No. Yep batteries just doubles the capacity. This means you can power your stuff for twice as long. Also means it takes twice as long to charge it all back up again.

www.campingandcaravanningclub.co.uk/helpandadvice/technicalhelp/power/solar-power/ this is a good article.

Overcast no sun= best Pv Cells MT CIS cells. Lets say 160 wp installed....they will charge with 1 amps..so no way! Overcast sunny, 2 Amps also no way.. (asume a standard Rv has about 80 - 100 Ah batt cap..so you need to recharge 5,5 - 9,5 hours with 5- 9 Amps...to get 50 Ah to be efilled! Experience is a 160 Wp Solar ( 2 panels) gives no more than 8 /9 amps permament and at best ( SUNSHINE, SUMMER, 12 o Clock no shade) so summer no Problem, at all, heat reduces efficiency though..winter you need a larger battery and eventually go to the grit for 1 h or 2 after 3 - 4 days or drive and charge ( best with Booster) I do have a Lifephos installed 160 Ah, with B to B, so can discharge more than 80% no damage, voltage stays..solar trickle no issue, power recharge 40 Amps plus Solar..no problem..refill in 1 - 2 h no problem + 60 % less weigth ( I carry 27 kg instead of 72 - removed 2 100 amps Agms.) ideal,would be 2 MT CIS cells ( ideal when overcast and partially shaded) plus 2 x flex 100 Watt, low weigth in series to apply MPPT that covers all! ( including fridge and aircon in summer) love Daves Videos

very helpful article, thanks.

Hi Koudacyen, The Answer to that is a BIG NO! I've just had over a month in Northern France, and a pair of AGM's in my Hymer T failed on the 1st Day. Now, to start with, the deception arose as rdsult of my panel reading voltage between 13.8v & 14. 4v. Didn't have my AMP Meter with me, so struggled to get to the bottom of it. Rang my Motorhome Electrician, away on Hols, so with a list of the symptoms rang the Electroblock Specialists A&N in North Wales, no response, so eMailed them, received confirmation that my batteries were doubtless KAPUT + Possibly damaged Electroblock. The false reading on panel seems to be down to the Solar Panel, So..after some consultation as to the Battery type in situ, 2x "AGM's, Start, Stop" He..."No, No, wrong" Not suitable for Motorhomes" especially with an Schault Electroblock Control System. You need "VARTA LFD90 Pro 90 Ah" or "YUASA L35-100 12v 100Ah" both are Deep Cycle. Did a lot of internet research & came away with a good understanding of the nature of the the VARTA & the YUASA. Managed to run for the month + on 240v connections. Got home, tested the Batteries, 1x read 00.0v & the other 11.4v so yes, both Kaput, opted for the VARTA & fortunately my Electroblock wasn't damaged. So, trust someone like A&N, they are experts, look them up.

I built this setup before and From personal experience, I can tell you the problem is not with the battery bank. it's with your fridge and inverter. If you put an amp meter between the battery and the inverter you will see that it peaks over 10amps when the fridge starts and draws 8 - 10 amps whilst the fridge is running and 1 -2 amps on standby. This will drain your batteries very quickly. If you add more batteries to the bank, the mppt may not be able to handle that capacity. it will also increase your maintainence costs on the batteries particularly if your run your batteries below 12.4volts because that will dramatically reduce the cycle of the batteries. It also adds more weight costing you more in fuel. I realise that cost is an issue but may I suggest spending your money on a new 12v fridge rather then more batteries. With out getting to technical, a 12v fridge will use 50 - 60% less power. Providing it doesn't rain for more then 2 days in a row, I can run indefinitely on 240 watts solar MPPT controller 2 x 105 ah lead acid batteries running a 110lt fridge, lighting, charging for phones ect and a tv/dvd. Your set up would more then do the job if you change the fridge and took the inverter out of the equation. Simply by keeping your batteries above 12.5 volts you can almost double the cycles on your batteries saving your money in the long run...

The voltage tells you.

Maltbrew .....which is a good question since lithium-ion is absolute supreme compared with the other batteries!!

Because for most people they are still horrendously expensive

The video is 4 years old.

We use solar instead of generators 😎