We have sold the Diesel Generator from our Motorhome and replaced it with a Large 70 Gallon Water Tank and a small portable Honda Generator for emergency charging.
The Generator weighed 420 Pounds and the Water tank is only 50 Pounds empty and around 560 when full of water. We do not plan to drive long distances with the tank full it is mainly when going out to a boondocking site. We have now used the tank 3 times and each time has the 90 Gallon in the RV and 65 Extra gallon been enough to stay for 14 Days. After 14 Days is our Black tank full and we really need to go dump and refill anyway.
The tank is not plumbed as part of our current water system. When the regular 90 Gallon tank gets low is a small pump used to transfer the water from the new tank to the regular freshwater tank.
This is the same water pump we have used to transfer water from our bladder, transported in the Jeep, to our regular tank. In the future can we add a regular hose adapter, but I do not think this is necessary with the current solution working fine.
To ensure we still have an option to charge our batteries in an emergency (we have not needed that the last 3.5 years) have we purchased a Honda Gas Generator. This Generator is only 56 Pounds and is stored in the trailer and has already been used by another RV with a broken generator. Our old generator was only a hassle for regular exercise and pay for oil changes. The new Honda is not very big compared to our old Diesel Onan 7.5k.
Moneywise was our Diesel Onan Generator sold for $4000 (730 Hours). The water tank was $150 and $150 shipping. The Honda Generator $1100. So we gained $2600 on the deal and got something useful.