So basically is there some ratio when BB absorption reaches 10 amps, it would take then need a 2 hour charge at 5 amps to attain a full SOC "for example"

 

Or is there a rule of thumb that says when the BB only accepts 10 amps it's at a xx% SOC scaling down to 1 amp or 0 amps

 

~Edited to change to 0.25l

Bit unsure of 'boffin' but it takes at least 24hrs to fully charge a battery irrespective of its size, how much of this is taken up with bulk charging depends on amount of amps going in.

 

2% of batt capacity is considered to indicate 100% SoC but a truer figure would be 0.5%, in any case it's impossible to achieve a true 100% SoC.

 

Batteries are doomed.

[dmr]

Bit unsure of 'boffin' but it takes at least 24hrs to fully charge a battery irrespective of its size, how much of this is taken up with bulk charging depends on amount of amps going in.

 

2% of batt capacity is considered to indicate 100% SoC but a truer figure would be 0.5%, in any case it's impossible to achieve a true 100% SoC.

 

Batteries are doomed.

 

We are all doomed! but the concept of living on a boat is to enjoy life whilst we can.

 

There is not a simple answer to how long it takes to get to 100%. I suspect it might be that you never can.. hence the battery is indeed doomed, but you can get very close. I reckon the problem is that the time to 100% will depend on what you did yesterday, and what you did the day before.

If you got to 100% yesterday then maybe 8 hours will get you very close today, but if you only did a 80% charge yesterday and the day before then its going to take longer as there is already a bit of sulphation starting. Upping the voltage just a little might also shorten the time quite a bit. Maybe a little mini equalisation (an hour at 15 or 16 volts or so) at the end of every charge would help (have a look at the Trojan data sheets).

Maybe nobody really knows. Maybe Gibbo knows but he won't talk to us anymore.

I think ultimately we need to decide how long the batteries will last then do sufficient charging such that they only get a bit of sulphation by the end of their life, charging beyond that is just a waste of money.

 

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

[nb Innisfree]

 

 

I think ultimately we need to decide how long the batteries will last then do sufficient charging such that they only get a bit of sulphation by the end of their life, charging beyond that is just a waste of money.

 

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

Hence the 50% 'rule'

[Ex- Member]

Full SOC not so much a problem in the summer though, when we had just 500 watts of solar we were on many days through the summer in float mode with excess energy, so now with 740 amps we'll be able to regularly reach a full SOC from March to October.

 

We spent the whole day away today, we think it was pretty sunny here. For an experiment we switched all power off both 12 and 240v We ran the Kipor last night for 2 hours from 5 til 7pm we had lap tops fridge etc etc on, and then stupidly I watched TV til 230am, not a habit honest LOL

 

Anyway when we got up 7am the batteries were reading EMPTY on the guage, although everything was running fine. I was quite shocked! so we ran the engine for a quick 30 minutes as we had to be off by 8am So we also decided to switch everything off' for the experiment.

 

Got back this evening 5.30 and the batteries were reading 12.5v and between 3/4 and full. Now if the batteries were really near empty, there's no way the 30 minute engine running in the morning and solar, would put in enough energy to recover that much. The gauge often reads low and the volt meter been as low as 12v, but every time we switch all off which we sometimes do if we go out all day, we get this seemingly amazing recovery. I will look up the Outback log tomorrow to confirm the actual amps it did glean yesterday, I wouldn't think more than a hundred though.

 

We ran the Kipor again tonight for 45 minutes, took another amps reading and the BB was only taking 3 amps from the Sterling 20 amp charger and 2 amps from Kipor12v 8 amp direct. That surprised me too.

 

Kipor is now been run for 4 & 3/4 hours, still over half a 5L tank left I reckon.

 

I used to be a bit paranoid when the needle hit half on the analogue or the volt meter hit 12.2v but now I'm generally ignore it as if an hours boat engine running time and 2 to 3 hours generator running producing 28 amps result in the batteries only accepting 5 amps of that possibly 28 after just that time, then the batteries are in reality not very often anywhere near 50% SOC but for some inexplicable reason can register reading near empty. it's wizardry surely LOL

 

Engine amps max 80amps for 1 hour and Kipor max amps 28 fo 2 hours

 

Anyone know why this is

Edited December 11, 2013 by Julynian

[smileypete]

If you want to add some charging capacity alongside the sterling, one of these current limiting supplies might do alright:

 

http://www.ebay.co.uk/itm/400W-15V-26A-Switching-Power-Supply-Current-Control-Charger-LED-CCTV-UKX-/380779134900

 

Though it needs a professional install with properly crimped ring terminals, well secured cables, properly enclosed connections and so on.

 

Pretty well all the info you could ever need or want about batts is on the US Battery and Battery FAQ websites, the Trojan site too though IIRC you have the US Batts. I'd just do partial charges in the week to say 80-95% following the US Battery instructions as closely as poss then give a good long 100% charge to their instructions at the weekend.

 

I wouldn't worry to much about taking them down to 20% SOC, though of course they'll take longer to recharge from that level. OTOH if there's an opportunity to do some bulk charging say in AM as well as PM then why not.

 

First thing in the morning is a good time to check the resting voltage and gauge the approx state of charge, sounds like the batt gauge you have shouldn't be relied upon.

 

I reckon a novel way to EQ batts in winter without the long genny run would be isolate part of the bank then fully charge and EQ from the rest of it though a DC converter, though a normal batt bank setups doesn't allow this. This is the sort of converter I had in mind :

 

http://www.ebay.co.uk/itm/1pcs-Boost-DC-DC-Converter-Power-Supply-Step-up-Module-10-60V-to-12-80V-600W-mah-/251286948321

 

cheers, Pete.

~smpt~

Edited December 11, 2013 by smileypete

[nb Innisfree]

I reckon a novel way to EQ batts in winter without the long genny run would be isolate part of the bank then fully charge and EQ from the rest of it though a DC converter, though a normal batt bank setups doesn't allow this. This is the sort of converter I had in mind :

 

http://www.ebay.co.uk/itm/1pcs-Boost-DC-DC-Converter-Power-Supply-Step-up-Module-10-60V-to-12-80V-600W-mah-/251286948321

 

cheers, Pete.

~smpt~

It's the old split battery bank scenario again, why equalise one part of a bank when to do so will be to the detriment of the other part. What you gain on the one hand you lose on the other.

[Biggles]

I have been very interested in power generation. I have 500w of solar which is pretty good in the summer.

 

Here's the strange thing I think If I lived on the boat full time and cruised a couple of hours a day we would be fine for power.

 

My mooring is off grid. I started off with a 240v genny, but this was crap, so this is what I did.

 

http://dcgenset.blogspot.co.uk/

 

Linky

 

This morning my battery bank 1180a/h was at 90%. After an hour and a half of the 12v genset running the batteries were at 100% Charge rate at the begining was 184amps. Once 100% was reached the charge was 36amps.

 

12v Diesel powered battery charger is the way to go. IMO.

[nb Innisfree]

I have been very interested in power generation. I have 500w of solar which is pretty good in the summer.

 

Here's the strange thing I think If I lived on the boat full time and cruised a couple of hours a day we would be fine for power.

 

My mooring is off grid. I started off with a 240v genny, but this was crap, so this is what I did.

 

http://dcgenset.blogspot.co.uk/

 

Linky

 

This morning my battery bank 1180a/h was at 90%. After an hour and a half of the 12v genset running the batteries were at 100% Charge rate at the begining was 184amps. Once 100% was reached the charge was 36amps.

 

12v Diesel powered battery charger is the way to go. IMO.

How did you measure the SoC? If you did achieve 100% SoC in 90 mins from 90% SoC, which I doubt as your terminal charge rate was still at 3% of your assumed batt capacity, then you have somehow overcome the inherent prob with batts in that they take several hrs to reach 100% SoC. Edited December 11, 2013 by nb Innisfree

[smileypete]

It's the old split battery bank scenario again, why equalise one part of a bank when to do so will be to the detriment of the other part. What you gain on the one hand you lose on the other.

 

How will it be to the detriment of the other part of the bank?

 

For the rest of the bank its just normal discharge. US2200s EQ at up to 15.5V at up to 7A (C/30), so that's just over 3.5A off each other pair of batts, not too bad.

 

What'll be interesting is connecting the fully charged batt pair at 100% back to the other 2 pairs at say 90% but I expect they'll even out quite well. Wait a few days then rinse and repeat with the next 1/3rd of the bank.

 

Anyway a long genny run at the weekends isn't so bad if you can use the genny for other things at the same time, otherwise what, a fiver of fuel to dribble in a few amps of EQ current? Adds up a bit over the winter months.

 

How did you revive your knackered AGMs BTW?

 

cheers, Pete.

~smpt~

[nb Innisfree]

 

How will it be to the detriment of the other part of the bank?

 

For the rest of the bank its just normal discharge. US2200s EQ at up to 15.5V at up to 7A (C/30), so that's just over 3.5A off each other pair of batts, not too bad.

 

What'll be interesting is connecting the fully charged batt pair at 100% back to the other 2 pairs at say 90% but I expect they'll even out quite well. Wait a few days then rinse and repeat with the next 1/3rd of the bank.

 

Anyway a long genny run at the weekends isn't so bad if you can use the genny for other things at the same time, otherwise what, a fiver of fuel to dribble in a few amps of EQ current? Adds up a bit over the winter months.

 

How did you revive your knackered AGMs BTW?

 

cheers, Pete.

~smpt~

It will be to the detriment because the part of the bank used for equalising the other part will drop to a lower SoC than it would have if it wasn't used to equalise. It's like lifting yourself up in a bucket!

 

I revived them with long raised absorptions charges (28.8 -29.6v) via our Victron, mostly with Kipor genny but longer ones from various shorelines. They seem to be more or less fully recovered, never expected that, thought they were buggered.

 

ETA: You've got a good memory, it was a few years since they were nearly knackered!

Edited December 11, 2013 by nb Innisfree

[Biggles]

How did you measure the SoC? If you did achieve 100% SoC in 90 mins from 90% SoC, which I doubt as your terminal charge rate was still at 3% of your assumed batt capacity, then you have somehow overcome the inherent prob with batts in that they take several hrs to reach 100% SoC.

 

Love it or hate it I am using the information provided by my Victron BMV600.

 

This alternator really stuffs it to the batteries. This afternoon I was showing it to a friend and the charge rate was about 97%. I put the 2kw toaster on and was still charging the batteries 110amps.

 

I don't profess to understand the theory of battery charging, I assume when I buy a battery monitor form a company as renowned as Victron they have done the sums and produced a product as reliable as possible.

 

All I know is the genset I have built works. (according to my monitor) and my real life observations.

[nb Innisfree]

 

Love it or hate it I am using the information provided by my Victron BMV600.

 

This alternator really stuffs it to the batteries. This afternoon I was showing it to a friend and the charge rate was about 97%. I put the 2kw toaster on and was still charging the batteries 110amps.

 

I don't profess to understand the theory of battery charging, I assume when I buy a battery monitor form a company as renowned as Victron they have done the sums and produced a product as reliable as possible.

 

All I know is the genset I have built works. (according to my monitor) and my real life observations.

We have a BMV501, great bit of kit but the SoC % readout just can't be trusted, mainly because it needs the real capacity of the batts to be entered but that is virtually impossible to achieve on a practical basis, only Gibbo seems to have cracked the problem of reliable SoC estimation with his Smartgauge.

 

It's very difficult to achieve a reliable reference to get an accurate idea of performance, only really practical way is to see if battery voltage holds up over a period of time.

 

Your genny sounds great

Edited December 12, 2013 by nb Innisfree