Battery question - solar charger
-
- Engineer
- Posts: 143
- Joined: Mon Jul 09, 2012 5:16 am
- Sailboat: MacGregor 26X
- Location: Haymarket VA
Battery question - solar charger
I have a couple of solar panels set up on my by previous owner but only a single battery. I want to get a second battery and set it up as a house battery and use original for engine only. My question is this .... Can I set up the solar panels to charge both batteries at the same time ? If so how do I do this?
Tere is a controller that works with the solar panels as well.
Tere is a controller that works with the solar panels as well.
- Divecoz
- Admiral
- Posts: 3803
- Joined: Sat Oct 16, 2004 2:54 pm
- Sailboat: MacGregor 26M
- Location: PORT CHARLOTTE FLORIDA 05 M Mercury 50 H.P. Big Foot Bill at Boats 4 Sail is my Hero
Re: Battery question - solar charger
WE can guess and assume but it would be helpful to know what you have.. wattage of collectors, brand and model of controller etc etc ..BTW you really do want batteries of the same age size type and even manufacturer .. do you as well have a battery combiner?
rszobel wrote:I have a couple of solar panels set up on my by previous owner but only a single battery. I want to get a second battery and set it up as a house battery and use original for engine only. My question is this .... Can I set up the solar panels to charge both batteries at the same time ? If so how do I do this?
There is a controller that works with the solar panels as well.
-
- Site Admin
- Posts: 1672
- Joined: Tue Jan 06, 2004 10:50 am
- Sailboat: Other
- Location: Boston, MA
- Contact:
Re: Battery question - solar charger
voltage sensing relay? once the first battery is charged, it will automatically combine the 2 and charge the second. Once the charging goes away, the batteries separate.rszobel wrote:I have a couple of solar panels set up on my by previous owner but only a single battery. I want to get a second battery and set it up as a house battery and use original for engine only. My question is this .... Can I set up the solar panels to charge both batteries at the same time ? If so how do I do this?
Tere is a controller that works with the solar panels as well.
There may be other ways to do it, but this is simple and effective.
That is how I do it on my mac. I charge (via engine, or battery charger) starting battery only, then once the voltage gets up there.. it will combine them, then they separate once the charging is taken away. I can't imagine the charging source matters - engine, charger, solar, etc.
- Russ
- Admiral
- Posts: 7543
- Joined: Thu Oct 11, 2007 12:01 pm
- Sailboat: MacGregor 26M
- Location: Bozeman, Montana "Luna Azul" 2008 M 70hp Suzi
Re: Battery question - solar charger
What Paul said. That's exactly how mine is setup. My combiner will combine both when either batt is being charged. My solar panel is connected to house and will charge both when charging. Motor is on its own batt and will charge via combiner the house batt. Both are separate and isolated when not being chaged.
- Rick Westlake
- Captain
- Posts: 778
- Joined: Wed Aug 22, 2007 4:05 pm
- Sailboat: MacGregor 26X
- Location: Casa Rio Marina, Mayo, MD; MacGregor 26X, "Bossa Nova" - Bristol 29.9 "Halcyon"
- Contact:
Re: Battery question - solar charger
I set my solar-charging system up with a dual-output charging controller, a Chinese knock-off of the Morningstar SunSaver Duo.
(I put the Morningstar SunSaver Duo on my trade-up boat, my Bristol 29.9 - the one I found included a battery meter. Worth considering.)
(I put the Morningstar SunSaver Duo on my trade-up boat, my Bristol 29.9 - the one I found included a battery meter. Worth considering.)
- Bobglas
- First Officer
- Posts: 204
- Joined: Sat May 12, 2012 1:00 pm
- Sailboat: MacGregor 26M
- Location: Jefferson, NY
Re: Battery question - solar charger
Two batteries Perko switch, controller hooked up to the switch, I charge house, or starter or both by using the Perko switch.
- Sea Wind
- First Officer
- Posts: 402
- Joined: Mon Mar 28, 2011 9:45 am
- Sailboat: MacGregor 26X
- Location: Mayo, MD Suzuki DF90hp
Re: Battery question - solar charger
I have the same setupTwo batteries Perko switch, controller hooked up to the switch, I charge house, or starter or both by using the Perko switch.
Re: Battery question - solar charger
You need to consider a number of things....firstly charging 2 or more batteries off one source is not a long term solution ie unless all batteries are exactly the same the controller will "see" an average of the combined voltage ie 12.4 + 12.7=12.5 so will charge as though both batteries are 12.5....probably over charging one and undercharging the other. A voltage sensitive relay will do the same...as the relay opens the combined voltage is what the controller or the motor regulator will see and adjust accordingly.... BUT will guard against a flat starting battery. All of this is further complicated by if the second battery is a different construction ie to make it deep cycle....AGM or Gel....which if charged like a wet lead cell battery will certainly shorten the life of those batteries.....they don't like the higher voltages and should not be "gassed". One solution we have is to have all charging into start battery (and controller set for that battery type)....and then a voltage sensitive relay into a DC-DC charger (set for the house battery type)have a couple of solar panels set up on my by previous owner but only a single battery. I want to get a second battery and set it up as a house battery and use original for engine only. My question is this .... Can I set up the solar panels to charge both batteries at the same time ? If so how do I do this?
Complicated but new batteries are also expensive. We learnt from service vehicles we run....24v but 2 x 12v batteries....we were forever replacing batteries until we realised the use of one battery for 12V loads was causing that battery to be undercharged and the other to cook ie overcharge.
I guess our 2 x 184Ah Geltech batteries at 700-800$ each is another reason to be carefull...in both our camper and Mac we have volt meters and temperature gauges near the biggest load ie refrigeration......the 2 meters combined give us a good idea whats going on....have taught my wife to be aware of temp rising and/or voltage lowering....most of our other loads on board are either intermittent or small so don't really pose a load problem
-
- Admiral
- Posts: 1702
- Joined: Thu Aug 10, 2006 5:08 am
- Location: Berrigan, Riverina Australia boatless at present
Re: Battery question - solar charger
Very good summation Bartmac, mind you I just have all batteries hooked together with the option of using the perko switch and it works ok with the original start battery still going strong after 7-8 yrs despite being flattened several times but they are all the same type.
Re: Battery question - solar charger
A manual switch will only work if the construction/chemistry of the batteries in question are the same...the controller will see the switched on battery and charge it accordingly.............old-timers disease however has set in and I'm looking to idiot proof all systems...This weekend I actually replaced our manual truck switch with a voltage sensitive one which controls our truck to camper and truck to Mac 12v DC-DC charging circuit........even though we have a large voltmeter which lights up when circuit is ON....it has been forgotten ......no damage as our camper or Mac voltmeter would be alerting us...ie higher than expected voltage especially at night....no solar input and thus would expect voltages in the 12.4-12.7 range...with charger going its going to be 13.6-13.8V
-
- Site Admin
- Posts: 1672
- Joined: Tue Jan 06, 2004 10:50 am
- Sailboat: Other
- Location: Boston, MA
- Contact:
Re: Battery question - solar charger
if the batteries are the same use a VSR
if the batteries are different - a voltage follower like Balmar duo charge is a great solution - charge the large house battery and trickle charge the smaller starting battery.
have a manual switch on our big boat... hate it.. way too many times not switching it to charge the proper battery. the duo charge takes the human factor out of the situation.
I prefer the 3 switch + VSR for the mac (2 same batteries).
both solutions takes the human factor out of the situation.
if the batteries are different - a voltage follower like Balmar duo charge is a great solution - charge the large house battery and trickle charge the smaller starting battery.
have a manual switch on our big boat... hate it.. way too many times not switching it to charge the proper battery. the duo charge takes the human factor out of the situation.
I prefer the 3 switch + VSR for the mac (2 same batteries).
both solutions takes the human factor out of the situation.
Re: Battery question - solar charger
One of the problems with battery systems is that most people rely on voltage as some sort of measure as to how well their system is performing......no good...voltage is NOT the measure...amperage is the usage measurement or more correctly Amp hours.....We live in an area where there's a "hippie" element...living on low voltage,solar etc etc...the majority are kidding themselves as to how good their 12v systems are and when the sun doesn't shine it fairly quickly shows the use of automotive batteries in a house system just doesn't work properly....Macs are not a house but if you want a reliable system which will work for more than a weekend it will need $$$ and time or you need to get rid of the load sapping things on your Mac....ie the fridge...most other stuff will be fine
- Sea Wind
- First Officer
- Posts: 402
- Joined: Mon Mar 28, 2011 9:45 am
- Sailboat: MacGregor 26X
- Location: Mayo, MD Suzuki DF90hp
Re: Battery question - solar charger
Isn't this only true if using a combiner or charging in "both"? Even if you have different batteries and you only choose 1 or 2 on a manual switch then the controller would know what to do, right?You need to consider a number of things....firstly charging 2 or more batteries off one source is not a long term solution ie unless all batteries are exactly the same the controller will "see" an average of the combined voltage ie 12.4 + 12.7=12.5 so will charge as though both batteries are 12.5....probably over charging one and undercharging the other. A voltage sensitive relay will do the same...as the relay opens the combined voltage is what the controller or the motor regulator will see and adjust accordingly.... BUT will guard against a flat starting battery. All of this is further complicated by if the second battery is a different construction ie to make it deep cycle....AGM or Gel....which if charged like a wet lead cell battery will certainly shorten the life of those batteries.....they don't like the higher voltages and should not be "gassed". One solution we have is to have all charging into start battery (and controller set for that battery type)....and then a voltage sensitive relay into a DC-DC charger (set for the house battery type)
Complicated but new batteries are also expensive. We learnt from service vehicles we run....24v but 2 x 12v batteries....we were forever replacing batteries until we realised the use of one battery for 12V loads was causing that battery to be undercharged and the other to cook ie overcharge.
I guess our 2 x 184Ah Geltech batteries at 700-800$ each is another reason to be carefull...in both our camper and Mac we have volt meters and temperature gauges near the biggest load ie refrigeration......the 2 meters combined give us a good idea whats going on....have taught my wife to be aware of temp rising and/or voltage lowering....most of our other loads on board are either intermittent or small so don't really pose a load problem
Re: Battery question - solar charger
The controller I have is programmable for battery type...ie bulk , absorption, and float voltages...that only works if all batteries you charge are of that type...start mixing types and you need something more sophisticated
- Obelix
- Captain
- Posts: 523
- Joined: Wed Feb 13, 2008 12:20 pm
- Sailboat: MacGregor 26M
- Location: Port Richey, FL, 26M 2008 "New Love" - 60hp E-Tec
Re: Battery question - solar charger
If two batteries are connected directly in parallel, they would not have dissimilar voltages and the charger would therefor act as if there is only one battery. I somehow don't see how there could be an averaging of voltages by the charger.You need to consider a number of things....firstly charging 2 or more batteries off one source is not a long term solution ie unless all batteries are exactly the same the controller will "see" an average of the combined voltage ie 12.4 + 12.7=12.5 so will charge as though both batteries are 12.5....probably over charging one and undercharging the other.
Obelix