maplin solar regulator?

[contessaman]

Hi, think Im going to buy this:

http://www.maplin.co.uk/dual-16a-solar-charge-regulator-266145

to fit with my new 60 watt flexible panel.

Any experience of this unit? the idea is for one output to go to my engine battery the other to the domestic bank.

few questions?

will it be adversely affected by the alternators output if this is left permanantly connected?

It looks like when the batteries are charged, it just disconnects the solar panel, rather than dump the current into a giant resistor. Is that okay for the solar panel to sit there in the (sun) with no load on it?

finally, once under sail on a lengthly passage, I want every ounce of power from the panel to go into the domestic bank, to sustain navkit, autopilot and the like. Is there a chance this sort of regulator will waste some of the panels' power in trying to float charge the starter battery, in which case would I be better with 2 of the single battery regulators and a switch in the supply to the starter battery one. that way, when boat left in marina, both banks floated at full charge. on passage at sea only the domestic bank is charged (with the option to manually select starter battery if required of course).

I suppose plan B would be to just charge the domestic bank with solar panel. Since I can always start the engine from domestic bank or both if necessary.

too much choice. Help please!!

 

[vyv_cox]

It looks like a good piece of kit for the money, I may buy one myself, so thanks for the heads up. Reading their description it does appear that the starter battery would be charged if its voltage is lower than that of the domestic bank. But the facility to charge both is very useful. Could you put a switch in the starter charge line for use on passage?

 

[bedouin]

I would be cautious about connecting an alternator up to it without knowing more about the internals. If it contains a shunt regulator then you could end up trying to shunt the entire alternator output! My guess is that it is unlikely to be the case here though - the little it says suggests that it just switches the output to each battery independently.

I wouldn't worry about having the two banks always connected - it should favour the lower charged bank to such an extend as not to cause any problems

 

[noelex]

It is a simple on / off switching regulator. This type of regulator wastes a reasonable amount of power when regulating. Go for a PWM (pulse with modulated) regulator, they are much better and not expensive.
Do you need solar to charge the start bank?

To answer your other questions it will cause problems with the alternator or its regulator and there is no problem with the regulator disconnecting the panels in full sun. Only wind generators need regulators with dump resistors, not solar.

 

[VicS]

I think you will find it is not a regulator in the usual sense of the word. Rather you will find that it simply disconnects the battery when the volts have risen to 14.4 volts and reconnects it when it falls to 13.4 v.
Adequate to prevent overcharging.

Single battery versions also exist as well as a similar gadget that will also supply a load and disconnect that if the battery volts falls below some predetermined value.

Not to be confused with pulse width modulation in which the charging rate is actually regulated as the battery charges, or with maximum power point tracking regulators.

 

[contessaman]

thanks for the responses.

I guess the alternator problem could be resolved by switches to disconnect the entire solar charging system while engine running. bit of a nause but simple enough.

noelex, you mention cheap PWM regulators? any chance you have a link to somewhere selling one? I have been warned against a lot of the cheap ebay ones from china. either not actually being PWM or potentially spontaneously combusting.

vicS, you mention load. Is that what I have seen on some of the ebay so called PWM regulators? they have six contacts on them, 2 for battery, 2 for panel and last 2 have picture of bulb and say 'load' but I do not know what this is for?

ta

 

[noelex]

thanks for the responses.

I guess the alternator problem could be resolved by switches to disconnect the entire solar charging system while engine running. bit of a nause but simple enough.

There is really no need to do this

.

noelex, you mention cheap PWM regulators? any chance you have a link to somewhere selling one? I have been warned against a lot of the cheap ebay ones from china. either not actually being PWM or potentially spontaneously combusting.

I think the best cheap regulators are Gensun. These are PWM and MPPT

http://www.genasun.com/solarproducts.shtml

vicS, you mention load. Is that what I have seen on some of the ebay so called PWM regulators? they have six contacts on them, 2 for battery, 2 for panel and last 2 have picture of bulb and say 'load' but I do not know what this is for?

ta

For a boat you will generally leave the load wires on simple regulators disconnected.
The load wires are used for features like battery disconnect at low voltage, but they will only handle small currents so they are not much use on boat, but some sophisticated regulators can be programed to do useful things via these terminals like turn an anchor light on at dusk, or activate a relay when the batteries are full (the relay can say start the fuel polishing system)

 

[VicS]

thanks for the responses.

I guess the alternator problem could be resolved by switches to disconnect the entire solar charging system while engine running. bit of a nause but simple enough.

noelex, you mention cheap PWM regulators? any chance you have a link to somewhere selling one? I have been warned against a lot of the cheap ebay ones from china. either not actually being PWM or potentially spontaneously combusting.

vicS, you mention load. Is that what I have seen on some of the ebay so called PWM regulators? they have six contacts on them, 2 for battery, 2 for panel and last 2 have picture of bulb and say 'load' but I do not know what this is for?

ta

There should be no need to disconnect the solar system when the engine is running.
Just to clarify a possible misunderstanding these regulators are suitable only for solar charging control. They must not be used to control charging via the alternator.

The additional two terminals with the bulb symbol are for supplying a small load continuously with the capability of disconnecting it if the battery volts falls below some critical value rather than running the battery completely flat.

 

[contessaman]

There should be no need to disconnect the solar system when the engine is running.
Just to clarify a possible misunderstanding these regulators are suitable only for solar charging control. They must not be used to control charging via the alternator.

The additional two terminals with the bulb symbol are for supplying a small load continuously with the capability of disconnecting it if the battery volts falls below some critical value rather than running the battery completely flat.

got it. so somebody may use it to power a lighting circuit or similar without taking the battery into deep discharge. I have no need for this but it should not preclude me from buying a charge regulator that has one, now I know what its for and that one does not need to use it (thanks!)

roger that re: alternator, dont worry I wont be touching my alternator circuit. I was more worried about the circa 14.4volts plus any ripple at the battery somehow damaging the solar unit charge unit.

Just a final word on effeceincy and PWM vs this maplin switching type. I have had a look at that genasun website, they are still quite a lot more expensive than the maplin one. I need some more convincing to splash out 3 or 4 times the cash of the maplin one. somebody talk me into it...

If I can make a further statement about my useage. I perhaps dont care if my solar charging system is not hugely efficeint at re-charging a deeply run down battery bank. even if half of my 60 watts is wasted, that should still keep the batteries topped up when Im not at the boat.

Im more interested at sustaining them when under way. marine pc, VHF and wheelpilot probably average out at 2.5 amps. So during daylight if the panel can come close to matching that-great. You might say that whenever Im on the boat, I will be taking enough power with systems at sea or eberspacher in harbour that I dont need a regulator at all. I could permanently connect the panel to the battery. Obviously that just woulndt do when I left the boat and I'd boil my battery bank away. hence why I thought the switching type was fine.

Unless the PWM does something clever like actually coming close to the stated 60watt of the panel by turning excess voltage into more current then I cant justify the price. perhaps....???

 

[V1701]

I have two of the inexpensive (about £12 each from a UK based supplier) PWM regulators, they are absolutely fine. I have two panels, a 40w & a 20w, in summer there's enough to keep instruments going and also charge (via cig lighter socket) my phone, netbook & HH VHF. In winter there's enough to keep the LED lights going in the evening. I have two 110AH batts & live on the boat...

 

[noelex]

Unless the PWM does something clever like actually coming close to the stated 60watt of the panel by turning excess voltage into more current then I cant justify the price. perhaps....???

There is a big difference between the effeciency of a simple on off regulator like the Maplin one and a PWM regulator.
There are many cheap PWM available on ebay and they are worth considering. The quality is not great, but the Maplin regulator appears to be only cheaply made.
The Genasun regulators are good quality both PWM and MPPT. The MPPT is what converts excess voltage to more current, but the MPPT only makes a small difference.

 

[contessaman]

There are many cheap PWM available on ebay and they are worth considering

like this?

http://www.ebay.co.uk/itm/12V-10A-P...983?pt=LH_DefaultDomain_0&hash=item3f10222d87

or this:

http://www.ebay.co.uk/itm/PWM-Solar...20915936810?pt=UK_Gadgets&hash=item336f9dae2a

Im sure some people on this forum said a while back that these ebay ones were dodgy. some not even really PWM and are crude ones with power transistors that get red hot.

perhaps at the price I should give one a go, see how it works at home before risking it on the boat.

Can you please just help me understand something. (by the way im not arguing im just trying to get it all clear in my head so I make the right choice!)

I accept the maplin one is crude - just switching the panel in and out. but lets assume a moment in time when its switched 'in' -that must be applying the full power of the panel to the system. How is PWM better than this? it cant make power (excluding the MPPT you mention), are we talking about having a smart charge with bulk, apsorption and float stages ( a bit like a smart shore power unit or digital alternator regulator) so the improvement is not the charging current but the fact that the stepped charge actually takes the batteries upto 100% capacity whereas a dumbass solar panel or cheapo halfords car battery charger actually only ever acheives say 90% charge. Is this what PWM regulators offer?

thanks for your help

 

[maby]

I used one all last year with a 12w panel on our old Hunter Ranger to keep the two batteries topped up and it worked fine. On the few occasions that we left the boat off shore-power with either or both batteries less than fully charged, we always came back the following week to find them topped up.

 

[noelex]

l

Can you please just help me understand something. (by the way im not arguing im just trying to get it all clear in my head so I make the right choice!)

I accept the maplin one is crude - just switching the panel in and out. but lets assume a moment in time when its switched 'in' -that must be applying the full power of the panel to the system. How is PWM better than this? it cant make power (excluding the MPPT you mention), are we talking about having a smart charge with bulk, apsorption and float stages ( a bit like a smart shore power unit or digital alternator regulator) so the improvement is not the charging current but the fact that the stepped charge actually takes the batteries upto 100% capacity whereas a dumbass solar panel or cheapo halfords car battery charger actually only ever acheives say 90% charge. Is this what PWM regulators offer?

thanks for your help

The Maplin regulator when its switched in will be as efficient as a PWM regulator, but once the voltage reaches 14.4V even briefly the Malpin regulator turns off the solar panel completely until the voltage drops to 13.4V. During this time there will be no input from the solar panel at all. Marine batteries can hold a surface charge for a long time and the solar output during this time is wasted.
With a PWM regulator when the voltage reaches 14.4v the regulator will hold the voltage at this level by blocking at first a small amount of the solar panel output. Thus utilizing 90% of the solar output when the Malpin regulator would be using zero. As the battery becomes more charged the PWM regulator will block more of the solar panel output to maintain the voltage, but it never drops to zero.
The better PWM regulator then change to a float voltage when the battery is fully (or nearly fully) charged.

 

[V1701]

like this?

http://www.ebay.co.uk/itm/12V-10A-P...983?pt=LH_DefaultDomain_0&hash=item3f10222d87

or this:

http://www.ebay.co.uk/itm/PWM-Solar...20915936810?pt=UK_Gadgets&hash=item336f9dae2a

Im sure some people on this forum said a while back that these ebay ones were dodgy. some not even really PWM and are crude ones with power transistors that get red hot.

perhaps at the price I should give one a go, see how it works at home before risking it on the boat.

Can you please just help me understand something. (by the way im not arguing im just trying to get it all clear in my head so I make the right choice!)

I accept the maplin one is crude - just switching the panel in and out. but lets assume a moment in time when its switched 'in' -that must be applying the full power of the panel to the system. How is PWM better than this? it cant make power (excluding the MPPT you mention), are we talking about having a smart charge with bulk, apsorption and float stages ( a bit like a smart shore power unit or digital alternator regulator) so the improvement is not the charging current but the fact that the stepped charge actually takes the batteries upto 100% capacity whereas a dumbass solar panel or cheapo halfords car battery charger actually only ever acheives say 90% charge. Is this what PWM regulators offer?

thanks for your help

Mine are two of the second type you link to, as I say they are fine...