sears batteries marine
Want to power this with solar panels?
I want to build a standalone wifi repeater — powered by the sun. The problem is how much solar power and how big of a battery?
net draw 4.5v @ 0.66A with load
net draw 4.5v @ 0.60A no load
I’m assuming the best choice would be a 6v battery with a a couple diodes in series to induce ~1.5v drop. Then, I need something to charge it — I found 12v 6w solar chargers in the automotive section of Sears and 16v 2w solar chargers in the marine section of Dick’s Sporting Goods.
How many solar panels and what capacity batteries should I use? Is this the best method or should I use a voltage regulator and go with 12v batteries?
I need this to be as cheap and simple as possible…
I never said anything about using an inverter, changing DC into AC back to DC is just stupid…I’m saying to use a REGULATOR which takes a range of higher voltage, unregulated DC and outputs lower voltage, regulated DC. This is how most car-cellphone chagers work (cellphones use 4-6v to chage)
You will find a much larger selection of system components to make a 12V solar system rather than a 6V solar system. So you might consider finding a switching regulator to drop 12VDC down to 5VDC, then use a diode to further drop it to about 4.4V. A switching regulator can be had with efficiencies in the 85% range. Avoid a linear regulator; its efficiency will be less than 5/12 = 42%.
Assume the following design criteria (adjust to your liking):
1. battery to be a deep-cycle (a.k.a marine battery)
2. battery discharging stops at 20% capacity
3. battery nominal voltage 12Vdc
4. run-time on battery 3 days between charging (due to cloudy days)
5. effective charge time 6hours/day at full output (this depends on your lattitude and season).
6. 12Vdc/5Vdc switching power supply with 85% efficiency
7. Load is a continuous 0.66A at 4.5V
8. Battery charging is 78% efficient
9. Solar panel operates at 17.1V output (maximum power point)
Calculations:
The needed battery capacity (to 20% charge) in ampere-hours is:
0.66A x 24h/day x 3 day x 5V/12V / .85 / .80 = 29.1AH
The number of kWh needed per charge cycle (6 hours) is:
29.1AH x 17.1V / .78 = 638 VAh ==> 0.638kWh
The average current required during the 6-hour charge cycle is:
29.1AH / 6H / .78 = 6.22A
The nominal solar panel size required is:
6.22A x 17.1V = 106W
Most solar panels today are constructed of strings of 36 individual cells. These panels require that a solar charger be used to regulate the charge current (to preclude overcharging the battery). A simpler system is to obtain a solar panel with 33 cells per string. This is considered to be a self-regulating panel that can be connected via a diode to the battery, without a charge controller. It is a less expensive system, but it won’t charge as well as a 36 cell panel will on an overcast day.
As cheap and simple as possible…
Consider relaxing your design criteria. E.g., allow outages after 1 day. Power down the access point at night or during periods that it isn’t used.
Good luck! Sounds fun.
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Black & Decker VEC1093DBD Smart Battery 40/20/10/4 Amp Battery Charger $96.83 When your car battery goes dead, a jump-start is only a quick fix for the problem that may reoccur. The solution is to recharge the battery, using a product like the Black & Decker Smart Battery Charger. Fully Automatic Charging The Smart Battery Charger is fully automatic and electronic, with a Digital Smart microprocessor control and an LED indicator for selecting your charging rate. The three … |
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Glentronics 24EP6 The Basement Watchdog Emergency Sump Pump Standby Battery $84.99 Standby battery delivers 6 continuous hours of power for The Basement Watchdog emergency sump pump. Carton is designed to nest under The Basement Watchdog emergency sump pump. 1 year replacement warranty. (Battery acid not included)…. |
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Schumacher SEM-1562A 1.5 Amp Speed Charge Maintainer $19.00 Float-mode monitoring keeps 6 & 12 volt batteries fully charged; Auto-switch from Full Charge to Float-Mode Monitoring; LEDs indicate: Charging, Charged and Trouble; Quick-Disconnected Harness – Snap connectors in seconds – Use 50-amp clamps or permanently attach to hard to reach areas; Maintain batteries on seasonal equipment; 1.5 amp charger & maintainer; Reverse-polarity protection; Perf… |
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Schumacher SSC-1000A SpeedCharge Battery Charger and Maintainer with 50-Amp Battery Clips $51.79 The Schumacher SSC-1000A Ship ‘N’ Shore SpeedCharge Charger is a versitile, fast and efficient 12-volt battery charger/maintainer suitable for use with a variety of lead-acid battery types used in everything from tractors, motorcycles, jetskiis and snowmobiles, to those found in cars, trucks and SUVs. It features fully automatic microprocessor control; automatic multi-stage charging allowing for … |
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Schumacher SC-1200A SpeedCharge 12/8/2 Amp Charger/Maintainer/Starter/Tester $39.95 12A/8A/2A, Speed Battery Charger, For 12V Batteries, 12A Fast Charge Monitors Battery Condition & Adjusts Charge Rate Downward To Prevent Battery Damage, For Car, Truck Marine, RV, Farm Equipment, Agm, Gel Cell & Deep Cycle Batteries, 8A Medium Self Adjusting Charge Rate Ideal For Everyday Charging Needs & Keeping Your Battery In Peak Condition, 2A Slow Charge For Charging Small Batteries & Mainta… |
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Battery Tender Waterproof Jr. Motorcycle Battery Charger $52.95 12V-800mA charger is 100% waterproof, lightweight and compactThree-step constant current charge program with SuperSmart technologySpark-proofShort circuit and reverse polarity protectedWeighs just 1 lb…. |
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Master Lock 2953AT 12-Volt DC Portable Winch $56.99 No need to buy a winch for each vehicle or trailer, this portable DC-powered unit mounts to any hitch or flat surface to haul in that boat, vehicle, trailer, and more! The winch can be temporary or permanently mounted to either a ball-mount hitch or a flat surface. A parallel-shaft gear ensures efficient power for rolling wheeled trailers and vehicles up to 6,000 pounds, pulling things up to 5,000… |
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Black & Decker VEC1093DBD Smart Battery 40/20/10/4 Amp Battery Charger $96.83 When your car battery goes dead, a jump-start is only a quick fix for the problem that may reoccur. The solution is to recharge the battery, using a product like the Black & Decker Smart Battery Charger. Fully Automatic Charging The Smart Battery Charger is fully automatic and electronic, with a Digital Smart microprocessor control and an LED indicator for selecting your charging rate. The three … |
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Glentronics 24EP6 The Basement Watchdog Emergency Sump Pump Standby Battery $84.99 Standby battery delivers 6 continuous hours of power for The Basement Watchdog emergency sump pump. Carton is designed to nest under The Basement Watchdog emergency sump pump. 1 year replacement warranty. (Battery acid not included)…. |
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Schumacher SEM-1562A 1.5 Amp Speed Charge Maintainer $19.00 Float-mode monitoring keeps 6 & 12 volt batteries fully charged; Auto-switch from Full Charge to Float-Mode Monitoring; LEDs indicate: Charging, Charged and Trouble; Quick-Disconnected Harness – Snap connectors in seconds – Use 50-amp clamps or permanently attach to hard to reach areas; Maintain batteries on seasonal equipment; 1.5 amp charger & maintainer; Reverse-polarity protection; Perf… |
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Battery Tender Waterproof Jr. Motorcycle Battery Charger $52.95 12V-800mA charger is 100% waterproof, lightweight and compactThree-step constant current charge program with SuperSmart technologySpark-proofShort circuit and reverse polarity protectedWeighs just 1 lb…. |
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Schumacher SSC-1000A SpeedCharge Battery Charger and Maintainer with 50-Amp Battery Clips $51.79 The Schumacher SSC-1000A Ship ‘N’ Shore SpeedCharge Charger is a versitile, fast and efficient 12-volt battery charger/maintainer suitable for use with a variety of lead-acid battery types used in everything from tractors, motorcycles, jetskiis and snowmobiles, to those found in cars, trucks and SUVs. It features fully automatic microprocessor control; automatic multi-stage charging allowing for … |
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Schumacher SC-1200A SpeedCharge 12/8/2 Amp Charger/Maintainer/Starter/Tester $39.95 12A/8A/2A, Speed Battery Charger, For 12V Batteries, 12A Fast Charge Monitors Battery Condition & Adjusts Charge Rate Downward To Prevent Battery Damage, For Car, Truck Marine, RV, Farm Equipment, Agm, Gel Cell & Deep Cycle Batteries, 8A Medium Self Adjusting Charge Rate Ideal For Everyday Charging Needs & Keeping Your Battery In Peak Condition, 2A Slow Charge For Charging Small Batteries & Mainta… |
