I have a 24V 165W BP Solar Panel. I plan on using eight 12V 35 amp hour sealed golf cart batteries in parallel for my battery bank. I plan on purchasing a charge controller and an inverter for my system, but I am not sure which charge controller and inverter to purchase. Will any 12V charge controller work? Do charge controllers take higher voltages, 24V in this case, and step it down for the battery bank? My primary concern is whether 24V is too much voltage to go into a 12V battery bank. If you guys have any suggestions for affordable efficient charge controllers and inverters, please let me know.This system will be used to power a computer 24 hours a day, 7 days a week.
Yes you can but you need to regulate the voltage you can't just straight hook up 24v solar panels to 12v battery banks. You need some way to monitor the battery banks charge so you do not overcharge or charge it up to fast. Most 12v batteries charge via a 14-16v source. upping it to a 24v source would be ok but you should definitely limit the time it is exposed to 24v. The difference in voltage causes the electron flow to the battery to charge it. Increasing the voltage would decrease the charge time but also would generate a lot more heat and amps as well as possible battery damage. You need a battery control station that will take the incoming solar voltage and send it to the battery controller to maintain battery charge. A very pricey add on to your solar panel.
First i cant believe the panel is 24 vbut if it is just hook the positive of one battery to the negative of the other that gives a series produced 24 volts.from the two remaining leads from the batteriesnow getting the 24 volt back to 12 v calculate your maximum wattage and from that use PI x E to get the amperage.find a 120/240 (2:1 ratio transformer) and put the 24 volts in on the primary side and your back to a 12vdc on the secondary .Use this power to operate the inverter to get 120 vac and there ya go the lights are onthe more of the two battery 24 volt systems you parallel the more the amp/out at 12 v and inverter output accordingly can be expected.the trans former can be picked up surplus at lots of wrecking yards where industrial sites dump or military offerings are they can be very cheap in my location i generally buy them for the scrap copper price of 1.35 / poundat 20 to 30 pounds that's cheap.Merry Christmas from the E.PS the inverter size should be chosen car fully as overworking the inverter is is not the problem its wire heat and contact depletion that will cause problems .I have personally used an array of 1.5 v 200a/h wet cells to run a 4000 watt inverter .the solar panel was the most expensive part of the entire systemat 2500.00it was 12 vdc. Merry Christmas from the E.
Most any charge controller will work as long as the input voltage is rated to handle the open circuit voltage of your panel, which may be in the 40V range. The solar panel's voltage will drop to match the load during charging; it just won't be as efficient as it could be unless you get a controller with maximum power point tracking (MPPT). MPPT will get the most power from the panel and convert it to the proper charging voltage for your battery bank.
So your panel supplies 24 Volts 6.875 Amps. Thats the theoretical rating. In reality your panel must be supplying around 28 volts. And eight 12V, 35A batteries would make 24V,140A battery pack. If you have to charge a 24 volt pack you need to supply more than 24 volt in order to overcome EMF resistance. Ideologically you need 10% more power minimum so you have to charge with at least 26 - 28 volts otherwise your batteries won't charge. And charging 140A with 6 A would make the charging time 140/623.333 hours. Thats almost a day. I suggest you use a voltage regulator to keep the voltage more than 26 volts or better would be to step up the voltage to 30 volts then use a voltage reg in case your panel supplies no more than 24 volts. And to decrease the charging time, put more panels in parallel remember that Lead Acid batteries have to be charged only from 6-8 hrs minimum, so that would make a max charging current of 140/817.5 Amps. So don't put more than 3 panels in Parallel or you'll destroy your batteries.
