my LED installation

I converted over to LED bulbs in my former Silver Shadow but many of the lights were already LED from the factory.  If you have the older style receptacle shown below you can easily convert to LED style bulbs.  I don't know if there is a good answer to "how many lumens" you will need as this is more of a personal preference issue.  The chart below should help out (gives a comparative wattage from incandescent lighting to LED) if you are looking for bulbs and you could also use an LED dimmer switch that would allow you to adjust your lighting to fit your needs.  You can find the bulbs easy enough on-line  (e.g., Camping World, etc.) and you might even contact the factory (contact Elsie Miller) as they do have LED fixtures in their parts store that are easy to install and are very nice.  


Search the forum area too via "one word" searches for best results and additional information as energy consumption is frequently discussed here.  keep in mind too that things like USB ports and LED circuits do sap energy from a battery.  You might also consider installing a battery on/off switch for those times your trailer is sitting idle as this helps in preserving the battery during storage, etc.  

How old is your trailer battery?  If your battery has been allowed to run down below 50% and needs re-charging it does damage the battery over a period of time through a process called battery sulfation.  Maybe a newer battery is needed to ease the problem?