[10w solar panel charging]

21 hours ago, spirou said:

The only relevant voltage reading you get is under no load/charge e.g. at night with everything turned off. 13V during day time is largely irrelevant, it's what the panel is putting out but not real SOC of the battery.

In any case, even under 2x weekly light use regime, if you're only seeing 13V it's not enough. 13.2V is considered a storage charging voltage, most chargers maintain even higher float charge, around 13.6-8V.

Also, this is in summer. You're not going to see 1W out of that panel during winter. As a reference, a few years ago over xmas in south of Finland, I got a max! of 8W at mid sunny day out of 320W of solar panels on the van.

10W would be OK for some LED lighting etc. in that office but not much more if you want to keep that battery healthy for a while.

Thanks for the helpful info above.

[10w solar panel charging]

7 hours ago, spirou said:

I'm going to guess the combined standby power draw of inverter, printer and anything else is more than that little panel can provide at best of times.

He turns off the inverter and printer to save the battery

[10w solar panel charging]

13 hours ago, MikeF said:

A 10 watt panel won't meet the demand  for small office To charge the battery the solar panel and its controller  needs to charge the battery to over 14 volts. It's just too small. This type of panel will maintain a battery  that's idle,  but won't supply any useful power.

A minimum setup would  be a 100 watt solar panel and controller.

https://www.amazon.co.uk/ECO-WORTHY-Panels-Controller-Off-Grid-Battery/dp/B01N1H66G5/ref=sr_1_7?crid=1G0P7S8COW0PS&keywords=100w+solar+panel+kit&qid=1691108633&sprefix=10+0watt+solar+panel%2Caps%2C202&sr=8-7

Having reread your post you say, '30  minutes per week' , that's not a lot of office time!

Before advising further the knowing the actual hours per day and equipment used, ( a printer won't do anything useful just by itself) would be useful.

Mike

He said he does prints about 30 pages twice a week (60), and despite it only being 10w it seems to top it back up?

[10w solar panel charging]

Hello all, my friend has a small shed he uses as a office in the garden, and wants to charge/top up his battery via his recently bought 10w solar panel, £30 off amazon.

He only draws power from it using a new desktop epson printer and a low powered led lamp around 30 mins per week, via a 600w inverter.

The battery i advised him to buy was a 100ah efb yuasa leisure batt, because i use them for other things and have found them good.

Do you think with his little usage, the small 10w panel will be ok on the batts health over time? The contoller on the panel has overload protection and seems to be ok so far (1week) ? Under load it drops from 13v to 12.6v, then left to solar charge, by the next day or two its around 13v again.

Any advice would be great

Thanks m