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Solar help
#9
DC Compressor Fridge consumption is not a huge draw. Mine is about 32 watts running with a 55 watt surge for a half second when it first fires up and pretty much never runs more than 20 minutes per hour. Your Engel will be similar.

Induction cooktops are more efficient than regular heating coils, but heating anything using electricity, uses a lot of electricity. There is no way around that, and batteries simply cannot store very much.

Charging of batteries while driving is of course possible and should be utilized. However one is at the mercy of their vehicle's voltage regulator as to how effective the charging while driving is  The VR was not programmed to recharge an additional depleted battery, it was designed to keep a lightly depleted starting battery from overcharging, and as such it charges much slower than what the  battery owner  and depleted house battery itself would like.

All vehicles will vary widely as to how much electrical pressure (voltage) they allow, and for how long.  2/3rds more amperage will flow into a battery with 14.7v at battery terminals than will at 13.7v, but many vehicles will allow 14's only briefly then drop to mid 13's. A battery being held at ~14.7v is as fast as it can safely be recharged, 13.7v is a fraction of that and an unhealthy battery will never reach full charge at 13.7v, not even if held at that voltage for weeks.

The battery accepts as much amperage  as it wants, at the voltage reaching the battery terminals, upto the limits of the charging source.

Some more modern vehicles might intentionally allow the starting battery to remain only ~80% charged.  They do this to try and boost the MPG's slightly, at the expense of battery life.  It's Asinine really, but tiny percentages in fleet fuel economy means millions more in profit, for them, and everything this day and age is about maximum profit, Honor be damned.

If you can get 400 watts on the roof, do so, and get about 200 AH of AGM battery.  A PD 9245 or PD9260 or PD9270 converter would be great for the AGMS when you can plug into the grid. A 40 amp Renogy dc to dc charger/isolator will at least maintain 14.4 ish volts  while driving, whenever the house battery is not full or close to it.

 

These DC to DC chargers will both isolate house battery from starter battery, and take whatever vehicle voltage is allowed and step it up or down, though stepping it down will likely be a rare occurrence..  Renogy has new products in 20 and 40 amp flavors for doing this for significantly les$ than other products meant to do the same thing.
I've no experience with them, their efficacy or reliability.

The TPPL AGMS (Northstar/Odyssey) are second only to Lifepo4 in voltage retention under high loads such as an induction hot plate.  They will stand a much better chance of keeping the low voltage alarm on the inverter from screaming at you, and then shutting off before your food is cooked.  I would say get two group 24 or group 27 or group 31 batteries in parallel, with fat copper parallelling them and fat copper to the inverter.  Other premium AGM like Lifeline do not have the super high CCA figures, but they do want as high a charging current as possible at all times, like TPPL agms.  Lesser $$ AGMs do not have the same ability to hold high voltage under high loads as TPPL, but are better than most flooded marine or deep cycle batteries in this regard.

Beware than AGM is the new 'magic' battery, according to automotive forums and autoparts stores.  AGMS marketed to this crowd will have more attractive prices than any TPPL or Lifeline or even other AGMS marketed towards deep cycling, like Vmaxtanks on Amazon.  Yet these parts stores AGMS are primarly cost cut AGMS intended for starting duty only, even if their sticker says clearly 'deep cycle"  beware of marketing lies and deceptions, always.
  Do not expect the voltage retention or ability to accept huge charge currents and ultimately the same cycle life as a higher $$ AGM that is treated right. If the battery is not treated right then by all means go cheap as no lead battery is immune to improper recharging, or being regularly over discharged.

On another rv forum a guy has a large bank of minimum $$ Chinese AGMS, some 450AH worth, and now at 75% charged or less their voltage crashes  and his inverter shuts down entirley when he runs his toaster or microwave or Kettle.  These batteries are still fine for lesser loads and deep cycling, but are now inadequate for powering the higher loads when discharged below 75%, and this guy can and does recharge as well as possible with proper told devices and interest in doing so.  

Some people like a lot of battery capacity, then have way too little charging source for those batteries when they are well depleted
. I like minimal battery capacity and more charging capacity, but  here one enters the  specific intended use philosophical debate a billion variables, and  opinion, and I'll exit stage left.

Regardless AGMS that were discharged to the 50% range regularly need at least a 2 watts of solar to 1Ah of battery capacity in a good sunny environment in the hotter 6 months of the year, and preferably 3:1 ratio, and up north in the colder 6 months likely need well more than that, depending on the availability of other charging sources

Fear of propane will be expensive.
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Messages In This Thread
Solar help - by Cammalu - 10-06-2019, 05:21 PM
RE: Solar help - by RoamingRaven - 10-06-2019, 07:14 PM
RE: Solar help - by justjim - 10-06-2019, 09:30 PM
RE: Solar help - by sternwake - 10-06-2019, 10:58 PM
RE: Solar help - by Snikwahjm - 10-07-2019, 04:04 AM
RE: Solar help - by sternwake - 10-07-2019, 11:57 AM
RE: Solar help - by B and C - 10-07-2019, 09:24 AM
RE: Solar help - by tx2sturgis - 10-07-2019, 10:16 AM
RE: Solar help - by RoamingRaven - 10-07-2019, 10:21 AM
RE: Solar help - by RoamingRaven - 10-07-2019, 12:25 PM
RE: Solar help - by sternwake - 10-07-2019, 12:49 PM
RE: Solar help - by justjim - 10-08-2019, 01:33 AM
Solar help - by Cammalu - 10-08-2019, 03:38 AM
RE: Solar help - by rvpopeye - 10-08-2019, 04:36 AM
RE: Solar help - by Roadtripp - 10-09-2019, 08:36 PM
RE: Solar help - by justjim - 10-09-2019, 08:38 PM
RE: Solar help - by sternwake - 10-09-2019, 10:50 PM
RE: Solar help - by GypsyDogs - 10-10-2019, 05:03 AM
RE: Solar help - by RoamingRaven - 10-10-2019, 07:12 AM
Solar help - by Cammalu - 10-10-2019, 10:18 AM
RE: Solar help - by Abnorm - 10-10-2019, 11:03 AM
RE: Solar help - by justjim - 10-10-2019, 11:23 AM
RE: Solar help - by RoamingRaven - 10-10-2019, 12:14 PM
RE: Solar help - by GotSmart - 10-10-2019, 05:22 PM
RE: Solar help - by justjim - 10-10-2019, 09:11 PM
RE: Solar help - by GypsyDogs - 10-10-2019, 05:39 PM
RE: Solar help - by RoamingRaven - 10-10-2019, 06:40 PM
RE: Solar help - by Scott7022 - 10-11-2019, 05:30 AM
Solar help - by Cammalu - 10-11-2019, 05:51 AM
RE: Solar help - by justjim - 10-11-2019, 09:48 AM
RE: Solar help - by rvpopeye - 10-11-2019, 10:34 AM
RE: Solar help - by RoamerRV428 - 10-12-2019, 07:26 AM
RE: Solar help - by Roadtripp - 10-13-2019, 10:33 AM

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