When choosing a dump load for your charge controller, you need to find heater or heaters that will:
- Be able to dump the maximum current your combined wind and solar systems will throw at it at once.
- Not draw more current than the charge controller is able to handle. (Which is the number in the name of the controller – e.g. C40 can handle 40 amps maximum.)
A neat solution to finding a dump load for a charge controller is to use a big wire wound resistor that you can buy from an electronic component supplier. Look for ones with low resistance and high power rating. There are not very many to choose from, and their stock is always changing.
The resistor has two important numbers associated with it: resistance and power rating. Resistance determines how much current it will dump in your system and the power rating is a guide to the maximum safe wattage it can burn off without over-heating.
When choosing a resistor/heater for a charge controller we need to start by considering the system voltage. Say it’s a 12 volt system then the heater needs to be safe up to 15 volts. (Whereas 24 and 48 volt systems can go up to 30 and 60 volts.)
Use Ohm’s Law to find the current the heater will draw at this voltage (if the controller turns it on fully). For example if the resistance is 1 ohm (written 1R or 1Ω) then Ohm’s Law says:
Current = voltage/resistance = 15/1 = 15 amps.
Next find the power it will have to dissipate (as heat).
Power = voltage x current = 15 x 15 = 225 Watts.
In reality these resistors can take some overload (and the controller is unlikely to need to operate them continuously) so you can get away with a well ventilated 200 watt resistor, although my favourite is 300 watts. This makes a good building block for a dump load system. You can add more in parallel to dump more current (up to 3 in parallel for a Tristar 45-amp controller) and you can add more in series to go to higher system voltages.
Above is how they work in parallel and below they are in series. Each parallel circuit adds to the current that the heaters can draw. Whereas putting more in series adds to the voltage they can cope with.
All this is talking about a 1 ohm resistor. Like this one.
If you are working at higher voltages than 12, it can be more sensible to use larger resistors for simpler and more cost-effective solution. For example how about 1 ohm/1 kW resistors like this one? Or here it is at Farnell. Connect it to a ’24-volt’ battery that is being charged at 30 volts (equalising or in low temperatures maybe) and it will draw 30 amps. Power is 30 x 30 = 900 watts and so this heater is suitable for the job. It can dump 28 amps at 28 volts or 26 amps at 26 volts. (The amount of current it actually dumps depends on how much the controller has to throw its way.) Don’t use more than one on a Tristar 45 in a 24 volt system or you will overload it. (You can use two in series on a 48 volt system, and you can use two in parallel on a Tristar 60 safely.)
2.2 ohms 2kW resistors like this make a good load for a ’48-volt’ system where you need to dump 25 amps. At a nice battery voltage around 56 volts it will do that happily, and it will not reach its maximum power rating until 66 volts (which is probably more action than your battery is likely to want.)
I have often found 3.1 ohm resistors with a 300 watt rating that are good for ’24-volt’ systems, running at roughly 10 amps. You can use up to 4 of these in parallel (up to 40 amps at 31 volts) on a Tristar 45, and 6 of them in parallel on a Tristar 60. For a 48 volt system you have to connect them in series pairs, rather like the second diagram above.
Take care when mounting these resistors that they have plenty of room so that air can circulate and cool them. They do not get red hot but it’s wise to keep them far enough away from flammable surfaces like wood. You can put them inside a steel enclosure and make them look pretty slick but make sure they are not likely to be overloaded in there.
I like to solder the connections but sometimes it’s simpler to bolt them. Either way you will need to use high temperature, flexible wires to make these connections. Equipment wire or ‘tri-rated flex’ is good.
These heaters will make a gentle buzzing noise when the controller is working. It’s not a loud noise, but it’s definitely there, so if anybody in the building is uncomfortable about buzzing noises then you may have a problem. Often they end up being mounted in the battery shed. This won’t protect your batteries from frost (which mostly occurs on calm nights when even the hydro is drying up) but it will safely dump the power that would otherwise potentially damage your battery.
The photo below shows a dump load resistor mounted on a piece of threaded bar (allthread) that is simply screwed into a hole in the woodwork.
There are other kinds of resistor, for example these aluminium housed ones that are not suitable on their own.
This type of resistor needs to be on a heatsink of some sort. I have clamped them to hot water tanks, and produced some useful hot water that way. But they do need to be fitted to a surface that will take the heat away. Without a heatsink their power rating is drastically reduced.
Relay Drivers for load management
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Thanks for the information. Very helpful to me. Question; I originally was going with a 24volt system and then switched back to 12v. I however, already ordered the 3.1r 300 watt resistors. I dont see any problems scaling these for use with the 12v system..
do you?
The problem with using 3.1 ohm resistors at 12V nominal is that the voltage for dumping is only 14 or 15 volts, so the current will only be 4-5 amps. The resistors will then be dumping about 60-70 watts. So it may not be enough to keep up with your wind turbine or solar charging. It’s safe to do but it doesn’t use the resistors to their full potential.
Power (volts x amps) varies with the square of the voltage: If you halve the voltage on a resistor you also halve the current (current = voltage/resistance) and so you only dump 1/4 of the power you would have done before.
Thanks for your response.. I came up with the same conclusion..
I’ll just order the correct ones 1r 225 watts or 1r 300 watts
Tim
Hi Hugh, The whole issue of dump loads has puzzled me for some time but I think I’m starting to get the picture of what’s going on from Hugh’s explanation above and reading the Tristar manual several times. It’s really great to have this opportunity to discuss the issues.
I made a 4 ft 24 volt turbine in the old style from 2005 plans. I made a three resistance choice dump load from 10 watt 100 ohm resistors purchased from Maplin for £18.50p. I used 40, of these resistors connected in parallel to give me 2.5 ohms, 3.3 ohms and 5 ohms with three toggle switches bringing in 40, 30 or 20 resistors. I didn’t know which was going to be the best value to choose and living 80 miles from the turbine site meant I’m not there when the wind is strong and the dump load gets used. I had the 2.5 ohms value selected for a long time thinking that 30 volts divided by 2.5 will mean the dump load wants 12 amps. I don’t think my turbine will ever kick out 12 amps and after reading 6.4.4 in the Tristar manual where it states that the load is not limited by the source, wind, hydro etc, and will draw its rated current from the battery I deduce that if my turbine is producing 3 amps then the other 9 amps will come out of the battery. I’ve since changed my dump load setting to the 5 ohms value. I suspect that the best ohm rating for the dump load would be so that just a fraction more current is needed than the turbine will produce at max output?
Thanks Hugh, I didnt know how the Tristar controlled the diversion current. My understanding has increased significantly thanks to this subject being discussed.
Tim Rowe
When selecting a dump load for the tristar controller, you will have a range to choose from. The maximum current (minimum resistance) heater that you can use is where you hit the maximum current rating of the Tristar. The minimum is determined by the wind or other charging sources combined. In other words makes sure it’s not so big that it will damage the controller, but makes sure it’s big enough.
Don’t worry about your 12 amp dump load draining the battery. Even if the wind turbine is only producing 2 amps and the battery is full, the Tristar will only divert those 2 amps into the heater, and not more. It does this by switching the heater on for only 1/6 of the time. If the battery starts to discharge (for whatever reason) then its voltage will fall and the controller will turn off.
I don’t understand why we should care about maximum diversion load if Tristar diverts excess current only? According to your explanation if the wind turbine is only producing 2 amps and the battery is full, the Tristar will only divert those 2 amps into the heater, and not more. So I can use any heater with any maximum power even if the current is greater that Tristar’s nominal current. It is only important to be sure that wind turbine will not generate more current which can damage the controller. Am I right? I have Futurenergy 1 kW, 24V wind generator, TS-60 and 2 kW dump load. Is it ok? Thank you.
Hi Bogdan,
I am glad you asked this question because a lot of people are confused by this. The manual for the product (which is a useful source of information) is quite clear on this. The peak load current (current the load will draw at maximum battery voltage) must not exceed the Tristar rating.
This is not simply a precaution in case your wind turbine produces more than is expected. You can still overload the Tristar even if you are only dumping 2 amps.
How can this be? Remember that the controller works by PWM. When it is on it is exposed to the full current that the load draws. Even if this is only for a short time, it can overload the controller. The average may be low but if the peak of the pulse exceeds the controller’s rating then you can overload it. It will then shut down and your battery will be overcharged.
Thank you so much for the professional answer. You have dispersed my doubts. I found your amazing blog by searching for the information about dump load selection. The information you have provided was understandable to me from the beginning but the supplier of my windmill tried to persuade me conversely. I am going to read all your articles because your site is very valuable mine of information. Thank you for your job.
I have a question about the wiring scheme of the Tristar. I have windgenerator on my yacht. It is possible to load with a voltage up to 20 V, max 50 Amp. In the wring scheme above these voltages will be directed to the batteries, so also to the ‘users’ most of which do not like a voltage above 15 V. In this scheme the Tristar is only used to divert load to avoid overcharging of the batteries. It is not regulating the Voltage. Correct ? So I would need two Tristars, one to regulate the voltage and one to divert load in case of overcharging. Is this correct thinking ?
Hi Kees, You need to understand the relation between the battery and the wind or solar charging sources. The wind turbine and the solar panel can easily produce 20 volts or more when disconnected, but when you connect them to the battery then the battery controls their voltage. The wind turbine cannot push the battery up to 20 volts. The battery wins that battle.
The battery voltage will rise as the turbine charges it (pushes current into it) but it will be close to its nominal level. The wind turbine will slow down and get loaded up so that the internal impedance eats the rest of the voltage you would otherwise see. There is no need to have a controller in series with the turbine or the solar PV provided you have enough dump loads to handle all of the current coming in from the wind and solar sources.
Never connect your user loads to the wind or solar sources without the battery. Then you can be sure the voltage will remain safe.
I hope this makes sense,
Hugh
thanks a lot, Hugh, for this information. I am a nerd on V and Amps. I was afraid to use this scheme, because last year the alternator of the engine in my boat got berserk and delivered 19.6 V to the battery bank, and several instruments were burnt beyond repair. Other equipment items were malfunctioning. The batteries were full at that time.
Do I understand it right that this would not have happened with a Tristar with a dump load ?
best regards, kees
Kees, Your battery must have suffered some bad damage before it got to 19.6 volts (or possibly just some bad connections) but in a well designed system that would not be a likely thing to happen.
So long as you have capacity to divert all of the incoming current to dumps then there is total control of the battery voltage. Battery voltage cannot rise without a net charging current.
With engine-driven or solar systems it often makes sense to control the current ‘at source’ but with wind and hydro turbines it’s usually best to divert current to a dump load.
Your average lead acid cell (when in good condition) produces 2.2V. The typical car battery has six cells, thus a fully charged battery is at 13.2V. Provided actual voltage is not an issue it is better to use a higher voltage as the current is lower in direct relation. Ideally, in a 220Vac world this would be 17 batteries. The typical car battery is 40 Amp/ hours giving a realistic 7kilowatts for each Amp/hour rating. Using such a high voltage has other benefits, for instance, the dump load unit could be a geyser. For a 115Vac mains system the sum batteries would be 9. The initial expense is ultimately worth the cost, the storage of power becomes a lot easier, waste, thus less. I hate waste! Water is an excellent means of storing power.
Hi Peter,
You are right that higher voltage systems are more efficient but the higher voltage Dc is a bit harder to switch. I recommend 48-volt systems and have installed some 110 and 120 VDC battery systems but it’s harder to find reliable electronic kit for the less common battery voltages.
I don’t recommend you rely on car batteries for energy storage unless you have no alternative. 40 Ah at 12V makes 480 watt hours of electrical energy which is half a kWh unit and the battery will soon be destroyed if you use all of that each time you discharge it. Water is indeed quite freely available but you need to pump an awful lot or heat a big tank to store much energy with that.
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Good day, I have a solar system which has a 48 volt system, the batteries are charged from a Microcare 40 Amp MPPT ccontroller, this works just fine. I have a 3 kw. bi directional inverter which supplies my 220 volts. I also have a Samil grid tied inverter, now I want to hook the grid tie inverter after the 3 kw inverter, on its output side to take pressure off the batteries. The batteries are charged by a separate array of panels from the Grid tied inverter. Now when I hook up the G.Tied inverter to the output of the inverter she works fine as long as I am drawing near to what the G.Tied inverter is putting out, if I draw less it feeds back via the bi directional inverter and charges the batteries and this is obviously not regulated and the voltage rises to 65 odd volts which is not good. Is there a simple way I can shunt to excess power when I am using less that the system produces? I need to get the voltage down to between 50 and 55 volts. I am using this as I need the bi-directional inverter to pexcite the grid tied inverter then they work together. Any advice would be appreciated.
Hi Willie, The Tristar with diversion load would be a perfect solution to this problem. It will regulate the battery voltage regardless of where the current is coming from even if it’s coming back off the inverter.
You can set the voltage close to the settings of the microcare unit and it may (at times) dump the current coming in from that but that won’t matter, so long as they can regulate the total incoming current between them at a suitable voltage. Even if they do not always agree precisely about the charging voltage they will act quite well as a “committee”.
Thanks for the above, I will look into it, I presume the terminals of the tristar are to be connecter to the battery terminls direct?
I have another one, if this is not the correct forum, please tell me. I have Samil Grid Tied Inverter as above in my earlier comment. When connected to the grid and running, my pre paid meter still deducts units even when I have no load at all, in other words all the power generated is going to the grid and I am having to pay for them to take it, not really on is it? When I have a load on near to the same value as it is generating it stops and of course wen I use more than the inverter produces it deducts, so the meter moves forward which ever way the power if flowing. Any comments from anyone please? Interesting stuff> Willie
Hi again, Yes you connect the Tristar to the battery (through a fuse or breaker). It does not care whether the current is from the wind, the sun or perpetual motion it simply makes sure that the voltage does not rise above the set point and it does this by drawing/diverting current from the battery to a dump load.
As for metering on the grid I don’t know a thing sorry.
Good day, “ADMIN”, my error, in hindsight was obvious, I used the amp/hour rating as a multiplier, However, your reply that finding reliable switching units is a good one. To Willie, above, let me say that I believe his problem is in phase correction. I have seen power stations with very large correction capacitors, in fact my father nearly died with one faulty cap, it recharged when the bleeder resistor was disconnected. I am moving to the Western Cape and will have tons of wind and sun, I still prefer the higher voltage and will happily install nine giant batteries, so a 115V system. Yankee(or Confederate) equipment and 10 kilowatt transformers are not so difficult to find, I can parallel a few transformers so as to up the voltage to 220 if I must. (I don’t mean adding the outputs of the transformers) I will be installing an assisted solar geyser so the dump will be simple, just a voltage sensor to a solenoid. The heating element does not really care whether it receives AC or DC. Does the Tristar cater for the higher voltage or must I wind a few transformers?
hi Peter,
My name is Hugh, it’s just that I am the administrator of this site. Maybe I need to create a new identity in the system that signs my actual name!
I am sure you will have a lot of fun with the high voltage system but it’s a step further in ‘doing it all’ than most people want to go. The Tristar controllers that are the discussed on this page are designed for battery voltages 12, 24 and 48 volts. You will more likely devise your own charge control system based on your own voltage and your own ideas, but if you wanted to use Tristars to control a higher voltage battery then you would need to connect them to parts of the battery rather than to the whole.
For example if you have 9 batteries then you could use 2 tristars configured for 48V (each on a 4 battery string) and one configured for 12 volts for the remaining battery. This would be clumsy, but it would do a slightly better job of caring for the individual batteries than the single dump load that operates on a cue from the total battery voltage. (You could also configure the Tristars to work with 36V batteries, and then use 3 of them, on 3 batteries each, but you’d need to connect a computer to the Tristars to program them for this.)
Hugh, I understand your reply. It possibly also explains why high wattage UPS’s are so expensive. The standard ones, come to think of it, use 3 or 4 twelve volt batteries. However, your point about the forum is taken. In that spirit then, because Willie’s point about power meters not reversing is understandable if the phase correction is not done. If he is out of phase then his side is effectively a load on the mains supply. I can think of only one SIMPLE way to change that and that is via a 1 to 1 transformer. It could also be possible for Willie to change the two wires around , that is, his neutral might be the mains live and the opposite for his live. A simple explanation would be it’s like connecting two batteries reverse polarity. I shall continue my own research but economics could force my return to the 48v system. If life was simple, ect.
Hi Hugh,
Thanks for the info, really helpful. You are a legend…
Best wishes,
Pete
Hugh,
You are a legend. I am about to install a 48v hydro turbine. It’ll be paired to a 2kw PV system, run by an Outback Flexpower “panel.” I am now contemplating what kind of dumpload system to use. I’ve gotten the Tristar 45 as a dedicated controller, and I’m thinking about using wirewound resistors as you discuss in your article.
Here’s more discussion about the project from the Ariz Wind & Sun site (see link below). I’d value your comments (here, or there).
Cheers,
SP
http://www.wind-sun.com/ForumVB/showthread.php?15586-Controller-choice-amp-dump-resistance
Hi SP
thanks for the link. Interesting discussion.
I stand by using one controller for both hydro and solar PV in diversion. The pv controller if there is one can be simply for MPPT. The diversion load can be doing something useful such as heating water if there is to be a lot of energy dumped, as can be the case with hydro.
If you use a generator and wish to EQ with it (which makes very little sense to me) then what I suggest is to use a relay on the generator output that disables or modifies the tristar by acting on the battery-sensing wires. I have sometimes used such a relay to insert diode strings into the sensing leads so as to raise the effective PWM voltage and avoid dumping generator power into diversion loads. Or just run the generator to bring the batteries out of a low state to a state of half charge, and do the EQ charging with renewables when they are abundant. A proper EQ charge takes a long time and not very much power, so a generator is very wasteful doing this.
Finally a note on resistor power rating. A one ohm resistor at 60 volts will draw 60 amps and produce 3600 watts of heat. It will do this even if it is rated for 1000 watts. However it will overheat and be damaged and may also be a hazard. Make sure the resistor is working within its safe power rating as well as choosing a resistor (ohms rating) that can dump all the current you produce and not overload the charge controller.
I hope this helps!
Hugh
Hugh,
That was useful. I agree with you that EQing with a generator makes little sense if you have designed a balanced, capable system. Having two sources of renewable power also should help. Nevertheless I liked your relay tip.
Regarding dump loading: I purchased the PWM Tristar45 for the hydro dump control some months ago. Now that I can appreciate resistor power ratings (thanks again), I realize how big of a dump bank I would need to cover my entire system (ten 300W 10 ohm rubber “torpedos” to match my 2200 watts of PV/Hydro). In short, because I was only going to run my Hydro generator at night anyway, I am thinking of using the TS-45 and a smaller dump bank.
No need to reply, I reposted this scenario on the AW&S link above. But overall I think I am pointed in the right direction.
-SP
hi
YOu could consider this product
It’s tricky using a dump load that is too small with hydro. You could fry your battery and that can be dangerous. Maybe consider also using a relay based control to operate a heater that runs on the inverter or to shut the turbine down.
Hugh
Hugh,
Thanks for the reply. It will take me a while to figure out the relay/heater set up. Re the link to the dump bank: Although more attractive than a large bank of rubber ‘torpedos’, it’d would be difficult for me to source this unit (long story). But overall, you give great advice (I realize this is a limited ‘forum’ for this, so thanks). We all appreciate it.
SP
Can I use this high watts resistor on a plug and jack application. In other words. I want to hook up a 3.5 mm plug to a 3.5mm jack running a 12v system. I want to test the number of cycles on them . This is more as a mechanical test for my plugs and jack. plug tip connects to jack tip and sleeve connects to jacks sleeves or shunt. how do i connect to perform electrical testings on them? would these resistors work?
I want to use my electric hot water heater as a dump load for wind generator ( for that matter a pre heater for my hot water demands). The heating element installed by the MFR is a bit much and is rated for 240 VAC rated 4500 watts, so about 19 amps.
This is a bit much for my 12 VDC wind generator. DO you suggest any reliable brand of threaded heating element of 200 – 300 watts, threaded, for use inside an electric hot water tank ??.
Thanks,
SB from USA
Hi
In the USA there are various supplier for example here for water heating elements. In the UK I like TP Fay.
Sometimes you can find grid voltage heaters with multiple elements in them and you can connect them in series instead of parallel so as to reduce the power they use from an inverter and match the power of the wind turbine that way.
I have a dilemma re dump loads. On a wind turbine if the resistance is too low it simply brakes the turbine. In fact I use this in my brakes to gives the turbines a “soft” stop.
On hard braking the turbine creates a lot of heat. This can burn out the turbine if it is constantly stop starting.
I use an MPPT charge controller that I set to 100VDC from the turbine (1500 watts 72 volt coil) The charge controller locks in the 100V and jsut increases current to load the turbine. The charge controller does the MPPT and converts the 100v to battery charge voltage, lets say 50V. The result is a doubling of the current ie say we are generating 1000 watts @ 100v (10amps) then we output 50v @ 20 amps. We set the charge controller to start dumping at 56V (battery volts)
I have 4 x 3.6ohm 1000 watt resistors that I can wire in any way. Obvious choices are .9 Ohm (all parallel) 3.6 Ohm (par/ser) or 14.4 Ohm (all series)
The first two simply stop the turbine and the latter just seems too high.
Can you advise how I get around this dilemma?
hi marc,
There are a few different ways to use the words MPPT and charge controller. For me, the MPPT should operate the wind turbine at a variable voltage so as to optimise the output in varying winds. Low volts in low winds, and higher volts in higher winds. Set at 100 volts (fixed) it achieves little except to match the winding to the battery and you could have made a winding that produces 50 volts and binned the controller.
Turning to the charge controller, the way I normally do this is to divert current from the battery to a dump load. I don’t usually connect the diversion load to the wind turbine so much as to the battery. If you operate a changeover switch, and flip the wind turbine onto dump, then you will likely stall it which might be good, but you stop producing power. So I prefer to dump from the battery, and if possible use PWM to dump just the right amount so that the battery is not being discharged. But where I am using relays I use several small loads and I do discharge the battery a bit in long pulses on/off.
In your case your 3.6 ohm relays will dump 56/3.6=15.5 amps connected directly which is almost a whole kW of power in one heater. That’s a bit rough so I would split them into two series pairs each of which dumps 8 amps or so and operate them with two relays so they dump off the battery when full. I’d prefer to use them for water heating if possible when there is a need for hot water. Each heater will dump about 220 watts in this configuration. So you can dump 440 or 880 watts depending on the relays. Or better still, use a Tristar controller in diversion mode and 3 of the heaters in parallel to give a maximum dump current of about 45 amps.
Thank you admin (Hugh?) for your prompt and detailed response.
The charge controller I use is on my website. Here: http://windturbinesaustralia.com.au/index.php?p=1_2_Controllers
It is the 40amp wind version from Microcare SA.
I initially went with a 48 volt coil (to match the batteries) in the turbine but found the high currents (up to 30 amps at 60 volts) burnt out my coil. I went to the 72 volt coil to
A. Reduce current and therefore heat
B. Reduce line losses from turbine to controller.
The charge controller has an auto mode where it “hunts” for the best voltage as you say above. But it also has a programmable start point. I found the auto mode did not hunt for the best voltage/current set point so I set start at 100V which pretty much halved the current the turbine would have to produce.
Setting and fixing the start voltage point also has a nice advantage as it determines turbine rotation speed so turbine does not run away/over spin in high winds. It sits at 100v and just gets loaded more and more.
The charge controller does use PWM for both battery charging and dump diversion. I have a total of 4000 watts of resistors (4 x 1kw @ 3.6 ohms each) and the turbine maxes out at 1800 watts before furling kicks in, so dump load capacity is not a problem.
I agree 100% with your staged dumping but I am trying to work with what I have.
In summary the issue I have is heat. If the dump resistance is too low and the batteries are fully charged and the wind is strong the PWM constantly pulses the load and the turbine slows dramatically for a short time causing a lot of heat in the coils. This occurs over and over again and eventually the coil just burns out.
Regards,
Marc
WTA
hi Marc,
With reference to using a higher voltage and less current in the stator, this is exactly cancelled out by the higher resistance of the longer, thinner wire in the stator to achieve a higher voltage. Yes, you save on transmission loss, but unless the turbine voltage varies with windspeed, the “MPPT” converter is largely a waste of money in my view.
If your stator is burning out then look to improve the furling and do it sooner. I don’t have problems with stator overheating. Furling is a top priority for me. I focus on low wind energy production, not thrashing the maximum out of the alternator for a minimal gain in kWhours.
If you dump into diversion loads directly off the battery (which I recommend) then the turbine will not be affected at all since it will not know anything about it. The battery voltage is all that the turbine knows about and not what the current it feeds in is used for (charging, user load or dump – all at the same battery voltage – makes not difference to the turbine).
When you say the controller pulses the load and the wind turbine slows that makes me think the controller is putting load directly onto the turbine and not the battery. Maybe it is loading on the AC side of the rectifier? Doesn’t seem like PWM whatever. I suggest you use a tristar diversion load controller (not MPPT) that dumps current off the battery rather than the turbine, if dumping off the turbine is causing you problems. Also work on better furling.
Hugh
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Hugh. Love your work. Thanks for all the info you provide for free. Dump loads are always difficult for my customers. I used to work for Energy Systems and Design in Canada making small water turbines. Diversion loads were always a source of confusion. Thanks for clearing things up. Take care…
Jody Graham