[quote="Tony']
There is a charger in the camper, when we are connected to shore power or when it's connected to my truck, the batteries are recharged. If we add the new batteries, are you saying the charger may not do a good job of recharging it?
Lowd.....does it use a lot of propane when I use that method? I haven't found any data on how much it consumes while running the fridge.
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the "charger" in your camper is not even doing a GOOD job of charging the battery you have. if you are going to charge your batteries from a generator you will really benefit from having a power factor corrected charger that is capable of a constant current bulk charge phase followed by a constant voltage absorption phase and then go into a constant voltage float phase.
the good charger will allow much quicker recharge times regardless of battery chemistry.
the power factor corrected charger will allow you to run almost 2 times the size battery charger on the same generator and with the same fuel consumption. someone mentioned above that a 1000 watt generator was good for about 35 amps of charger. with a good quality powerfactor corrected charger you can run a 60 amp constant current charger while burning the same amount of fuel it would take to run a 35 amp NON-powerfactor corrected charger. i run a pronautica promariner 60 amp charger from my honda 1000i inverter generator.
with your existing fridge, if it is working ok. run it on propane when away from "shore power" like when you are camped out with no place to plug in or not driving. you can switch to 12 volt while driving and if someplace where you can plug in then switch to the 120 volt. if this fridge does not work good enough. adsorption type fridges are notorious for not working well. especially if they have been used imporperly in the past or you use them improperly like not being level. then i would look at replacing with a compressor type unit, either 12v dc or 120v ac (would need inverter)
while lithium batteries are the cats meow, and if you can afford a high quality drop in like the battle born or the trojan trilium units you will probably be pretty happy. if you have not already or plan on researching alot and possibly making some mistakes and ruining a few lithium batteries (expensive learning curve) then i would not suggest do it your self till you have more knowledge/experience
the lithium batteries will charge quicker, are much lighter and do not degrade if left at a partial state of charge (failing to fully recharge after discharge) but it does come with sticker shock $$$
the firefly carbon foam AGM batteries are a mid ground. not as big a sticker shock but also do not degrade from partial state of charge abuse
but the reality is that if you can run your fridge on the propane, you may be happy with what your existing battery can do for you. especially if you get to where you can charge it fully. either from solar (highly recomended) or from a good battery charger on the generator
as an example, i recently installed 100 watts of solar on a roadtrek with propane fridge. even though they did a lot of driving they could never get their rv battery (house bank) fully charged and it would often run low in the night from lights/laptop/fan and such. now with the 100 watts of flex solar mounted on the roof and a quality mppt charge controller and still using the existing battery she is having much more power through the night and getting the battery fully charged on most sunny days.
another example i am working on for a customer as we speak is an older westfalia vanagon. we have replaced the propane fridge with a 12v dc "truck fridge" and added 225 watts flex mobile solar with cheap PWM controller for testing. this set up is keeping up with electrical demands to run the fridge and even freeze a water bottle in the little freezer compartment. this is with the old rv battery it came with. and the battery keeps the fridge just fine over night and the solar has the battery fully charged by the time the sun starts slipping behind the trees. and this is in oregon in NOV, pretty low sun angle. we will be upgrading the solar charge controller to a quality (victron) mppt unit and the battery to a pair of golf cart lead acid batteries. that will make for a very robust system
as for your unit not having an inverter, my suggestion is to see how hard it would be to convert the 120v ac only devices to 12v dc so you dont have to buy and deal with the idle consumption of an inverter. but if an inverter is needed. there are lots of options out there. just make sure to calculate your needs so you get the right one. some of the better inverters can be had as combination inverter/chargers. aims power and victron are 2 that i know of that have power factor corrected chargers built into some of their pure sine inverters. i prefer the victron, but the aims power are probably less than half the price.
if you have questions or dont understand some of this, feel free to contact me via pm and i can work one on one with you
good luck and welcome to the club
