Hi I'm just wondering.
I have a 165 watt solar panel mounted on the roof of my van and I have a 130ah battery. Would I be able to run a 12 volt mini fridge, t.v and lights without any problems most of the time or would I need to turn it all off sometime to let the battery charge?
Unless your running a compressor fridge I would not bother, if your battery is SLA you only have 65ah usable capacity, if that is the case I would consider moving to LiFeP04 say 100ah which provides a full 100ah, not to mention all the other gains with LiFeP04 over SLA, decent 100ah LiFeP04 leisure batteries can be had for around £200 these days, not the £1000 that they once were say 5 years back.
Also the drain from a mini fridge if of the Thermoelectric type, will further reduce the capacity available from a SLA battery, which will suffer from the effects Peukerts law, unlike LiFeP04 which is not really subject to Peukerts law.
The mini fridge will have a power rating - perhaps 60W or so (5A at 12V). That's a level of drain that will likely be more than a 165W solar panel can keep up with over a 24 hour period. 165W is peak output in ideal conditions. The controller may have between 5% and 20% loss. If you assume you can achieve an average of 60W through the daylight hours, then there is nothing left to top up the battery. If daylight is 12h you need 12h of battery running - 60ah - to run the fridge over night.
So - your battery (from 100% full to 100% empty) would support 2.5 nights, but that would probably kill the battery. 100% drain on a lead acid battery is not recommended. If it's LiFePO4 (Lithium) then you can drain it without damaging it.
Net net - for a weekend (2 nights) this would probably be ok. For a longer period, it will be very much dependent on sunny weather and optimum solar panel position.