How to calculate your solar power requirements

How much solar power do you need?

 

So you want to set your rig up for Solar but you are not sure what size of set up you need? This blog is designed to give you the tools needed to be able to work out exactly what are you are drawing from your rig's batteries and what type of solar set up you need. Knowledge is key when setting up your rig for solar so the more information you have on each and every one of those home comforts devices you plan to take away with you the better. If anyone has a question pop it in the comment section below. I will try my best to answer everyone.

 

 

How to work out Watts, Amps and Volts

A larger solar panle will collect more energy in less time, but just how big does the solar panel need to be?

The power consumption of appliances is usually given in Watts. To calculate the energy you will use over time, just multiply the power consumption by the hours of use. For example:

10 watt device used over 3 hours equals 10 x 3 = 30 Watt

How to convert Amps to Watts

The energy in Watts is equal to the electric charge in Amps times the voltage in volts:

Watts = Amps × Volts

Example

If your device doesn’t have the Watts labelled on it, then it should at least have the input Volts i.e. 240V and the Amps AC it draws such as 240V – 1.5A. You can then use the equation Watts Volts x Amps so 240v x 1.5amps = 360 Watts.

How to convert Watts to Amps

The electric charge in Amps is equal to the energy in Watts divided by the voltage in volts (V):

Amps = Watts / Volts

Example

Find the electric charge in Amps when the energy consumption is 300 watts and the voltage is 240 volts.

300 Watts / 240 volts = 1.25 Amps

 


Do I need a battery?

Solar panels are commonly used to charge a battery – not to charge a device directly. There are a couple of reasons for having batteries. Solar panels might not generate enough wattage to directly power an appliance, but they can build up a higher wattage via a battery. Secondly a battery can regulate the power going in to the appliance at a constant rate. When solar panels are charging a battery it is usually at a varying rate which could harm an appliance if not regulated.

Battery capacity is measured in Amp Hours (e.g. 120Ah). You need to convert this to Watt Hours by multiplying the Ah figure by the battery voltage (e.g. 12V) – see calculations above.

AH refers to amp hours. This rating is usually found on deep cycle batteries. If a battery is rated at 100 amp hours it should deliver 5 amps of power for 20 hours or 20 amps of power for 5 hours.

When choosing a battery, keep in mind the equipment you will be powering and the time in which they will be running. Theoretically a 100Ah battery can deliver 5 amps over a 20 hour period (and so on). Taking into account the average small campsite - with a small 45W fridge running for 6 hours, 3 hours of 15W lighting and 20W of other electronic equipment - the minimum consumption to be expected is 335W. Take this wattage and divide it by the voltage, 12V, gives 28Ah. With the aim of leaving 50% in the battery brings the requirement to 56 Ah per day. A smarter battery setup would be to use an iTECH120 lithium battery. This new type of battery is a fraction of the weight of old style AGM batteries. AGM batteries usually weigh 35kg but and iTECH120 battery weighs just 13kg. You can also use more of the battery capacity in an iTECH120 - 80% which means its usable Amp Hour rating is similar to a 200 Amp Hour AGM. Read more about the iTECH120 HERE

 

What size solar panel do I need? 

Solar Panels power generation is commonly given in Watts e.g. 120 Watts. To calculate the energy it can supply the battery with, divide the Watts by the Voltage of the Solar Panel.

120 Watts / 18v = 6.6 Amps

Please note that Solar Panels are not 12v, I repeat Solar Panels are not 12v. Any one who works out the Amps of a solar panels using 12v as the voltage calculation does not understand solar or has been misinformed. All solar panel voltages should be marked in the item description of our website or on the unit itself.

Check out the iTechworld Solar Panel range HERE

Inverters

The power inverter converts your storage battery power into the 240 volts AC that runs your appliances. Unless you only run 12 volt DC appliances you will need a power inverter to supply your AC.

There are 2 types of Inverters

Pure sine wave and Modified sine wave.

The Pure Sine Wave matches the power to that of which you get from your Electricity Supplier, its clean and you can run any appliances safely even sensitive equipment.

The Modified sine wave used to be considered a dirty power but some aren't as bad as they used to be, you can use this inverter type for  things that don't have sensitive electronics for example fridges, cookers, pumps, You may have to be careful with some appliances such as laptops and TVs so check first.

Check out the iTechworld range of inverters HERE

Charge Controllers/Regulators

All Solar Panels 30 watts and above need a Solar Charge Controller/Regulator. A Charge Controller/Regulator is necessary to protect the batteries from over charging and supply them with the proper amount of energy to promote long battery life. If the charge isn’t regulated it can have a damaging effect on the battery being charged.

Check out the iTechworld range of Charge Controllers/Regulators HERE

 

 

Article author

Ian

ian@itechworld.com.au

 

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Comments

Patrick Usman#1

Hi, How long will it take 260 watts solar panel to fullly charge a 12volts 200amps battery

Terry #2

Hello
I am setting up a off grid system just to run garden lights
20 watts in total
I have 75 ah battery.
But I think the 40 watt solar panel might be too small what size solar panel would you recommend

Gabriel#3

I have 2x 120 watt solar panels, so how many batteries or size batteries can charge from those solar panels?

Paul otieno oyombe#4

hi,i have asolar panel rated
100watts,,what is its equivalent battery capacity charge controller capacity ?

Stephen#5

Hi Ian

I have 3x 10watt solar panels that im running in series with a 12v 100ah battery for an extra battery in my car to run all the extra phone chargers and a small 6 can fridge from land rover, what would you suggest i change or add?

Manie du Plessis#6

Good day. I have 2 X 60 watt solar panels, a 10 amp Charge controller and a 120Ah deep cycle battery. I want to use to operate my camping fridge which draws 5 Amps on 12 volt power supply. Will the combination I have, be sufficient to charge the battery? Regards.

Tariq#7

Sir
My refrigerator run on 220 volt AC it shows 1.2 Amp while running. How many watts solar panel do i need to run this all the day long?

George#8

Hi Ian,
Please let me say that you have a great and informative website indeed. I have been searching for some answers to my solar power requirement and so far I have not come across more detailed information than what I find here.

I am after some clarifications here. I am trying to connect some devices (total watts approx 1000 watts) to a 1000 watts inverter which is connected to a 200AH battery. I am using a 200 Watts rated solar panel to charge my battery.

1. How long will it take to fully charge my battery (say in a clear sky)?
2. How long will it take to fully deplete the 200AH battery when all the devices are connected at once through the inverter and the total power required is approx 1000 watts?

3. My laptop is rated 240 Volts AC, 1.5 Amps, does that mean it requires 360 Watts per HOUR or is it 360 Watts continuous power? I am thinking if its continuous power then my battery will be depleted within less than a hour.
4. What is the best voltage regular to be used here to control the charging of the battery?

Thanks and merry Christmas from Papua New Guinea

George

John Tracey#9

Hi i have 2x 260 watt 15 amp solar panels.
70mppt solar controller
2x 12v 74 ah batterie
Inverter modified sine wave 1500-3000
Wanting to run freezer on my boat
Energy consumption is
0.701 kw h/24 will this run okay or would i need bigger gel batteries

John Tracey#10

Hi i have 2x 260 watt 15 amp solar panels.
70mppt solar controller
2x 12v 74 ah batterie
Inverter modified sine wave 1500-3000
Wanting to run freezer on my boat
Energy consumption is
0.701 kw h/24 will this run okay or would i need bigger gel batteries

MAMOUDOU #11

Hi
I have 6 panels 310 w 24 v
1 inverter 10.000 watts with 5000 running power
1 regutor mppt 60 amp
Batteries 200 ah 12 v ( 5)
What can I run with it

MAMOUDOU #12

Hi
I have 6 panels 310 w 24 v
1 inverter 10.000 watts with 5000 running power
1 regutor mppt 60 amp
Batteries 200 ah 12 v ( 5)
What can I run with it

Linda davis#13

We have a 4 x deep cycle battery setup. How big of a solar panel do we need to keep these charged? We would also like to run a tv, computer and basics.

Radomir Milenkovic#14

I have 60L Companion Fridge/Freezer 80W[12V/4.5A and 110Watt Max@18.00V Solar panel can you please tell me what size Regulator and Battery do I need.
Kind Regards Rad

Brent Pennington#15

Hi Ian,
I just installed a solar kit on my enclosed work trailer. I have a 100 watt solar panel, to a 30 amp charge controller, to a 35 amp hour battery, to a 750/1500 watt inverter. Trying to run a lamp with led bulb, 2 battery chargers for power tools, and a 250 watt desk heater. Everything is fine until I turn on the heater, the fan on the inverter instantly kicks on, and after a few minutes it starts making a high pitch tone, warning me I guess, and I shut it down immediately. What am I lacking? What do I need to do if in the future I want to run more?

Ben#16

Hi Ian, I currently run 2 × 45lt engel fridges through an arkpak battery box with a 130ah battery, with a 160w solar panel, with overcast 38 degree days i found it wasnt enough to last more than 3 days but lasted my camping trip of 5 days during cooler weather over easter,i know the fridges would be working harder during the warm weather but would you recommend a larger say 300w solar panel?? or even 2 solar panels? any help would be much appreciated.

Barry#17

Hi,
I have a large houseboat running on 1000 watts of solar panels for all 12 volt and 240 volt systems. Up front I have an anchor winch which is 24 volts, two 100 a.h. Batteries in series. I normally charge these back at marina from shore power disconnection the seriesl before charging with a 12 v smart charger.I have a spare small 20 watt 17.7v solar panel with a PWM 10 amp controller. Even though the panel is only 17.7 volts, will it charge the batteries left in series ie. 24 volts.
I realise it would take a long time but that is no problem as the boat would normally be left for a week or two between uses.
Thanks,
Barry

Zee#18

Hi, i would like to ask if it is possible that you can use batteries even when grid tied system is installed?or when using off-grid system,you can tap on the grid when there is no enough supply from the battery.

Melinda#19

Hi we are wanting to purchase solar panels for our house boat to run the refrigerator tv and lights but not sure where to even start

Steve Whisner#20

I have a a 5th wheel with 2 deep cell batteries what watt solar panel(s) would I need to keep the batteries charged. Lights, refrig and water pump only, no microwave.
Thanks Steve

Ronald Pietrafeso#21

Good morning, I’m trying to keep a water source from freezing for cattle consumption using a 120 volt 1500 amp heat source. What would I need to achieve this in the way of solar. Thanks in advance

Michelle#22

Hi i am in the early stages of looking at an ‘off the grid’ set up for a 6mx3m portable building as an art studio… it want to operate a small fridge, kettle, lights and an aircon as well
As 2-4 household power points for things like charging mobile phone, computer, printer operations… i would assume that I would need a solar storage battery ….. I assume that it would be a similar set up to an off-road caravan setup .. is there someone I can talk to please to discuss? We live in sunny North Queensland where it does not rain a lot… thanks Michelle

Matthew Henderson#23

hi,
I am planning on running a 318L 240v fridge in a boat. i have 12 × 100ah batteries in my 12v system. I have an inverter that will power the 240v fridge, coffee machine and vacuume every now and then. i am trying to work out what i need to buy from you and in what quantities. When the boat is un attended at the mooring the fridge will be off, but when we are using the boat the fridge will be on 24hrs.

Daniel #24

Hi I have a kids 12v 15a running a 12v25ah lead battery what size solar panel will I need to use?
Thank you

zimiso#25

hi Ian, i have an MV600 -AS ICE Machine, 10amps, start amps 31 and 1600watts. May you please advice on the size of solar modules, number of batteries and size and the inverter size.
Regards Zimiso

Sam#26

Hi there, looking at using a solar with controller and battery just for 12v devices. I know how to hook this up but just wondered what wattage solar panel your would recomend and what amp hour battery. To charge a phone a couple of times, 3 × led lighting at 9watts each and a mini 12v fridge (upto 15tr)
Thanks alot.

Reny#27

Hi ian, i have a 300w solar panel, 30amp PWM controller, 2 units 55Ah each battery, I have a load 70watts waterpump and 2 18watts waterpump of my ponds..i have observed that my battery cannot sustain overnight..what is your advise because i want to load more like my 60watts tv,internet and cable modem

Reny#28

Hi ian, i have a 300w solar panel, 30amp PWM controller, 2 units 55Ah each battery,1000watts pure sinewave inverter, I have a load 70watts waterpump and 2 18watts waterpump of my ponds..i have observed that my battery cannot sustain overnight..what is your advise because i want to load more like my 60watts tv,internet and cable modem

Rajeev Kumar#29

I need to run air pump of 550 W for 24 X 7 for fisheries. Please help me to get the right quantity of solar panel and battery.

Rajeev Kumar#30

I need to run air pump of 550 W for 24 X 7 for fisheries. Please help me to get the right quantity of solar panel and battery.

Matt#31

What kind of setup would I need to run a 800w 1hp pool pump?

Enock#32

Hi Ian Can a 265watts solar panel work with 12v/100Ah and 30A charge controller?

Manytai Gatluak#33

hi Ian. I have 100ah battery new. I want to charge it first and I have two solar with different watts 150 and 130. how many hours to complete for charging.

Terry#34

Ian
I have 130 ah AGM battery in a pop top caravan I would like to run two Engel fridges both 40lt plus 12 volt lights x 3 at night what size solar panel would you recommend to run this setup

Loraine#35

Hi,
I have a 4 berth caravan in storage over the winter and I have a 40w solar panel, would I be able to power my heating.

Regards
Loraine

Robert Scholtes#36

what size solor panel do i need to charge a 12 volt deep cycle battery that I would use on my 12 volt lighting?

Avanthi Modugapalli#37

Hii
Can i know the size of solar panel required to charge 12volts 2amps battery??

Chris#38

I have a 200w solar panel & a 130 ah deep cycle battery. What solar controller & battery cable size do I need. Thanks

Max bunting#39

Hi ian i have 2×100 ah agm batteries in camper we run a 95 ltre waeco dual zone we seem to struggle even with solar panel we where supplied being 120 watts what can you recommend as far solar size pwm / mppt / or dcdc thanks would be appreciated thanks

Kathlea#40

Greetings!

I would like to ask the formula to compute if how many hours do the battery will full charge if I have 250watts of solar panel and a 12v 90AH hours Battery.? Thank you

Andrew#41

I have 2.5kva Luminous Cruze inverter with 220ah x4 batteries and 8 solar pan but the inverter could not carry the four batteries so i remove one battery before it could work perfectly well but still can not pump water, please how many solar pan and inverter kva do i need to power more batteries so i could pump water and still have more energy time? please the house i live is a family house and is a very big upstairs into two places, thanks.

Sheri Corrie#42

I have to live off grid in my 24ft Motorhome this winter. What do I need to charge my 12v battery ?

Fraser#43

Hi, am finding this is still a little above my head, . I have solar system set up which works for lights and temporary usage of invertor but want to set up a system that can run a 60watt appliance constantly, which would probably have to be run via an inverter, was thinking this may be smaller system than my current set up but it looks like I am wrong, is it possible to give me any further advice? Many thanks

Scott E. Crews#44

What do i need to run a 30 amp RV, the fridge, tv, toaster, coffee pot, and 3 led lights are 110 volts

Fraser#45

Hi, am finding this is still a little above my head, . I have solar system set up which works for lights and temporary usage of invertor but want to set up a system that can run a 60watt appliance constantly, which would probably have to be run via an inverter, was thinking this may be smaller system than my current set up but it looks like I am wrong, is it possible to give me any further advice? Many thanks

arihant#46

Hi,
I need to connect a solar panel to my canter, I am installing a deep cycle battery and 24v to 12v converter. Could you plz tell what details you need so you could tell me how many watts solar panels can be fitted.

Scot#47

I had my 100w solar blanket fitted with Anderson plugs , and bought a regulator to suit from a battery place I told him I have a agm 100amph , but the manual on the regulator says wet cell battery only and it is a 10amp solar regulator, would it still charge my agm dry cell glass Matt battery ??

Eugene#48

Hi my house runs from 3phase power.All my electrical components is 220 volt.The amps measured on each phase is 30 amps.What size solar system would you suggest i use.Regards Eugene

Muhammad-Nur A Ishaq#49

Thank you itech world
please I needed help I want to power a 150w freezer with an inverter how do I know the number of panels,size of charge controller and battery size.

John#50

I have 10kva inverter off grid and 100ah battery (20) pic.how wats of sola panels do I need

Dirk Stander#51

Hi there

I have a 1000w 12V inverter with 2x 110ah deep cycle gel batteries. Will 1x 200w 12V solar panel be enough to keep it charged?

Darren Bester#52

Dude, You are super helpful, do you export to South Africa?
- Darren

alan porter#53

hi can I link up solar panels with different outputs to the same regulator,ie 2×100w,1×200w,or are they better all the same output,thanks.

Firdaus#54

Hai alan.. Can you teach me.. How many panel/watt can be use for 30amp regulator.. If u have any formula. Bring it to me.. Thank

Gerhard Willemse#55

Evening Ian, I am in South Africa. Due to power cuts I need to install a second borehole as a backup system, I already bought a 0.375 Kw submersible pump and a 0.37 Booster pump. The submersible is hanging at 30 meters and 14 meters below the water surface. I need to pump the water for 50 meters to a water tank of which the inlet is 2 meters high. I pump water between 15 and 25 minutes per day with the submersible and the Booster is used when we need water in the house. Can you please assist with the requirements pertaining to Solar Panels, Inverter, Regulator and how many batteries of about 120 Ah I must obtain to get the system working smoothly. Regards, Gerhard

Timothy#56

I looking to trickle charge a dual lead/acid battery setup on my boat – wet slip has no shore power.
Dual 12V @ 75 MCA

Thank you very much….

Faisal#57

I have 2 batteries one is 180 ah and second is 100ah can I charge and use them on solar in parallel way..

Troy#58

Hello I have a camper trailer with 3×100amp batteries just wondering what size solar panels would be enough for these batteries. We run an 80 litre Waeco. Thanks Troy

Geoff #59

Hi I’m a carpenter looking to set up my work trailer with solar power to run my power tools. I don’t know where to start and exactly how much output I need, any suggestions? Thanks.

ian#60

i have a 6000w solar inverter a 30a contro;er a 140w fridge and 2x ii50 k batt what size solar pannel do i need

Prince#61

Dave

I have two issues Dave, first i want to run a 1HP electrical submersible pump (48metres) on solar how (300W panels do i need). Seondly do i need a battery and inverter or not?. What size of charge controller do i need.

Thanks

Chris#62

Thank you for the article. I’m busy renovating a retro van and considering how to power it. I love the idea of using solar, but (forgive the potentially silly question) does that mean we have to park our van in the sun? what if we park under a tree where it’s cooler, or on cloudy days etc. We only need 2-3 days off-grid power typically. I’m wondering would it be better to charge battery from the alternator or plug-in and forgo solar?

Trai #63

Hi I’m trying to work out the figures to assist in running a 380w refrigerated vending
Off solar that’ll be running for a total of 12 hrs or possibly 24 hrs.

How big of a panel would I need , battery, regulator and anything else.
And how much could you do it for .
Kind regards Trai.

Miriam#64

Hi Ian,
I have a 600w sinewave inverter and a 80w solar panel. What size battery and a regulator can i use if i have to charger laptop and a at least 5 iphones.

Thanking you in advanve

Miriam#65

Hi Ian,
I have a 600w sinewave inverter and a 80w solar panel. What size battery and a regulator can i use if i have to charger laptop and a at least 5 iphones.

Thanking you in advanve

Miriam#66

Hi Ian,
I have a 600w sinewave inverter and a 80w solar panel. What size battery and a regulator can i use if i have to charger laptop and a at least 5 iphones.

Thanking you in advanve

Memon#67

Hello

would you guide me how much solar power required to 1500Watts load and charge 2×210 Amp batteries.

Rakutuka Kaurimuye#68

Great day,

I hereby would like to query about Solar power required to power our newly erected Warehouse approximately 70 square meters in size. The load will be a hot plate, a couple of freezers, TV, stereo player, computers, printers,cameras etc…

Rakutuka Kaurimuye#69

Great day,

I hereby would like to query about Solar power equipment required to power our newly erected Warehouse of approximately 70 square meters in size. The load will be a hot plate, a couple of freezers, TV, stereo player, computers, printers,cameras etc…

Francis#70

Please help me.How can I know the total wattage of home apliances to be powered by a given solar pannel with its wattage.

Jeff Barnes#71

Ian I have a motor home with a factory 60w solar unit on roof I was thinking of buying a 160w portable system to put outside in sun when home is parked under trees.
My factory ZAMP SOLAR CHARGER #ZS-30AP is it capable of the extra power input ? also is possible to add another solar panel on the roof in conjunction with what I have or better to replace with larger unit

Anger management #72

Have 2 12v 100ah Ahmed batteries and 4- 100w x 6.5a panels with a 30a MPPT controller.
How long should it take to recharge the batteries and will this system benefit from adding 2 more of the same batteries? Thanks

James Henderson#73

hello Ian,

upgrading from 4×80watt panels, 25amp charge controller and 225ah 12v battery bank.

got an 80amp charge controller, now ready for panels.

how does that 80amp limit on the charge controller affect the maximum solar panel array size for a 12v, or 24v battery bank?

M Naveed alam#74

I have 300 watts solar panel can I connect this panel ups battery through the charge controller,how many times require for 2+100ah battery charge

Derek Skilton#75

Hi Ian, I am setting up a solar system to charge the 24 volt cranking batteries on my motor home while is parked up & not being used. I have a 12/24 volt charge controller, but am not sure what size/specification solar panel is required.
Hope you can help.
Regards,
Derek Skilton

Sunday Busayo#76

Good day,

Please I have four solar panel 150watt each and two 200amp battery.
From the display on the controller at peak I see 4.2a from the panel. Will the supply be sufficient to charge the batteries or there is lots of lost from what is expected from the panels.

Also note that I am having 24v from the solar panel

Thank you

Mosaddek#77

Good Post. Thanks for Sharing
I just published some stuff here
https://www.solarpanel.wiki/best-solar-panel-battery-charger/

You may Like
Thanks
Cheers…

HarryNAJ#78

What is the exact size of panel, inverter, battery and controller or regulator do I need to power a two horsepower submisable water pulm

HarryNAJ#79

What is the exact size of panel, inverter, battery and controller or regulator do I need to power a two horsepower submisable water pulm

Al#80

re: : 6volt 5amp sealed battery

What size solar panel would i need , to keep this charged on broken solar fence energiser.

Fitted via the 6volt 240 charger slot
Many Thanks
Al

Lew Shaw#81

Just about to buy a new AGM battery for our caravan.Currently 100ah but thinking 150ah with winter/southern sun angle in mind.How much solar panel wattage do you think prudent please?

Jaco Grobler #82

Hallo Ian
How long will it take aFLEXI?BAJA 105W solar panel to load a 105 AH battery from half full to full. Your site is very user friendly and informative. Thank you.

eddie noonan#83

Hi Ian
I have 4 × 100watt solar panel on my rv
I think its reading 70 volts 5,71 amps
what size mppt controller would I need
I had a cheap 40amp controller just installed and it started smoking , it said 40 amp on the box anyway
kind regards
eddie

jamol regis#84

hello i have 7 300 watts panels what size controller do i need for this set up???/ at the back of the solar panel im seeing vmp 32.6v imp 9.19a imp 9.19a voc 39.8v and isc 9.77a

James#85

Please help me with this.
1. What is the average solar energy required to power 60watts TV, 12v decoder, and 2 standing fans (15v each)

2. What is the watt solar panel and battery that will power 1000watts inveter powering the aforementioned appliances for at least 12 hours.

Cleveland Netherland#86

Ian,

Please write more and more. This the most straight forward solar information that aI have found. For a relative newbie this is like gold.

David#87

Hi,
If I have 2 × 100w panels linked, each with 5.46 AH max output what would be the max output in perfect conditions ie: high UV.
Currently cant get much over 5.46 amps.

tomanddawneBowman#88

I have just bought a pop top with a new I panel solar fitted could I please ask what wattage it is the sixe is 680mm wide x1368mm long it has some numbers I found underneath LA 8HO 860 thankyou kindly

Daniel#89

Hey mate
I have 2x 120 amp battery’s in parallel and was lucky to be given a 125w solar mat, it has a 12amp solar charge controller with it, Is that ok to charge those 2 batteries or does it need a larger amp controller
Thanks

Randy#90

Are there options besides AGM, like Lithium-Ion, that would produce comparable results with less weight? Application is a boat trolling motor array.

Mandy#91

Hi I need your help. I have a solar panel which is 250 watts at 18 volts. That is controlled by a 30 amp Mttp epever unit that feeds 4 X 130Ah deep cycle batteries that are connected on parallel. I also have my batteries connected to my van with a split charge relay. My main power draw is my Mobicool coolbox which draws approx 4 amps per hour. The problem I am having is that the batteries do not seem to last very long. Living in the UK sun can be a premium but during really sunny days the solar panel gets the batteries up to 14 volts. The moment the batteries have to supply the load that’s when the level starts to drop. I am new to all this and wonder if I am doing anything wrong. Great site by the way and so nice to find lots of info in one place

Garba #92

Hi, please guide me I have 10 130 panels with rating 7.1a, which is to have 71a totally but 20a is coming what is wrong

Raul#93

Hi Ian I have 40A DC loads. What size of panels, battery and controller do i take

shank#94

Simple and clear…. Beautifully exaplained… Thanks.

shankar#95

When the battery is too low, the solar panel does not charges the battery…What is the recommended ampere for charging a 120ah battery or the solar panel watt required for charging a 120 ah battery.

Randy#96

Trying to figure out this situation:
Chest freezer draws 5 amps at 115 volts.
I have a 140 watt solar panel, charge regulator and a 2000 watt invertor.
I have 2 deep cycle batteries.
Will this setup work to run my freezer 24/7?

b trust klt#97

what battery can be use for 80wtt panel.thanks I love that help.forums

Johan Sjostrand#98

I need to feed a system that is on 8 amp consumption. I want a batt pack as small as possible. need to feed the consumption as well as charge the batt pack with solar panels (limited space, must be optimized).
any suggestions? it has to run 24/7….

Thanks in advance
//Johan

Johan Sjostrand#99

Sorry forget to tell its a 12v system…

Thanks for you work.

//Johan

Jeff morton#100

Hi Ian , I was wondering how much solar I would need to keep 2 of your 120 ah lithium batteries charged mainly running a 95 waeco cfx fridge and a couple of led lights at night

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