Monday, February 7, 2022

The Vandwelling House Battery Dilemma


Photo of my rig before heading out on my 2022 travels

I have a number of Vandweller friends that have similar  question/problem.

This problem is about having a house battery and sufficient power to do what they want without costing a lot of money.

I may be that they hey have a house battery already, but it is insufficient power to do what they now want or need.  On the other hand they may have a portable battery unit and also have the same issue of needing more power

There is no single answer to the problem of insufficient power for all Vandwellers.

Let’s take my current truck camper setup as a reference.  I use lithium Lifepo4 batteries only.  Lithium batteries are smaller and more light weight than a lead acid battery such as flooded, AGM or Gel Cell.  

Lithium batteries are not right for all situations.   lithium can’t be charged much below freezing temperatures or it may damage the battery.  I live in Massachusets and it’s cold, but I don’t use my camper in winter conditions.



When I leave on my winter travels, as I did this year, I don’t turn on battery charging until it’s warm enough.  My fully charged 50 ah Bioenno Lifepo4 battery gives me enough power until I get to warmer weather.  That’s right!  You can use the power from your lithium battery below freezing but not charge it.  Once I’m in the southwest I stay in the warmth and slowly work my way into colder Utah in March.  Although it can go below freezing at night temperatures are well above during the day and my camper stays warmer than outside.

First example:

This Vandweller spends time in below freezing climate and battery is packed so any heat inside van does not reach the battery, so they need a lead acid battery.  They have a 50 ah AGM battery.  A lead acid battery does not have fully usable amp hours, so you can only expect to get about 25 ah from a 50 ah battery.  This is not a lot of battery power but it is charged with solar and from the engine, which is good to get the battery charged again the next day.

Above is an example of a lead acid AGM battery on Amazon.  I have not evaluated this battery and this is no an endorsement for the battery

The question was can the Vandweller increase the amount of battery in the van and the answer is yes and I recommend a larger 100 ah AGM battery, above..  It’s significantly heavier and uses more valuable space.  It would give them their needed power at usable 50 ah. (Double the power they now have)  Basically what I have in my camper for power in amp hours.  The battery costs just under $200 and is not too hard to install.  The battery is a sealed type so no appreciable off gassing will occur.

Will the change run a compressor fridge, I was asked, and the answer is yes. 

In this first example the best solution for this Vandweller is to replace their smaller battery for this larger one in the example.  It’s not recommended to tie them together as they are not electrically compatible. If one wished to use bath batteries they would require electrical isolation for independent charging.  I wit be covering this in today’s post. You can tie like batteries and age together to overcome the compatibility issue.

I need to also say that if money was not a problem Renogy makes a lithium battery that has an internal heater to keep it warm below freezing so the battery is not a problem in the cold for charging.  But this battery is expensive, and priced out of the available funds for many.  I did want to mention it as someone out there reading this blog may find this helpful.



Second example

Another Vandweller friend has no house battery and can only charge things with the engine running.  They have a battery like the one below.  It is portable so bringing the battery pack to plug in to charge from house current is possible.




This batter pack above in the picture is only an example and not an endorsement. I have not evaluated it.  It is shown for reference only.

In this Vandweller case they like the flexibility of being able to have all the outlets and inverter nicely packaged.  It offers the ability to bring inside to charge if desired.  Since it’s portable it is easier to keep it above freezing inside the vehicle.

There are some drawbacks.  One is the rate of charge is slower than a separate battery tied to the engine. Another issue is that a fixed 12 bolt device like a vent fan has to be plugged in and out if charging elsewhere.  The good news is It can be charged from solar or from vehicle 12 volts as well.  Another good point is that if you camp in the shade you can take this portable battery unit out and put near a portable solar panel and charge where the sun is.

Note: I chose to show the model 500 as although a model 300 may work for minimal demand I suggest the 500 as Vandwellers often under estimate their power needs.

Although this Vandweller could put a fixed house battery in this portable unit will work for them saving the cost of installation, fixed solar and engine charging.  It gets a lightly built out van a head start from having to do all the wiring first.  It’s a great way to get started and try vandwelling, rather than investing in a build fore you know what you want.

My recommendation was to have both a lead acid battery hooked to engine through and isolator and use this for fixed lighting and fan, and use the portable battery unit for portable device charging and usage. With a fixed fan/vent and lighting it is best to have fixed wiring and switches, but certainly acceptable to live with the portable battery unit until you make long term decisions

Summary

There is not one design or solution for all circumstances of vandwelling. It depends on vehicle, needs, space, and money.  

Brent

macaloney@hotmail.com

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