Solar Install; the on-going saga

Sir Liamalot wrote: »

PVC Blade templates here.

Those are some highly impressively quiet blades. Kudos that man!
Alternator is flying at about 200Hz on a free standing mast and other than the vane rattle (play in the rivets) and the cogging hum, it's just a whisper above the wind (sorry no tachometer, I think it's a 24 step rotation).

My traffo is having a rest. Haven't had time to take it into the surgery. After a preliminary investigation I found a fried thermistor (in-rush limiter).



I'm going to have a go at salvaging components off the 110VAC side of the board to get the 220V back up.
It's been running in overdrive (tied to a 45A solar controller). I thought when I was getting a 24v 15A traffo I'd have a 24A @15V charger...which is possible with MPPT but with my PWM controller it's just a 15A charger and a convection heater.

I've seen it produce nearly 17A sometimes so I'm actually impressed it lasted this long. If I can fix it I'm going to have a look at putting a current limiter on it to stop it from frying again. If I can't I, found a new cheap(ish) contender for a mains charger. Not programmable though, no voltage sense leads and not ideal set-points either...better than most all the same.
I can take the frankinductor away, pull out a C/O relay and save five points of contact resistance on the solar module if I change tack and won't have to listen to those infernal bees anymore.

Sir Liamalot wrote: »

The electrolyte density is down to 1.260 per cell

I found this from Crown in my investigations (suspecting a grumpy solar controller next)







I'm not entirely convinced it's so (like they say 12.6v is fully charged :rolleyes:), but I have just watered the batteries so perhaps I'll allow that margin for error for the time being...and not that I let the batteries rest for 24hour either. I've reassimilated the lead dioxide with a deep cycle.

Traffo is dead like dodo. I got the 110V side up for 5 mins on a resurrected 110v site traffo until it blew a line filter cap because I mistook the replacement thermistor with a ceramic capacitor, replaced the blown electrolytic cap and a genuine thermistor and lost the regulator, then gave up.

The replacement if any needs to be current limited. PV modules are current sources this is what the TS expects so anything I put on it will over-current unless it's over-rated which might damage the TS or the batteries are nigh full and then's it's just inrush I have to worry about.

Lost a 3.8A charger too...it gave up the will to live after 14 hours slogging it and the PV came online brandishing a PWM wave in it's vicinity.

The death toll continues;
Tristar: 3 - cheapo mains chargers: 0

Anyone know of a current limited 20ish amp 16V PSU? (not a lab supply....haven't got that kind of real estate in the leky closet).
I'm tempted to quit while I'm behind and buy the Victron except the absorption is too low and the float's too high. Nothing programmable in mains-land for under €250.

I may have to build a 20A current limiter but don't fancy the bees returning. Although on closer inspection of the SMPS it's the MOSFETs (type of gubbins) that are generating the heat I may get away with insulating the internal inductors. hrmmmmm....

Meanwhile I've been thinking of rewiring a 3 phase washing machine motor single phase :eek: and belting it to an alternator for an CV mains-charger dual purpose bench grinder :pac:
...I reckon that'll maybe peak 30% efficient :rolleyes:

That's what I would have thought M. but when I emailed Morningstar previously they are very concerned about being within spec of the controller. The manual advises to only load it to 80% capacity with Isc PV to allow for edging spikes and low temp. up-rating.
That said the manual also says it'll take 130% under FET duress.
I'm suspicious that being that it's tied to a current source it's designed to to grab what it can and run, unlike traditional voltage sources that sit in and around what current they demand. ...correct me if I'm wrong I haven't researched it a whole lot tbh.


It has a wide input range but it's just a big buck regulator really and MPPT is a big buck/boost regulator with compensation for battery SOC.

It'll happily power up at 9V and idly twiddle it's thumbs until it sees a voltage higher than the batteries then buck everything it deems fit up to 125V.

Supply needs to be higher than my temp. compensated equalisation set-point inc. wiring and circuit losses.

Computer PSU max out at 12V? Can any wizardry be done with the 5v and 12v rails to make a 17V output?

Whadya make of this?



Do you think I could parallel two 10A outputs for 20A? Or is that a manufacturer question?

PS. My 3.8A charger dieing may have had more to do with overwork than the TS. Usually solar controllers read battery chargers as a charged battery and back off.

3.8A charger back online.
I read in some forum hitting it might help (tv fix :rolleyes:).
So after repairing broken solder legs on the the mains LC from brutalisation (hitting solid state lekytronics rarely does much good :pac:), it was just the mode switch gave up. Swapped it out and she's good to go.

Tristar; 2 - Cheapo mains chargers; 0 - Sir Liamalot; 1

I've now got ~150% more electrons flowing from my alternator to my house batteries per hour in the Summer, probably more in the Winter because my fridge is now running on a thermostat on the AC element from the inverter, which I've hard-wired through half my "ring main" on self-discriminating mains/inverter sockets (including the one I use for battery charging :pac:).
I can turbo boost my fridge when driving 12v + 230V = 225W :cool:-ing. Soon as fridge is down to temp. thermostat kicks out and fridge runs on 12v only.
The fridge can now feasibly run from PV on selective occasions.
I didn't convert all my sockets because I didn't fancy taking the walls and roof apart and in an effort to leave my dual source powered, triple circuit, 2-way switched overhead lighting well enough alone (here be dragons) there was no easy way to isolate them from 4 sockets. Eh. I've 2 dedicated inverter sockets. 5 auto-selecting and 4 dedicated mains sockets. Close enough.


This is a potentially hazardous circuit for a few reasons.
If you wire it incorrectly it'll neutralise your inverter (easy do with 8 poles). Depending on the inverter isolation I guess you might be able to explode your batteries.
If you break the relay while running an inductive load at full capacity (2300W) I reckon you could get an arc to bridge the contacts and neutralise your inverter.
If your connections/crimps fail it could neutralise your inverter...etc..
I needed to extend a core-set to the relay position. Normally I just pull out the old cable and run a new cable instead. I hate connector blocks. In this case that meant pulling out half the conversion and a third of the roof...as needs must I made the exception and butt crimped this one with a real crimping tool and heat shrink.

I don't really care for solder for a vibratey camper application, I prefer the flexibility of crimps, I think solder makes things rigid and more inclined to break...how and ever I've never seen a solder joint fail on a vehicle all the same...not that I have many.


Everything tested and working!

PS. If you're testing a MSW inverter on a non-RMS multimeter you'll get some funny numbers off the dirty sine wave ~150V-190V AC.

This is kindov impressive for a mains charger (it's a low bar ...small, expensive and Spartan by solar controller standards).

It goes into storage mode after < 12hours (all the manual says is "It is therefore essential to reduce the voltage even further when the battery remains connected to the charger during more than 48 hours.")

Looks like the float current is higher on the "High" algorithm. It's ~ 500mA @ 13.8v. Turning on and off loads doesn't effect the charging stage.
Load Compensation is soft rise, soft fall. Battery fills the gaps to avoid hard switching I guess.

Few more tests to run but they'll be a while.
Equalise current and voltage.
Heat sink temp. at full load.
Who quits absorption earliest TriStar or Victron (my money's on Victron)
I might test this 94% efficient claim if I could be bothered, although if they wanted 95% they could've just made the (12 AWG) charging leads fatter imho.

I'm a little underwhelmed with this Victron in the end.
Just a little though. I was very disappointed that after cycling from 40% DOD and then restarting an new charge cycle it called it a day @ SG 1.250. Then I put the batteries on the TS and it went straight into float too.
That's actually saying a lot though because previously the TS has always outperformed my cheapos.
I got 5 cells up to SG 1.275 last week after 4 days on PV float (13.5V) the last cell was 1.265 and having none of it (yup I spent a week looking for my last 1.6% charge :rolleyes:).
I tried a C20 discharge in an attempt to re-balance the cells after equalisation did nothing and them 6v's are bang on 235Ah.
I also swapped around the batteries so the weaker cell isn't in the middle anymore. Moved the temp sensor to the 0v post that gets the most sun (instead of the previous +6V post )

It's all a bit too overcautious and tight-fisted with the electrons.

Equalisation is set at 15V (25°C); 1 hour :rolleyes: (set-point not listed in the manual just a max of 16.5v)...kinda pointless; my requirements are 15.5V, 3 hours.
I can't just equalise on it either, I have to bulk first and let it run through it's stages. So running it 3 times is just ridiculous. :mad:
Basically just a hot cycle then.

The manual says the EQ charge current is 1.2A and

Victron wrote:

"Some battery charger manufactures recommend pulse charging to reverse sulfation. However, most battery experts agree that there is no conclusive proof that pulse charging works any better than constant voltage charging. This is confirmed by our own tests."

I metered it as a slow current pulse averaging 1.4A.

Temp comp. is 2mV below standard recommended.

Victron wrote:

Ultra high efficiency “green” battery charger with up to 95% efficiency, these chargers generate up to four times less heat when compared to the industry standard.....
...
...Durable, safe and silent
- Low thermal stress on the electronic components.

Victron wrote:

Protection against overheating: the output current will reduce as temperature increases up to 60°C, but the charger will not fail.

Looks like storage kicks in after ~3 hours.

Storage load compensation sits exactly 0mA if you give it long enough on good batteries with a constant/no load.

That's understandable.
From what I've seen discounting Sterling on reliability issues (but not warranty or customer service). You can get twice the charger for half the price with a solar controller and an external current limited supply. That said I've still to make it work.

It's a steady 58% at full load. By the time it reaches 14.6v it's already switching to reduce internal heat so higher volts doesn't improve efficiency.