Lazy Daze Owners' Group

This tech talk is mind numbing for the beginner I am. I was not told at LD when they installed a couple of AGMs how to care for them. Repeatedly draining them has rendered them unable to hold a charge for long. Purchased two Amperetime 12v 100 Ah and was going to just drop them in. Not so fast. It may or may not damage the '05 E450's alternator,  I may or may not need a DC to DC charger which may or may not overheat, the onan generator may or may not fully charge them, and the 220 watts of solar panels may or may not be enough to charge them either and the whole godamn thing might or might not
 burst into flames if I dont install the proper isolating diode flowing through a double ought cable that y's to all the components simultaneously during low voltage charging but not high voltage charging which requires a completely different fix. WTF?  Does anyone have simple solutions for the simple minded?

Ann, I like Steve's advice: disconnect the alternator charging line and just use your solar panels and (when necessary) generator to charge the new batteries. That will eliminate a lot of your worries.

A couple of things to keep in mind. First, lithium batteries don't like temperature extremes. They'll be damaged if charged at temperatures below 32° F (0 ° C). Ampere Time's built-in circuitry protects the battery against "overcharge, over-discharge, overcurrent, and short circuit," but they don't say anything about preventing damage from charging when freezing or colder. So if you're going to mount these in an outside battery compartment (you didn't say what model/floorplan you have), you need to be very conscious of that.

You can do a couple of things to reduce the risk. Since lithium batteries don't need venting, you can block the vents on that external battery compartment door to keep out cold air. Do it with an insulating material such as Reflectix. And consider cutting an opening in the inner wall of that compartment, so that in cold weather, some of the warmth of the interior will get through.

Moving the lithium batteries indoors, as Harry suggested, would be even better from a temperature standpoint... but that's a major modification that you may not want to undertake. And running dual sets of batteries as he does is not simple (as I believe he recently commented elsewhere).

Second, if your '05 Lazy Daze has the original converter/charger, that's not the best (or fastest) way to charge lithium batteries. You may want to consider having it replaced with a more "intelligent" converter from Progressive Dynamics. You can find recommendations for which model is best elsewhere in these discussion threads. It will be kinder to your batteries, and will also charge them faster, meaning less generator run time.

One last thing: it's not hard to damage batteries if you don't have a good idea of their state of charge, and the multicolored LEDs that Lazy Daze provided in your '05 are about as useful as a gas gauge that only reads FULL or EMPTY. I'd strongly recommend adding a good battery monitor such as Victron's BMV-712. It will give you an accurate reading of the battery's level, so that you can know when you're getting dangerously low.

This electrical stuff can sound complicated and intimidating. Many of us are still figuring it out in our own ways. If you prefer not to deal with it on your own, AM Solar up in Oregon has a good reputation, as Keith mentioned.

This looks to be a good basic meter that could be used to monitor your batteries.  Amazon.com: Renogy 500A Battery Monitor, High and Low Voltage Programmable...
   The price is reasonable and will tell you what is going on with your new batteries.      RonB