MPPT VS PWM

[hilldweller]

The worst I have seen was 2.2amps - 4.10amps - 4.08 amps side by side simultaneous tests across the three panels

Just to clarify - is this one controller connected to one panel and all three panels then connected to you leisure bank ?

 

[camoyboy]

Another vote for the Votronic MPPT controllers, plus there is the trickle charge for the cab battery with 1 lightweight cable. No need for a battery master or similar.

Colin

 

[eddie]

We have three 150w panels, all identical , on the camper, they are all wired the same to three wall mounted regulators. The three regulators are connected to two 10mm diameter studs, one pos one neg which in turn are connected to the battery bank (6 x 135Amp) We used 25mm2 multi flex cable, to avoid too much voltage drop.

Whilst all of my usage is monitored by a Victron BMV 700 battery computer I can simply connect three meters in series to monitor what the individual panels are producing

Its all good fun playing with stuff like this

 

[eddie]

Another vote for the Votronic MPPT controllers, plus there is the trickle charge for the cab battery with 1 lightweight cable. No need for a battery master or similar.

Colin

Ah but you still have the labour to run the extra wire, and in the dark depths of Winter you may have little or no solar activity, Battery Master will still share the quiescent drain on the engine battery with the leisure battery, when a dual solar regulator isn't producing anything

Same as under cover storage

 

[chaser]

this is mine on a dull rainy day with compressor fridge on full time with just one 100 watt panel

^{_{Subscribers  do not see these advertisements}}

 

[eddie]

Interesting, Eddie, but what do those figures mean? I assume they are the output from three different controllers, but which ones&types? Have you compared a Victron model alongside a Votronic?

The measurement I’m interested in is the power that can be obtained from a panel at various levels of incidence, but no-one seems able to provide it.
All panels will work to a degree but some actual data would be useful to determine what size to get.

We have the Alden Phenix (sic) on another of our vehicles and that is, according to Alden, an average of five times more efficient that a conventional flat panel of the same size (100 watt) We did make some comparison tests ages ago with a Alden 100w flat panel "Jury rigged" on the roof and left the van in the middle of the car park. The trouble is we picked a fantastic day to play so both systems worked superbly and we got bored, sun blind and sun stroked so went off to get cold beers lol

 

[hilldweller]

We have three 150w panels, all identical , on the camper, they are all wired the same to three wall mounted regulators. The three regulators are connected to two 10mm diameter studs, one pos one neg which in turn are connected to the battery bank (6 x 135Amp) We used 25mm2 multi flex cable, to avoid too much voltage drop.

Then I suggest your quoted figures are maybe flawed. The "duff" one down at 2A might just have a threshold 0.1V ( or so ) down on the other two so seeing a near charged bank is backing off. Assuming 3 identical/clean panels is a touch suspect.

Or you may be bang on.

Somewhere on here @Techno posted a simulation he did in his garden, I can't find it now but I recall he made a really good stab at side by side testing.

 

[funflair]

Due to constant variation of the suns brightness, you would need a laboratory set up to produce accurate results. However I noticed a maked differance between my previous good quality MPPT regulator and the new Votronic one I just fitted and reckon it was well worth the £160.
Previously in Spain with 200 watts of panels the best I got during March was 95 watts, my current setup is 300 watts of panels with the Votronic unit and this March I often achieved 160 - 170 watts, that relates to a 15 - 20% increase.

I had two systems fitted side by side one with MPPT votronic and the other with PWM, the PWM was always 25% to 30% behind, changed the PWM to another MPPT votronic again and "bingo" the two outputs match each other so that is me convinced.

Martin

 

[eddie]

Then I suggest your quoted figures are maybe flawed. The "duff" one down at 2A might just have a threshold 0.1V ( or so ) down on the other two so seeing a near charged bank is backing off. Assuming 3 identical/clean panels is a touch suspect.

Or you may be bang on.

Somewhere on here @Techno posted a simulation he did in his garden, I can't find it now but I recall he made a really good stab at side by side testing.

I have a 2600 watt inverter on board which we turn on when testing to drag the voltage down, normally about 30 minutes or so prior

I know that our set up isn't scientific, but it does tend to expose most flaws

 

[Lenny HB]

Somewhere on here @Techno posted a simulation he did in his garden, I can't find it now but I recall he made a really good stab at side by side testing.

I was using the same regulator as Techno but I changed to the Votronic as it is far better at giving a proper 3 stage charge to Gel batteries and found the Votroinic overall performance was a lot better but it is twice the price.

Also like Eddie when carrying out any performance checks I always load the batteries and discharge then a bit first.

^{_{Subscribers  do not see these advertisements}}

 

[Minxy]

You do seem to have a habit of having to have the last word Mrs.

... only if its right!

 

[Lenny HB]

i have just set up a 100w solar panel with this controller Amazon product ASIN B075XFLVPYand fitted a compressor fridge although i havent used this setup in anger yet, just standing in the yard with the fridge on in rainy uttoxeter weather , its keeping the fridge working and by 10 o clock its showing the batterys at 13. 8 volts.
seems ok to me.

You will not achive anything like the max out of your panels with a 24 quid regulator, it will top up the batteries but if you camp off grid and rely on your batteries its well worth spending some dosh on a decent regulator.

 

[Richard n Ann]

Our Votronic 250 is great bought it because it's expensive, the best controller money can buy . Oh and it charges the starter battery so there's no problems using the van radio.

If you buy cheap, you buy twice.

 

[Ivory55]

With the black art of 12 volt you can understand why some stay only on sites and use EHU. I must admit I read it all but understand little. Haha

 

[funflair]

With the black art of 12 volt you can understand why some stay only on sites and use EHU. I must admit I read it all but understand little. Haha

It's simple don't take out more than you can put back in OR even safer if you can't put it back in don't take it out in the first place.

Martin

^{_{Subscribers  do not see these advertisements}}

 

[Minxy]

Dave's already told us what we need to know. He has two panels and needs a new regulator.

Dave said his controller needs replacing....and asked for suggestions as to which type.

Silly me! Must remember that threads must stick strictly to the subject matter and never ever veer off and that I'm not allowed to make an alternative suggestion ... yeah right ... how about also 'chastising' the others that have suggested alternatives too ... nah, just kick me it seems!

 

[eddie]

Silly me! Must remember that threads must stick strictly to the subject matter and never ever veer off and that I'm not allowed to make an alternative suggestion ... yeah right ... how about also 'chastising' the others that have suggested alternatives too ... nah, just kick me it seems!

Who is "kicking who?" I only quoted your post that said:

Not strictly untrue though ... as with all things it depends on the existing set-up and what's required.

@ShiftZZ had said he already has two panels and needs a replacement controller. So it didn't depend on the existing set up! We knew!

... only if its right!

Damn I must have missed that post!

 

[Lenny HB]

It's simple don't take out more than you can put back in OR even safer if you can't put it back in don't take it out in the first place.

Martin

Easy, just sit in the dark.

 

[hilldweller]

You do seem to have a habit of having to have the last word Mrs.

She may wield and axe and a saw but she is still a woman.

 

[Techno]

I like a quiet life these days

^{_{Subscribers  do not see these advertisements}}

 

[Minxy]

The problem with forum posts means that sometimes you tend to have multiple conversations and answers to one post can be taken as meaning a reply to another ...

The title of the thread is MPPT or PWM ... I gave my 'alternative' suggestion which is relevant to Dave as he could get a PWM regulator and stick on another panel if he wants, rather than shell out for an expensive MPPT one which may give him more input but no as much as an extra panel - at the time we didn't know that he didn't have space for anther one.

Anyway, I'll leave it to you lot to keep going on about this, I'm outta here.

 

[eddie]

The problem with forum posts means that sometimes you tend to have multiple conversations and answers to one post can be taken as meaning a reply to another ...

The title of the thread is MPPT or PWM ... I gave my 'alternative' suggestion which is relevant to Dave as he could get a PWM regulator and stick on another panel if he wants, rather than shell out for an expensive MPPT one which may give him more input but no as much as an extra panel - at the time we didn't know that he didn't have space for anther one.

Anyway, I'll leave it to you lot to keep going on about this, I'm outta here.

 

[hilldweller]

I like a quiet life these days

So what was that test you photographed, on a sunny day. I'd like to see it again just to remember what a shadow is.

 

[eddie]

I'd like to see it again just to remember what a shadow is.

A Former self?

 

[bigtwin]

...... just to remember what a shadow is.

Hank Marvin?

Ian

^{_{Subscribers  do not see these advertisements}}

 

[johnp10]

More confusing by the minute:

I have a single 120w panel, two 110 batteries.
Controller? Dunno, really don't care, what the guy fitted, it works.
PWM, I believe.

Why would I need to know what sort of controller is fitted?
Are 13 PWM volts inferior to 13 MPPT volts?
They both work the same, lights burn as bright, TV works the same.
​

I see things simply:
I use power during the daytime / evening.
Batteries are reading +13v by mid morning next day.
As far as I'm concerned, that's it.
What else is there?

Also, I've never known a starter battery run down to discharge even when stood over the winter.
Just needs a short run up every fortnight or so.
That said, what's the point of being able to charge the starter battery?

Just asking.

 

[hilldweller]

Batteries are reading +13v by mid morning next day.
As far as I'm concerned, that's it.
What else is there?.

Nothing at all.

Well, unless the weather is crap and the batteries are not at 13V at dusk when a better controller might have got them there.

 

[johnp10]

Nothing at all.

Well, unless the weather is crap and the batteries are not at 13V at dusk when a better controller might have got them there.

So it's just about quicker charging?

 

[hilldweller]

So it's just about quicker charging?

More like extracting a little bit more electricity from the panel/s in poor conditions.

 

[funflair]

More confusing by the minute:

I have a single 120w panel, two 110 batteries.
Controller? Dunno, really don't care, what the guy fitted, it works.
PWM, I believe.

Why would I need to know what sort of controller is fitted?
Are 13 PWM volts inferior to 13 MPPT volts?
They both work the same, lights burn as bright, TV works the same.
​

I see things simply:
I use power during the daytime / evening.
Batteries are reading +13v by mid morning next day.
As far as I'm concerned, that's it.
What else is there?

Also, I've never known a starter battery run down to discharge even when stood over the winter.
Just needs a short run up every fortnight or so.
That said, what's the point of being able to charge the starter battery?

Just asking.

Are 13 PWM volts inferior to 13 MPPT volts?

I guess the simple answer is YES if you get more amps with one of them.

Batteries are reading +13v by mid morning next day.

You need to tread your voltage when the solar is still in bed to get an accurate idea of real voltage.

That said, what's the point of being able to charge the starter battery?

It allows you to start the van when you need to.

Well you did ask

Martin

^{_{Subscribers  do not see these advertisements}}