Solar Controller Settings

Ammonite

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I have a 60w solar panel connected to two 110ah domestic 12v sealed batteries via a photonic 10amp controller. My question relates to the out of the box settings for sealed batteries which are a fair bit higher than my Dometic 20amp charger which is set at 13.8v max and the alternator which charges at 14.4v. The controller settings are as follows. Should i leave well alone or change any of them?

Boost duration 120mins
Equalise duration 120mins
Over volt disconnect 16v
Over volt reconnect 15v
Equalize charging volt 14.6
Boost charging volt 14.4v
Float charging volt 13.8v
Boost reconnect charge volt 13.2v
Charging limit voltage 15v

The last couple of times ive popped down to the boat the batteries have been sat at 15v
 

Graham376

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Assuming your batteries are branded, what does the data sheet say about charging voltages? 15 volts is too high if they're fully charged, when you visit how long have they been on solar charge, hours or days? The 20 amp charger (max 13.8v) seems to be set at float rather than bulk charge rate.
 

Ammonite

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Given the settings in my initial post should I ever see a voltage of more than 14.6v i.e. the out of the box equalize charging voltage. Does the fact that i have seen 15v on my nasa bm1 and the controller mobile app mean i have a duff controller? Id assumed the boost and equalise functions would push the voltage up to 14.4/14.6 and then it would fall to 13.8v where it would sit until the sun goes down and the voltage drops back below 13.2v and the cycle starts again the next morning (im assuming the batteries arent being used in this scenario)

Ive pulled the fuse for now just in case although the max charging limit is set at 15v as standard for sealed batteries. I just cant get my head around how it can get higher than the 14.6 equalize voltage but this is my first go with solar
 
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Ammonite

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Assuming your batteries are branded, what does the data sheet say about charging voltages? 15 volts is too high if they're fully charged, when you visit how long have they been on solar charge, hours or days? The 20 amp charger (max 13.8v) seems to be set at float rather than bulk charge rate.

Ive tried googling the data sheet but havent managed to find it. They are Lucas ultra deep cycle leisure batteries so bog standard really. I think you are right about the charger but im on a swinging mooring so its not on that often and the alternator takes them up to 14.4v. I'll play with the dip switches when i get a moment. The solar panel is permantely connected (or was until i pulled the fuse) so without shore power they will drop to 12.8v overnight and then go through a full boost/equalize/float each day. Im assuming it was during the 14.6v equalize phase that i checked the voltages today but still dont understand why it was reading 15v unless the 14.6v is an average reading with the max set to 15v? I realise that a full equalize should only be done periodically but thats when you are using 15+v which is why im guessing the equalise default for the controller is 14.6v
 

Graham376

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I don't understand some of the settings you list (I have Victron SmartSolar which is different) but hopefully, someone with more knowledge will come along. In the meantime, I would reduce the disconnect voltage and charging limit voltage to 14.4 volts and see what happens.
 

William_H

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I find it a bit surprising that you have batteries at 15volts purely from the solar panels. Given that you have big battery bank and just 60w of solar. The solar panels will at a max give 3 amps into the 2 batteries. I would wonder about the accuracy of your volt meter. Try another meter. Remember that any solar controller can in the end only limit the charge into your batteries. So all those lovely numbers are only a max ie if batteries are small and solar very powerful. In reality a small solar panel will simply do what it can to pump current in but never getting to fully charged battery state.
So I dunno ol'will
 

Ammonite

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Thanks Will. The batteries are in good nick and my nasa bm1, the controller (it has its own wifi and app which enables me to monitor the voltage) and my multimeter all give the same voltage within 0.1v. The values im quoting are after a few days with everything switched off except a few mA being used by the bm1 and controller. Prior to fitting the panel the voltage would generally be 12.7v even after 2-3 weeks away from the boat. Now im seeing voltages up to 15v but i think this is during the 120 minute supossed 14.6v equalisation period after the 120 minute 14.4v boost before it switches to the 13.8v float and then falls to 12.8v overnight. The max current ive seen from the panel is 1.8amp so far (winter for us)
 

Ammonite

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Ive checked with an engineer at photonic and the controller is working exactly as it should. On the ocassions ive seen 15v during the equalise phase its been a clear sunny and most importantly cool morning. The controller has a temperature algorithn that ramps up the charging voltages a little when its cold (batteries being harder to charge in cold weather and the solar panel being correspondingly more efficient) and reduces the charge in warmer weather.
 

PaulRainbow

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I have a 60w solar panel connected to two 110ah domestic 12v sealed batteries via a photonic 10amp controller. My question relates to the out of the box settings for sealed batteries which are a fair bit higher than my Dometic 20amp charger which is set at 13.8v max and the alternator which charges at 14.4v. The controller settings are as follows. Should i leave well alone or change any of them?

Your mains charger is set too low. It should be 14.4v and 13.6v float. The settings of the solar controller are not something i'd recommend for SLA batteries. Try the following ;

Boost duration 120mins
Equalise duration 0mins
Over volt disconnect 15v
Over volt reconnect 14v
Equalize charging volt 0
Boost charging volt 14.4v
Float charging volt 13.6v
Boost reconnect charge volt 13.2v
Charging limit voltage 15v
 

Ammonite

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Your mains charger is set too low. It should be 14.4v and 13.6v float. The settings of the solar controller are not something i'd recommend for SLA batteries. Try the following ;

Boost duration 120mins
Equalise duration 0mins
Over volt disconnect 15v
Over volt reconnect 14v
Equalize charging volt 0
Boost charging volt 14.4v
Float charging volt 13.6v
Boost reconnect charge volt 13.2v
Charging limit voltage 15v

Thanks Paul. The out of the box settings I quoted are for SLA batteries although that is at 25 degrees C. The engineer i spoke to suggested I switch the default to Gel which are very close to the values you've said, if the boat is sat on the mooring for any length of time. How did you arrive at your values, particularly the float, as most of the chargers ive seen specify 13.8v unless you're reducing it slighty for the UK?
 
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PaulRainbow

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Thanks Paul. The out of the box settings I quoted are for SLA batteries although that is at 25 degrees C. The engineer i spoke to suggested I switch the default to Gel which are very close to the values you've said, if the boat is sat on the mooring for any length of time. How did you arrive at your values, particularly the float, as most of the chargers ive seen specify 13.8v unless you're reducing it slighty for the UK?

13.8v is the upper limit float voltage for SLA batteries, no point setting that when you're using solar panels that are keeping the batteries fully charged for days/weeks on end.

Gel is usually a little higher, so it seems odd that it's closer to my figures, what voltages is the gel setting for that controller ?

It would also concern me greatly if my sealed batteries were being equalised. You can't top them up, so equalising them will no doubt shorten their lives.
 

PaulRainbow

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For SLA there is an equalise phase after the initial boost but its only at 14.6v so not a 15+v equalise that you might do every month or two with unsealed. For Gel its a 14.4v boost with a 13.8v float and no equalise. You can take a look here.
http://www.photonicuniverse.com/upl...xx24B_solar_charge_controller_user_manual.pdf

Thanks. I'd still go for 14.4v and 13.6v, with no equalising. But, if you're seeing 15v at the batteries, something is wrong, faulty controller i imagine.
 

Ammonite

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Thanks. I'd still go for 14.4v and 13.6v, with no equalising. But, if you're seeing 15v at the batteries, something is wrong, faulty controller i imagine.
Im not sure you are right. The temperature compensation coefficient for this controller is 0.003v x the number of degrees below 25 per 2v cell which in my case would be circa 0.36v at 5 degrees which added to the 14.6v equalisation is 14.96v. I think im going to go with the Gel settings to be on the safe side but what the engineer at photonic said explains what ive been seeing so i dont think the controller is faulty. Time will tell :)
 
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