Lithium Battery Upgrade to 320S

wolfeel2000

I am trying to decide on the size of Lithium Battery to upgrade to in my T@b.  What are the sizes that others have gone with and how do they work for you?  The only out of the ordinary power usage I have is a CPAP through a 12v plug.  Thank you all for your input.  I currently have the dealer supplied Interstate Group 24 battery that I think is 65Ah.  I also plan to upgrade from a 60 Watt solar panel to at least a 200 Watt suitcase.

Denny16

Others with the smaller TaBs, a 100 amp lithium provides more than enough power, and a 200 watt solar would keep it charged.  See MellowYellow posts about his 2014 TaB and a 100 amp lithium battery use.
cheers

Marceline

How much power do you need for the CPAP? I think that will be your biggest draw, so you should start from there. It's really hard to answer your question without knowing exactly how much power the CPAP uses.

Denny16

Good point Sharon.
cheers

Oyaji

Anecdotal evidence: 

I just took my 320S boondock on its maiden voyage, five days and nights in the high plains of New Mexico.  I have, in addition to the stock wet cell battery (probably 70aH), a 100aH Battleborn lithium battery.  And, of course, I have the built-in solar panel on the trailer itself--not sure of its rated output.

When I set up in NM, I connected the Li battery and isolated the stock battery, to be used as backup if needed.  

I was running the Alde every night (it was down in the 30's and 40's at night), the refrigerator all the time (gotta have lots of cold beer and pop in the high plains) and the roof fan during much of the day.  I wasn't running the interior lights much because at night I was either outside or sleeping. 

On the panel next to the door, the Li battery never showed below "full". And I never had to connect up my stock wet cell backup.  

The trailer was parked such that the solar panel was pointed generally NW.  The days were partly cloudy to full sun.  

Hope this helps. 

P.S.  Here is a little article on CPAP power usage:  https://truckersinsider.com/how-many-watts-does-a-cpap-use/

pthomas745

@Oyaji What were you using to monitor the battery?  The interior monitor "lights" were showing  you always "full" in the daytime because the solar panel was charging your battery.  Any battery and monitor will show "full" in every case if the battery is being charged, no matter what the source.

If you have installed solar, have you found the Victron App?  It will show you battery readings that are a lot more useful.

You probably are in good shape on your setup as far as power goes, but a better battery monitor will show you a better look at your usage, especially at night when the solar is not charging.  You don't say what fridge you have, and it sounds like you are up on CPAP usage, but your overnight usage with both those items would be something good to know.

https://www.victronenergy.com/panel-systems-remote-monitoring/victronconnect

Denny16

With our TaB400 running the AC/DC fridge, day and night, Alde and lights at night, radio for an hour or so, we never went below using 35% of our 200 amp battery, so we used around 40-60 amps per day (using Victorn battery monitor), but that was recharged during daytime back to full charge, with the solar panels (in part shade under a small tree).  

A TaB 320 or older  TaB is going to use less energy yet.  The CPAP will probably be the biggest nighttime draw.  Once you work out how much the CPAP uses, you can work,out your total power requirements for a 24-hr period.
Cheers

Oyaji

pthomas745 said:

@Oyaji What were you using to monitor the battery?  The interior monitor "lights" were showing  you always "full" in the daytime because the solar panel was charging your battery.  Any battery and monitor will show "full" in every case if the battery is being charged, no matter what the source.

If you have installed solar, have you found the Victron App?  It will show you battery readings that are a lot more useful.

You probably are in good shape on your setup as far as power goes, but a better battery monitor will show you a better look at your usage, especially at night when the solar is not charging.  You don't say what fridge you have, and it sounds like you are up on CPAP usage, but your overnight usage with both those items would be something good to know.

https://www.victronenergy.com/panel-systems-remote-monitoring/victronconnect

Like I said, my post was anecdotal.  I wasn't recording daily usage.  

I primarily used the panel lights--which of course are only a quick-n-dirty check.  And they showed "full" day and night.  Had they not, I might have performed a more exacting analysis.  However, I also checked in with Victron from time to time just to make sure that all systems were "go".

The fridge is the compressor fridge that comes with the 2021--apparently, it is very energy efficient.  But if one has a concern in that regard, it is a simple matter to run it on max cool (7) during the day and turn it down to minimum cool (1) during the night.  Back in the day before I had the T@b and was sleeping in my van with a Dometic cooler  (also with a compressor) and a standalone 100W panel, I'd run the fridge at 30 deg. F during the day and turn it off altogether at night.  

Long and short, was very impressed with the way the 320S Boondock and Victron system worked with the Li battery.  I wish I could say the same about the gas stove, which didn't work at all, although it worked fine before I departed for the high plains.  I'll be taking that issue up with Nucamp.  

pthomas745

@Oyaji Obviously, you have a good handle on the fridge behavior.....and the behavior of the "panel lights."