Thor Forums

[Chance]

Originally Posted by JamieGeek

Typically with Lithium only coaches they put another alternator on the main engine to aid in charging up the batteries. Thus you wouldn't have to drive somewhere every 4 days, just run the engine for some time. The bonus here is that the main engine is usually a lot quieter than a generator.

Its nice to see the general Li-Ion battery price drops making it to RV options as well..

Exactly. As we’ve discussed previously, one of the remaining technical challenges is how to charge batteries back up quickly. Weight of lithium batteries for house use isn’t much of a problem, battery costs are coming down to “reasonable” levels, and many new buyers want large inverters anyway, so the missing piece of the puzzle is how to get 800 Amp-hours or more of batteries charged back up in a short period.

The two main sources of power for these types of rigs are often a 280 Amp alternator (do not know its continuous rating) and a large inverter/charger with high-capacity charging. Solar for charging such a large battery bank seems too slow to contribute much.

For us, if overnighting at campgrounds every few days (which we would do), an inverter/charger can get 800 Ah batteries back to 100% on shore power.

If touring or traveling daily, the alternator can charge battery bank in less than 4 hours after running air conditioner overnight, so not a problem with that need.

The only scenario that still makes this type of system impractical for us are the few days a year we’d want to boondock while running air conditioner. As long as alternator is limited to a little over 2,000 Watts, and A/C requires half that much power, the engine would need to idle 50% of the time, and I don’t see myself doing that.

Since 800 Ah of lithium batteries can accept 400 Amps of charge current, I’d like to see that much (equivalent) from dedicated alternator. To be practical, it would likely need to be 100 Amps at 48 Volts nominal.