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Author Topic: low output due to small batteries ?  (Read 2018 times)
donegal
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« Reply #30 on: October 09, 2017, 11:54:25 PM »

Jonesy,

Ac ripple in a DC battery, i had to google that one as i thought it might be navitrons version of stripy paint,  i check it out further.

The option of the 750w load is do-able as the 1500w immersion has two elements, so i can rewire it and remove the links. i would still need the chinese controller to make sure i have enough load, or the second tristar.  perhaps that my next job.
I'll have to have a think, theres a lot to digest.  Which is a good complaint as i had run out of ideas only a week ago.

Thanks
Tony

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donegal
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« Reply #31 on: October 10, 2017, 01:05:01 AM »

Biff,

Where to start, thanks for the photos, that's something i should have done earlier. Im sure your right about the PV being easier to troubleshoot,  i added the chinese controller in tonight just to give the AC loads a try.  There was something happening, but you really need daylight so you can see the trees etc and judge if its the windspeed that's changed.

I cant see there being any quick answers on this one, i will try the changes in the last post, but i am going to think over things for a day or two and re-read the thread back (until i get the thermal camera). If i cant find the problem, then i may need to determine what's working correctly (and write it down!), there are too many variables at the minute for me.  im sure plenty of you have said as much, in another way.

This is probably as good a post as any to say how amazed i am with all the comments, from everyone, its so rare to see everyone attacking the problem, rather than each other, its a very impressive forum, and really appreciated.

Thanks
Tony
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biff
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« Reply #32 on: October 10, 2017, 12:27:51 PM »

Thanks for the offer T,
                        It would not be convenient at the moment but maybe some other time in the future. Goodness knows i do need a visit from the thermal camera but not at the moment. I am reduced to sign language and writing notebook. Thanks again.
                                               Biff
On a night like tonight,
    A small ac load on the inverter side,  something like one of those (850watt?) Aldi drills with variable speed,turned down to 3 or so, Turn it up gently by degree  but be sure to shut it down gently, Study turbine carefully.  If you pull too much and small bank cannot cope, alarm will sound, the little China man will look glum and shut down the inverter but don,t worry, wait a moment, reduce demand ,switch off and then switch back on. Chinaman will then look happy once again and you are back in business,  Or maybe a small load of 150watts.  Grin  Keep an eye on the right side of the Chinese controller while using drill. Ease it down in speed before cutting power to the drill. Match Immersions as soon as you get a chance, with the small one cutting in first. Don,t push the drill to the max. You only need a few moments to see what is happening.
If you can find a way to measure the amps going to the immersions, you can let me know.
« Last Edit: October 10, 2017, 05:30:48 PM by biff » Logged

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jonesy
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« Reply #33 on: October 10, 2017, 09:12:02 PM »

Good point about the braking Biff. The battery voltage on a small bank will rise much quicker than a large one, so the system is probably applying  the brakes quicker.

The ripple is worth looking for as it's quick and easy. So not a sky hook, or stripy paint. Like I'd do that  Grin
 
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donegal
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« Reply #34 on: October 13, 2017, 05:03:12 PM »

Just to give you an update on this,  im still thinking over the options, but getting there !.

I spent a few hours on wednesday tweeking things, not really addressing the problem, but just trying to understand things better.

Things ive learnt :
- if you turn tristar dip 7 off in diversion mode it puts the full immersion load onto the battery.  I did this for a few seconds and the tristar registered a diversion load of 27.9 amps. To me this shows that the immersion is circa 1500w, the wiring is ok and it is probable that the tristar is working OK.
-  a 450w 48v dc load on the turbine stops the turbine dead and only lets it provide low power for a few seconds before it stops again, this was wired in instead of the chinese controllers dump load.
- An AC load on the invertor at the same time does increase the output of the turbine and gives longer 'run times' before it drops back to zero amps.
- When the chinese controller turns on the fans initially it puts a very small load on the turbine via the dump loads  (say 3v), but this is enough to control the turbine and reduce output in all but a constant wind.
- the 3 phase ac is approx 40.5 volts across any two cables of the three, which appears good.
- A continuity test gives the same rapid beeping across any of two of the 3 phase ac cables.
- the voltage drop from the rectifier to the tristar is in the region of 0.2-0.5 volts,  i need to check the accuracy of my meter and the tristar display to confirm this.


Things i need to check :
- Does an AC load on the invertor give an overall better output than the tristar was obtaining, im not sure, possibly,
- Does the above 450w immersion work better when connected directly to the batteries rather than the controller, ill use a manual switch for now, possible a relay later at a lower voltage than the tristar. ill also switch it in when the turbines running.
- Does the chinese controller electronically brake the turbine, almost definitely, there is also a manual brake switch .  im hoping the thermal camera might show whats happening when you flick the brake switch and i can then see if similar is happening at 10 amps.  i realise that's not very technical for any electricians reading this,  but it keeps my hands and bits of metal away from live components.
- check the other immersions i have to confirm the wattage , wiring etc.... using dip switch 7.
- a whole list of items listed in the thread
- if im brave (or foolish enough) i might put the whole 27.9 amps (dip 7) load on the turbine in a good wind, its the shutting down of the tristar to change settings thats the problem. or possibly remove the link in the immersion to give a 750w load and use dip switch 7.

Im starting with the simple items, but if i discount the immersion, cabling to immersion and tristar as being ok,  then that just leaves the turbine, batteries and controller / rectifier as the problem.

As the chinese controller and rectifier both gave similar results, its looking to me like a turbine or battery problem ?. im still convinced its the battery, we need an emoji of a "dog with a bone". As with all things turbine related, i reserve the option of totally changing my mind, as first impressions are seldom right.

Im working on the principal that the flow of amps is always determined by the load, and therefore im going to try to increase the load on the turbine, similar to Biffs AC load, but dc.  The AC load may have already gave me the answer, as i was  getting 3 amps to the ac load and  momentarily an 8 amp diversion,  but i need to repeat this and confirm that the battery voltage was stable.

A lot of the items above address the queries raised earlier in the tread, i still need to re-read the thread and add to the to do list, then work out the easiest sequence .  some need the Chinese controller in place, some would be better with a simple rectifier.

Regards
Tont


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biff
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« Reply #35 on: October 13, 2017, 06:51:35 PM »

Errrrr  (Clears throat)  ,
        Errrr,  Not a good idea alt all, at all, at allll T, Shocked, to draw off on the dc side, unless you know exactly what it takes to keep the Turbine braked, The wind energy that goes directly to your immersions does not behave like PV energy, It is delivered in clumps, lumps , Rushes and flushes. There is nothing steady or constant about it, unless you are in a force 8 and then it pulses more rapidly,according to the size of the AC load. The correct ac load on your Chinese inverter will allow your Turbine to get up into 5th gear and cruise gently past the dump load voltage and brake gently. You will have to stare hard at the blades to see the braking shuffle.
  You have quite a serious breeze down your way Shortly,. You need not wait until hours before it is due. Consult the Met-Eireann charts, the 5 day forecast and pick the time to lower your baby. Be careful.
                                                                               Biff
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donegal
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« Reply #36 on: October 13, 2017, 07:38:39 PM »

Thanks Biff, noted.

I was hoping that the 450w immersion on the battery, if switched on when the turbine was running at say 8 amps would take all that 8 amps  and
i was then  hoping to see the tristar start diverting if the voltage rose .  The plan was that the tristar would still be in the background to keep things under control with the 1500w immersion if/when the voltage rose. The aim was to get an output from the turbine that was clearly over 8 amps.

Does that change things or is it still a bad idea ?
I'll have another go with the AC load in the meantime, it does totally change the behaviour of the turbine,  i cant begin to think how you discovered that one or how long it took ?, i am seeing result, but not as impressive as yours.  maybe more patience is needed or maybe this 10amp limit on the chinese controller fans on etc....(in my case) is killing the momentum.  I'll keep going, but wont get much done this weekend.

I going to be very cautious and drop the turbine tomorrow afternoon.

I passed your way today, the turbine was going well !.

Tony
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donegal
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« Reply #37 on: October 13, 2017, 07:59:09 PM »

Good point about the braking Biff. The battery voltage on a small bank will rise much quicker than a large one, so the system is probably applying  the brakes quicker.

The ripple is worth looking for as it's quick and easy. So not a sky hook, or stripy paint. Like I'd do that  Grin
 


The voltage rises almost instantly, which could be good as a very high percentage of the power goes straight to dump, but may be bad when it comes to building momentum. i cant work that one out yet!.
regards the ripple test, can you just use a standard multimeter  ?

4  Battery impedance increases with age to the point it's too high for the battery to be usable, as it can't deliver current. It might affect ripple. Can you measure the AC ie ripple at the batteries when fully charged with a good AC DVM at little wind and max wind.

This interested me, would a test of the battery impedance be a good idea ?

Thanks
Tony

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donegal
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« Reply #38 on: October 13, 2017, 08:09:25 PM »

Morning Donegal,

I think the controller is the problem and not the batteries. Methinks what  you  need to do is set the diversion mode on the TriStar lower (say .5V) than the diversion on the controller. This will effectively stop the controller sucking power until the immersion turns off or fails. The controller will then start to work as the system voltage rises a little over the Tri Stars set points. I've done a couple of systems like this and it works fine. Of course the other thing you could do is bin the Tri Star and just get an immersion element the same size as the one in the controller and take the one out of it  Grin Or bin the controller and fit two Tri Stars with the same .5V set point difference and have an air element on the second one.

Good luck, Paul

Paul, 

I will use the custom setting on the tristar to test 3 different voltages, say float at 52, bulk at 54 and 'equalise' at 56.4, just as a temporary test
to see if anything changes.  i dont think i tried this with the simple rectifier.
Its always in the back of my mind that you've had success with similar systems, can you recall if there were any notable differences compared to my schematic.
And thanks for the schematics, i missed responding to that post, i was too busy trying to post my schematic.
Two tristars were always the intention, ill see how things develop.
Regards
Tony
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jonesy
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« Reply #39 on: October 15, 2017, 02:15:07 PM »

regards the ripple test, can you just use a standard multimeter  ?
Yes. A DVM  anyway. They are all pretty good now.

This interested me, would a test of the battery impedance be a good idea ?
It depends how you measure it, as there are both ac and/or dc tests. And how would you deal with a good/bad result? I'd leave it on the back burner for now. You've shown the battery can deliver a good current into the diversion by flipping DIP switch 7, if only for a few seconds.

Does your chinese controller fit the entire range, or do they provide a range of them?  There's not a menu setting dependent on the model you own?

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donegal
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« Reply #40 on: October 31, 2017, 12:10:42 AM »

Just an update,

Between storms, ex hurricanes, calm spells and work, i haven't really moved on since the last post.   The only thing i did find was that after 3 days of calm weather the batteries were sitting at 47 volts !.  One was at 9.7v and the other 3 were approx 12v.  So im waiting for a replacement battery before i go any further, its in the post. I presume the weak battery was dragging the other 3 down in voltage.
The wind picked up within 2 hours and they got a decent charge on Saturday, after a calm day there now back down at 51v.
I dont know whether the weak battery will have any bearing on the turbine output ?, but it obviously needs replacing. hopefully they'll get a charge tomorrow morning, if not i'll disconnect them and charge them individually.

I did have the thermal camera for a few days, but didn't find anything amiss,  two of the batteries did show a few degrees warmer at the base, i must have a look on the laptop and see if one of them was the 'dud' battery. The turbine doesn't appear to heat up at all in moderate winds, which is good.

As before, this could take some time, but i'm learning all the time.

Regards
Tony
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donegal
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« Reply #41 on: October 31, 2017, 12:25:27 AM »



Does your chinese controller fit the entire range, or do they provide a range of them?  There's not a menu setting dependent on the model you own?


[/quote]

Jonesy,  The controller has no settings, just a display for the battery voltage and charging current, i maybe wrong, but i dont think its the problem as the rectifier gave the similar results.  Both appear to brake (or restrict) the rpm similarly, just the chinese controller is more aggressive or obvious due to the slight groaning noise from the turbine when 'braking'. i cant really say that one setup performed better than the other.

The reason i mentioned the battery test is that i wanted to add some more items to the list that of things that appear to be working OK, but as you'll see in the post above one of the batteries gives a low voltage reading, so i'll see what happens when i swap that one out.

Thanks
Tony
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eabadger
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« Reply #42 on: October 31, 2017, 11:34:12 AM »

sound to me like your "lost" power was trying to charge batteries?
if you dont need the batteries, why not just have one?

steve
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1kw wind turbine.
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donegal
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« Reply #43 on: November 02, 2017, 06:46:07 PM »

sound to me like your "lost" power was trying to charge batteries?
if you dont need the batteries, why not just have one?

steve

The new battery is fitted, so just waiting for some wind to see if there's any change.  I'm not sure what you mean by the last line ?

Tony
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