profdant139 wrote:
Some of the preceding discussion is over my head, so let me bring things back to a more basic level. It looks like I will need an insulated battery box and a heater to keep the lithium battery above freezing. But the heater draws current, of course.
So I would have to budget a reserve of power in order to make sure that the battery is warm enough to accept a charge.
This may be a deal killer because we are almost always away from the trailer during daylight hours, hiking or snow-shoeing or skiing. So we would not be in a position to monitor the battery and the solar charger in real time, to make sure that we are not damaging the system and that there is enough juice to run the fridge, etc.
Hmmm. We may not be ideal candidates for lithium, until they work out the temperature issues. That is really too bad. But I am not ready to give up on snow camping.
Well, situations often differ, so in this regard I can only speak to my own situation…In my case, the OEM exterior battery box extended beneath the dinette seat, so I simply removed the nylon battery box, sealed and insulated the exterior door, and put two 200a/hr LFP’s in-parallel beneath the dinette seats..During unattended winter camping we leave the furnace set on 55d/f anyways (to heat enclosed basement tanks, dump valves and plumbing), so solar charging can be concurrent…
Example: Do to evolving needs over time (lol!) I’ve now expanded to having three separate solar PV systems (a 500w, 260w rooftops, and an occasional ground deployable 360w for longer desert excursions), each system having it’s own independent charge controller…
This may sound a bit haphazard :h yet in actual practice, by operating just one of the three separate systems (or some wattage combination thereof), I can reasonable project and plan for the expected amount of per hour harvest return while absent…
When enjoying extreme off-roading, the added charge flexibility here (regardless of season) has proven to truly be a major bonus, since I can reasonably plan for a desired amount of harvest!
FWIW, one of my controllers (the BlueSky) is programmable for voltage parameters and for timed duration at 100% SOC - so were I to opt for a FULL unattended charge (*however unlikely...) the controller would shutdown shortly thereafter…
* (unlike wet-cells, a routine ‘full charge’ is required only occasionally.)
Hope this helps,
3 tons
