Volt Amp Hour

Volt Amp Hour
How long would it take to charge a 212 amp hour 12 volt deep cycle battery using a 60 watt solar panel?

I'm trying to develop a DIY grid tie system & know only the basics about electrical work.
No worries guys I'm a master plumber & have a friend who is a master electrician who would be doing all the wiring. He wasn't around for me to ask initially. Thanks for the answers!

A typical 60W panel has a 4A short circuit current from spec in first link below. This is most likely about 3.5A of peak sun charging current.
Depending where you live, you may get 2 to 5 hours of peak sun charging current a day. You should be able to find this figure on the internet for your area. It is the number of equivalent full sun hours (that the panel will provide 3.5A). It will take all the daylight hours to achieve this equivalent. Lets say you have 3 hours equivalent, so you will get 3.5A x 3h = 10.5Ah per day average.

The battery is 212Ah, so it takes (1.4 x 212 = 300Ah) to charge it. How many days is this? Divide 300Ah by 10.5Ah per day to get 29 days. This assumes no power lost from the battery over that time. Basically the battery (depending on type) could lose almost that much charge over a month from self discharge, so this panel would just keep a battery of this size more or less fully charged if there is no load.

With an MPPT (Maximum Power Point Tracking) controller this figure could be improved, as the charge is derived from the maximum power, not the maximum current, and could provide more current than the maximum from the panel (using internal electronics).

If you want a grid tie system you need a higher voltage to operate the grid tie inverter. You don't need batteries, that is one of the reasons for using such a system. These inverters typically require 150-500V from the panels. This is for good reasons of efficiency and cost. Look up "Sunny Boy" (a German model popular in the US and Australia and Europe at least) to get an idea. This inverter adjusts the load automatically to use the input voltage that gets the maximum power from the panels (MPPT tracking). You need 10 x 12V panels in series to get this voltage. That means you can deliver about 600W to the inverter. Usually smaller systems target 1KW as the power from the panels, using bigger panels, or 24V modules etc. The design starts with the total wattage of the panels, as this is the high cost item. A 1KW system may not export much power at all.

I recommend you research this much further, or get some sort of consultancy with someone familiar with your region before you go ahead. There are plenty of references on the web. The wiring is at voltages similar to household voltages so you should get a suitably qualified electrician to do that work.

I know it seems disappointing, but the power from a solar panel is small compared with household use, especially as the full power only occurs a few hours a day. For example, the standby power from your appliances alone will exceed the 60W rating of the panel, so it makes economic and environmental sense to eliminate that by turning things off at the wall outlet. This panel could perhaps power such a small thing as a network router on a 24 x 7 hour basis.

Depending where you live, solar hot water may make more sense than an electrical system, as it represents more energy saving due to higher efficiency, and also is more practical for a DIY project.

You may get government grants, Renewable Energy Certificates (RECs) etc. to offset the cost of some systems in some regions. Hope this helps.

Greenworks 21602 20-Volt Lithium Ion 12-Inch Cordless Electric String Trimmer/Edger with 6 Amp/Hour

...

...

NP7-12 12 Volt 7 Amp Hour SLA Alarm Battery - 3 Year Free Replacement Warranty Powerstar 7AH Battery
NP7-12 12 Volt 7 Amp Hour SLA Alarm Battery - 3 Year Free Replacement Warranty Powerstar 7AH Battery
$19.55
Today's PowerStar® Series is the culmination of more than a decade of battery manufacturing experience. High energy density, leak proof construction, excellent performance in either float or cyclic applications and long service life combine to make the PowerStar® Series the most reliable and versatile maintenance free rechargeable sealed lead acid batteries available. 3 Year Warranty When Used I...
Powersonic PS-1270F1 - 12 Volt/7 Amp Hour Sealed Lead Acid Battery with 0.187 Fast-on Connector
Powersonic PS-1270F1 - 12 Volt/7 Amp Hour Sealed Lead Acid Battery with 0.187 Fast-on Connector
$14.68
This is a replacement SLA battery for Power Sonic PS-1270-F1 with Terminal F1 (0.187" x 0.032"). We supply only brand new, factory fresh, high quality batteries. We guarantee the best price and 100% compatibility with your Power Sonic PS-1270-F1 model. The replacement sla batteries also include a minimum of one year warranty. Popular applications for our sla batteries are UPS, emergency lighting, ...
12 Volt 7 Amp Hour Sealed Lead Acid Battery (12v7ah , 12v 7ah , 12 V 7 Ah) Replacement
12 Volt 7 Amp Hour Sealed Lead Acid Battery (12v7ah , 12v 7ah , 12 V 7 Ah) Replacement
$10.30
Interstate Batteries Power Patrol Lead Acid Battery, 12V 7Ah (SEC1075) Replacement...
Kawasaki 840045 Black 19.2-Volt 1-1/3-Amp Hour NiCad Pod Style Battery
Kawasaki 840045 Black 19.2-Volt 1-1/3-Amp Hour NiCad Pod Style Battery
$24.99
Kawasaki 840045 Black 19.2V Replacement BatteryReplacement 19.2V BatteryCompatible with all 19.2V Unisource Tools3-5 hr recharge timeClip-on style fits Kawasaki regular duty cordless toolsABS housingNeed more information on this product? Click here to ask....
RIDGID 18-Volt Lithium Ion 4-Amp/Hour Pack R840087 (Retail Package)
RIDGID 18-Volt Lithium Ion 4-Amp/Hour Pack R840087 (Retail Package)
$95.99
RIDGID introduces its new 4.0 Ah Hyper Lithium-Ion Battery. With their new and improved chemistry these 4.0 Ah batteries get up to 4 times the run time of standard lithium-ion batteries. All Hyper Lithium-Ion batteries are built for high performance. They're protected from overheating, overloading and overcharging through their triple protection electronics design. Their chemistry allows for maxim...
6v 4ah Sealed Lead Acid Battery (6v4ah , 6 Volt 4 Amp Hour , 6 V 4 Ah, 6volt 4 Amp Hour) (2)
6v 4ah Sealed Lead Acid Battery (6v4ah , 6 Volt 4 Amp Hour , 6 V 4 Ah, 6volt 4 Amp Hour) (2)
$28.99
This is a direct replacment for 6v 4 amp hour batteries. Spaded terminals on top. Build to last and extra long cycle life....

...

12 Volt 7 Amp Hour Alarm Battery
12 Volt 7 Amp Hour Alarm Battery
$3.70
This is a replacement SLA battery for Universal Power UB1270 (40800) with Terminal F1 (0.187" x 0.032"). We supply only brand new, factory fresh, high quality batteries. We guarantee the best price and 100% compatibility with your Universal Power UB1270 (40800) model. The replacement sla batteries also include a minimum of one year warranty. Popular applications for our sla batteries are UPS, emer...