How much solar do you have?

[Stemar]

I had one of these on Jissel

Dual Battery Controller 10A - 12V/24V - Sunshine Solar - Sunshine Solar Limited

Cheap and cheerful, at under £40, but it was still working finewhen I sold the boat after better than 10 years. Nothing clever, I had it set up to charge the starter battery until it burped, then work on the domestic, on the basis that the starter battery would rarely need much, but I really wanted to be able to start the engine in the event of problems, but it spent most of its time working on the domestic one.

 

[Refueler]

I'm more used to industrial 'PWM' controllers which control things like efficient motor drives.
PWM DC-DC convertors can be sophisticated, efficient things. And very cheap too.
There's generally an inductor or transformer in there to convert voltage.

For sure, I'm not expecting a lot, I just want the solar to shut off before overcharging the battery or over-volt stressing anything connected to it.
My cheap solar controller seems to have killed a 12V to USB convertor.

Fair enough ... obviously I come across PWM / PCM / PAM with reference to Radio Control and other areas with motor control etc.

I have noted a slightly higher sustained voltage across my batts - but not stressed levels ... I have a manual batt check meter I can switch A - Off - B to see battery levels ... on installation - I checked against good DVM and it agreed within reasonable decimal ...
I also have readout on my plotter of supply voltage ...

I'd be interested to understand why it would destroy your USB convertor ...
Unlike PR - I would like to understand why - and that would also be good for others to understand I reckon ..

I have had various items fail on board .. in car ... at home ... I do try to find out why and usually its just failure of the item itself ... especially when it comes to such as adaptors ...

There are at least two USB outlets powered from the batterys on my boats and the high solar controller rate has not caused any problems - SO FAR !

I admit that usually myself and others who are on board - use car chargers based on ciggy plugs into power sockets - not USB based. So maybe its a problem I am yet to see ?

 

[Refueler]

I had one of these on Jissel

Dual Battery Controller 10A - 12V/24V - Sunshine Solar - Sunshine Solar Limited

Cheap and cheerful, at under £40, but it was still working finewhen I sold the boat after better than 10 years. Nothing clever, I had it set up to charge the starter battery until it burped, then work on the domestic, on the basis that the starter battery would rarely need much, but I really wanted to be able to start the engine in the event of problems, but it spent most of its time working on the domestic one.

That's gonna upset a few people !!

 

[geem]

I had one of these on Jissel

Dual Battery Controller 10A - 12V/24V - Sunshine Solar - Sunshine Solar Limited

Cheap and cheerful, at under £40, but it was still working finewhen I sold the boat after better than 10 years. Nothing clever, I had it set up to charge the starter battery until it burped, then work on the domestic, on the basis that the starter battery would rarely need much, but I really wanted to be able to start the engine in the event of problems, but it spent most of its time working on the domestic one.

I had one of those. It failed and cooked my Domestic batteries whilst we left the boat for 3 months.

 

[Kelpie]

I had one of these on Jissel

Dual Battery Controller 10A - 12V/24V - Sunshine Solar - Sunshine Solar Limited

Cheap and cheerful, at under £40, but it was still working finewhen I sold the boat after better than 10 years. Nothing clever, I had it set up to charge the starter battery until it burped, then work on the domestic, on the basis that the starter battery would rarely need much, but I really wanted to be able to start the engine in the event of problems, but it spent most of its time working on the domestic one.

I also had one of these on my previous boat, paired with the cheapest possible 50w rigid panel off eBay. Worked perfectly well for about five years until I sold the boat.
Slightly concerned by Geem's experience of the same unit.

 

[Refueler]

I also had one of these on my previous boat, paired with the cheapest possible 50w rigid panel off eBay. Worked perfectly well for about five years until I sold the boat.
Slightly concerned by Geem's experience of the same unit.

Even Rolls Royce fail .....

Like every item known - there are failures and successes ... unfortunately - the failures get more coverage than successes. Plus the more of an item that gets sold - the more failures get known about - even though in actual % numbers of items sold vs failed - most likely no worse than other brands - but the apparent view is that its bad.

I wonder how many reading such threads as this - actually have similar controllers and are keeping quiet - avoiding the flak ???

 

[B27]

I had one of those. It failed and cooked my Domestic batteries whilst we left the boat for 3 months.

Leaving something unsupervised for 3 months is probably a long way from what the designer of the unit was asked for.

Half the world is using cheap solar stuff to power lights and things which get used every day.
I suspect the charge cycles are intended for that kind of thing and floating a boat battery for months with no load is beyond the capability of the unit.
Just as it's beyond run of the mill 230V 'automatic chargers'.

 

[PaulRainbow]

Leaving something unsupervised for 3 months is probably a long way from what the designer of the unit was asked for.

Half the world is using cheap solar stuff to power lights and things which get used every day.
I suspect the charge cycles are intended for that kind of thing and floating a boat battery for months with no load is beyond the capability of the unit.
Just as it's beyond run of the mill 230V 'automatic chargers'.

That's ridiculous!

Solar controllers should work OK for years, unsupervised. How does not being there make it fail ? If you're in attendance, what are you supposed to do with the controller, check it is still working as it should be, every hour, every two hours ?

Millions of boats get left unattended for months on end.

 

[geem]

Leaving something unsupervised for 3 months is probably a long way from what the designer of the unit was asked for.

Half the world is using cheap solar stuff to power lights and things which get used every day.
I suspect the charge cycles are intended for that kind of thing and floating a boat battery for months with no load is beyond the capability of the unit.
Just as it's beyond run of the mill 230V 'automatic chargers'.

What?
If you install one any boat, do you turn it off before you go home? It's an unsupervised install and operation. How can it be beyond the capability of the unit? It doesn't know what happened with the batteries the day before. It just wakes up when the sun shines and does its thing. In my case it didn't. It failed in a catastrophic way and destroyed my batteries.
I now use Victron kit on my boat. It's well worth the extra money if you have an expensive battery installation. I have learnt that lesson

 

[oilybilge]

70 watts with a Victron controller. It lives between the hatch runners but can be placed anywhere on the cabin roof. Plenty for the laptop, phone, ipad, autopilot and 110ah battery. When I visit a marina I don't even bother plugging in.

 

[dankilb]

That's ridiculous!

Solar controllers should work OK for years, unsupervised. How does not being there make it fail ? If you're in attendance, what are you supposed to do with the controller, check it is still working as it should be, every hour, every two hours ?

Millions of boats get left unattended for months on end.

+1

Our boat had the same knackered boxy old-school mppt running the two 130w panels non-stop since 2002 afaik. Since replacing it with a new Victron a year ago that had run uninterrupted. What’ll float my LA batteries without it when the boat’s not being used?

 

[noelex]

This is our wind gen on the transom, the pylon is secured to the aft of the bridge deck transom with large 'U' bolts and big backing plates. The wind gen does not produce any shadow over the solars, but the boom does . Since then we added a single 200 watt panel to the roof, in the obvious 'empty' space, and a roving 250 watt panel. I cannot recommend flexible panels - but they offer the sensible way to use the saloon roof and still allow work on the main. Solid panels are better, which could be mounted on the davits - except we hold the kayaks on the davits
View attachment 163199

Jonathan

I understand that you sold your catamaran some time ago, but if you were redoing the electrical system on a similar vessel you would likely install solar panels over the davits (with room for kayaks underneath) or even on an arch across stern. This is less susceptible to shade from the boom and mainsail than the cabin top and cheaper, longer lasting, rigid panels can be used.

New cruising catamarans seem to use both locations (stern and cabin top) to mount large solar arrays and this can be a great solution to generating large amounts of electrical energy.

If a wind generator is installed often it will be causing shadows on the panels.

That is not to say that wind generators are not worth installing, but when estimating the energy they will contribute make sure you factor in the reduction in solar panel output, unless you are one of the rare boats (such as some ketches) where there is an installation option where this is not a factor.

 

[B27]

What?
If you install one any boat, do you turn it off before you go home? It's an unsupervised install and operation. How can it be beyond the capability of the unit? It doesn't know what happened with the batteries the day before. It just wakes up when the sun shines and does its thing. In my case it didn't. It failed in a catastrophic way and destroyed my batteries.
I now use Victron kit on my boat. It's well worth the extra money if you have an expensive battery installation. I have learnt that lesson

A lot of these controllers seem to have some sort of minimum absorption charge of an hour a day, which is fine for an automatic lamp, not fine for a boat which is not in use.

It's similar to having a motorbike laid up for winter, you want a charger which is made for the purpose.

Even a lot of the Victron kit is primarily designed with a lamp load.
If you are using stuff differently from what the designer had in mind, take care.

 

[dankilb]

A lot of these controllers seem to have some sort of minimum absorption charge of an hour a day, which is fine for an automatic lamp, not fine for a boat which is not in use.

It's similar to having a motorbike laid up for winter, you want a charger which is made for the purpose.

Even a lot of the Victron kit is primarily designed with a lamp load.
If you are using stuff differently from what the designer had in mind, take care.

Victron MPPTs are absolutely designed for this and if not, then it’s bloody lucky they accidentally produced something that seems to be doing the job of ‘maintaining’ the batteries in pretty much most yachts I see/sail now. I get that a dedicated mains charger has its place, but I don’t leave shorepower connected! Also I live 10 mins from the boat and there’s always some loads (security, wifi, etc.) and then loads vary when I’m on the boat etc.

So still, no sorry, still don’t get it.

 

[dankilb]

automatic lamp

And what’s this btw? Sure we’re actually talking about boats here?!

 

[B27]

And what’s this btw? Sure we’re actually talking about boats here?!

We were actually talking about mass market 'solar controllers', the majority of which are in use in non-boaty applications.
China and the East generally have a huge home market for this kind of thing.
Sold by the million which is why they are cheaply available.

 

[noelex]

Maybe you are expecting too much. You'll only get the full 50w under ideal conditions- absolute full sun, low temperature, and a half full battery able to gobble up the amps.
My main array is 930w, so in theory I should be seeing 77.5A at 12v. In practice it tops out at about 50A most of the time.

A good test for how well the solar panels and the system overall is performing is to look at the peak output. If everything is working well and you are in a location with good solar insolation you should be seeing this peak output coming very close to the STC rating of the panel.

Top quality panels and controllers if installed correctly can exceed their rating. The best I have seen is 429w from one of my 335w panels. This is exceptional and recorded in a location with excellent solar insolation, but even in the UK in summer you should occasionally be seeing the rated output or very close to this.

These peak outputs will only be brief (usually when there is cloud edge effect) but they are an important indicator that all is well with the system.

 

[PaulRainbow]

A lot of these controllers seem to have some sort of minimum absorption charge of an hour a day, which is fine for an automatic lamp, not fine for a boat which is not in use.

It's similar to having a motorbike laid up for winter, you want a charger which is made for the purpose.

Even a lot of the Victron kit is primarily designed with a lamp load.
If you are using stuff differently from what the designer had in mind, take care.

This is just more nonsense.

 

[geem]

A lot of these controllers seem to have some sort of minimum absorption charge of an hour a day, which is fine for an automatic lamp, not fine for a boat which is not in use.

It's similar to having a motorbike laid up for winter, you want a charger which is made for the purpose.

Even a lot of the Victron kit is primarily designed with a lamp load.
If you are using stuff differently from what the designer had in mind, take care.

That's nonsense. Those PWM controllers are cheap with limited functionality. You get what you pay for. It was several years ago. We are now fully victron. equiped. Victron MPPT controllers are fully programmable. You can minimise absorbtion time within the controllers using adaptive absorbtion settings.

I have moved on from lead domestic batteries as well. It's no longer an issue for me. We do however, keep the generator and our old lead bank ( soon to be removed) on float with a pair of Victron B2B chargers. They give you a proper 3 stage charge profile. As do my Victron MPPT chargers. As soon as the old lead bank is off the boat, the engine battery will get its own B2B. I will build and install a second lithium battery at the same time.

 

[geem]

A good test for how well the solar panels and the system overall is performing is to look at the peak output. If everything is working well and you are in a location with good solar insolation you should be seeing this peak output coming very close to the STC rating of the panel.

Top quality panels and controllers if installed correctly can exceed their rating. The best I have seen is 429w from one of my 335w panels. This is exceptional and recorded in a location with excellent solar insolation, but even in the UK in summer you should occasionally be seeing the rated output or very close to this.

These peak outputs will only be brief (usually when there is cloud edge effect) but they are an important indicator that all is well with the system.

Agreed. Today we have peaked at 748w on a 720w set of 4 panels. These are cheap panels bought in a Chinese electrical shop here in the Caribbean a few years ago