wints Posted May 24, 2015 Share Posted May 24, 2015 A bit of advice sought. My solar regulator has a few parameters that can be set by the user. One of them being the voltage at which the regulator stops charging the leisure batteries. When I first installed the solar reg this cut off voltage was factory set at 13.8 V. I read somewhere that this voltage (13.8) is not sufficient to fully charge the leisure batts in a motorhome, and that it should be upped to about 14.5 V. I thought that a bit high (don't know why) so set it at 14.2 V. My 150 watt solar panel and 2 x 110 amp batteries appear to be performing ok, but does my solar charging regime need tweaking ? all advice welcome thanks Allen Link to comment Share on other sites More sharing options...
Dave C Posted May 25, 2015 Share Posted May 25, 2015 wints - 2015-05-24 11:45 PM A bit of advice sought. My solar regulator has a few parameters that can be set by the user. One of them being the voltage at which the regulator stops charging the leisure batteries. When I first installed the solar reg this cut off voltage was factory set at 13.8 V. I read somewhere that this voltage (13.8) is not sufficient to fully charge the leisure batts in a motorhome, and that it should be upped to about 14.5 V. I thought that a bit high (don't know why) so set it at 14.2 V. My 150 watt solar panel and 2 x 110 amp batteries appear to be performing ok, but does my solar charging regime need tweaking ? all advice welcome thanks Allen Not a simple answer as it depends on the type of battery. Check out what the manufacturers of your battery say. Dave Link to comment Share on other sites More sharing options...
Charles Posted May 25, 2015 Share Posted May 25, 2015 It also depends on temperature, if you're not sure you did the right thing by setting it lower. My solar controller is home made and I set it to 14.4v. Check out Battery University website, it's very informative: http://batteryuniversity.com/learn/article/charging_the_lead_acid_battery Link to comment Share on other sites More sharing options...
lennyhb Posted May 25, 2015 Share Posted May 25, 2015 If it is a multi stage regulator, for wet cell (standard battery) 14.2 is OK max of 14.5v, on a multi stage regulator once the voltage has reached 14.2 it should drop back to 13.6 - 13.8v as a maintenance charge. If you have AGM batteries they need to reach 14.8v for a full charge. If you have Gel batteries 14.2v is OK but unless you have a Gel setting on the charger they will not get a full charge as they need to be held at 14.2v for 8 hours to fully charge. If it is a single stage charger 14.2 will be OK for Gel's & AGM, but may overcharge a standard battery probably better to leave at 13.8, but they will not receive a full charge. Link to comment Share on other sites More sharing options...
Harvey Posted May 25, 2015 Share Posted May 25, 2015 I am not an expert but I have my charge controller manual here. It is a pwm controller. there are setting options for type of battery, those being:- Sealed, Flooded and Gel and then charging specs. are listed respectively for each as follows. Equalizing charge voltage: 14.4V, 14.6V, 14.8V. Boost charging voltage: 14.2V, 14.4V, 14.6V Float charging voltage 13.7V for each. It seems that a 'sealed' battery is just a flooded one that cannot be topped up: that is my understanding anyway. hth Harvey Link to comment Share on other sites More sharing options...
aandncaravan Posted May 25, 2015 Share Posted May 25, 2015 I suspect there is a misunderstanding of the manual, as no Motorhome Solar Regulators we have seen 'stop charging the batteries' at any voltage. What they tend to do is have a voltage at which they 'trickle charge' the battery, often called the Float voltage and usually around 13.8v. Almost all regulators still force fed the battery, albeit at a low rate, even when on Float. None actually stop the charge altogether. If your manual is talking about the Float voltage, this should be at the preset voltage of 13.8v as it will only drop to 13.8v when the regulator thinks the battery is 'fully charged'. Note that this 13.8v is too high for an AGM battery, but then AGM batteries should not be used in the Motorhome habitation area anyway as none of the Charger units currently installed in Motorhomes supports them. Most motorhomes made before 2014 will also not have an appropriate Alternator for AGM batteries. More important is the CURRENT that is passed at the 'Float' voltage, it should be almost nothing,why continue to put ANY charge into a battery that is full? Link to comment Share on other sites More sharing options...
wints Posted May 25, 2015 Author Share Posted May 25, 2015 aandncaravan - 2015-05-25 2:34 PM More important is the CURRENT that is passed at the 'Float' voltage, it should be almost nothing,why continue to put ANY charge into a battery that is full? On the sunny days as the voltage rises the current does reduce, and at 14.2V the current is almost zero. It does appear that the float voltage can be user set on my regulator. If this is the case should I leave it at 14.2V or not ? And then there's the equalisation stage....what voltage and for how long, and how often? regards Allen Link to comment Share on other sites More sharing options...
aandncaravan Posted May 25, 2015 Share Posted May 25, 2015 No 14.2v is too high a Float voltage for almost all batteries. What batteries do you have ? Make, technology and size? Link to comment Share on other sites More sharing options...
wints Posted May 26, 2015 Author Share Posted May 26, 2015 aandncaravan - 2015-05-25 4:12 PM No 14.2v is too high a Float voltage for almost all batteries. What batteries do you have ? Make, technology and size? Thanks to all for the replies. The make is 'Lion', I'm sure they are FLA technology, and they are 110ah...353mm Length, 175mm Width, and 190mm Height. The batteries are less than 1 yr installed, and the green 'magic eye' does glow green. My solar reg, as it's charging, indicates a bulk charge, where the amps is constant, and as the voltage rises it will pulse charge, and the amps vary....then as the voltage gets near my imposed limit of 14.2V the amps drops to maybe 0.1 or 0.2. I have raised this voltage once, to 14.8V for approx 3 hrs, when I was reading about a maintenance / equalisation charge. Hope that makes sense. regards Allen Link to comment Share on other sites More sharing options...
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