BLITZEN goes Lithium

[Trail Talk]

During our ice road trip this winter (Ice Ice Baby 2023) we experienced a bad shore power connection that cooked our Victron AGM batteries. There were a few lessons learned and the incident accelerated our plans to install lithium house batteries. It was always in mind; during our winter months when solar is virtually nonexistent and shore power almost impossible to find, who can argue with more power and less weight?

The hunt for suitable batteries was shaped by our goal to at least double the AGM power while staying within the existing battery compartment. The field is pretty crowded but, in the end, we found a local supplier of Canadian-made Discover Lithium Blue batteries at very advantageous prices, so the choice was made for two of their 200Ah LiFePO4 batteries, giving us effectively a 210% increase in stored energy over the AGMs and 110lb weight savings.







Our rig went off to Overland Explorer Vehicles for the swap and installation of a DC to DC charger. We went with Victron for their bluetooth app which already connects to our solar charge controller and battery monitor. Once the old batteries were pulled, I was surprised to see how the AGM cases had bulged from the previous incident.



Of course, the new set-up had to throw us a curve ball. After driving home and checking the battery's BMS app, I was alarmed to find that one had gone into an over-voltage shutdown. The battery reset itself after bleeding off some power with an electric heater and I plugged into shore power. The next day I found another over-voltage shutdown! Following a deep-dive into all the settings for the DC to DC and our inverter/converter, I discovered the default lithium battery profiles provided a bulk charging current too high for the BMS, triggering the over-voltage protection. Once corrected, all went well.

With one weekend's camping experience, we were amused to see the battery monitor predicting 10 days reserve power with full batteries. We also used less propane, opting for the electric kettle to heat water. I know, its a slippery slope...

 

[waveslider]

We believe the best training we had for our current vehicle (which sports ~380 aH of battery and 98 gal fresh water) was having our SMB van for 12+ years with like 11 gallons of water and 100ah battery. Your early AGM experience will serve you well.

I have done a host of electrical upgrades over the last year including adding a 7th solar panel (1400w total) and adding a second alternator charging appliance which allows me to siphon up to 80 amps off the alternator to charge the lithium battery bank. Previously it was only 40amps. So now I ALWAYS have a generator with us - the main truck engine.

But on a recent hunting trip it never got past noon before the batteries were back to 100% under solar even on cloudy days so I think we are set now. In retirement (coming soon) we will definitely find out just how long we can go unsupported. The learning curve you are on with these upgrades will benefit you greatly I would think. Similar projects like this has benefited our understanding and experience tremendously.

 

[Trail Talk]

Thanks for that reassurance We've considered, on and off, adding another solar panel but then winter hits and solar drops to nothing. Can't beat that free energy, though!

Another small but useful upgrade recently was to replace that %$#& twist-lock shore power connection with a SmartPlug.

 

[waveslider]

Yeah, aside from when the truck is parked here at the house we really don't camp anywhere with plugins/shorepower but I ONLY use the collar-locking shore power plug that is more stout - for the reasons you likely encountered. But I would MUCH prefer that smartplug configuration if doing it over. That seems a lot less prone to failure.

When we built our truck, we purposefully left a spot on the roof open for a potential addition of an AC unit if we decided that we wanted one. We quickly decided that there is a reason we put our house on wheels and if it's too hot and we need an AC, we just go somewhere its cooler.

So we had an opening for the additional panel and put one in precisely for winter (less daylight/more clouds) and I'm hoping that it will be enough to push through several days of clouds and still draw enough. But then again, we have a lot more roof space than you do ☺️

The charge profiles are so important yet seemingly so easily screwed up on the Mastervolt and Victron stuff it almost makes you wonder.

Just last weekend installed front air bag suspension on our truck - boy howdy that's a whole nother level of work. Like playing jenga with 2 ton blocks. lol

 

[Trail Talk]

If we decide on a third panel, I’d also seriously consider tilting panel mounts to better track the much lower winter sun. How to make the operating mechanism convenient will be the challenge. OTOH, we travel in the upper blue and dark green regions of this diagram, so it may be a waste of resources to chase solar power…

 

[waveslider]

True. I was really shocked by just the difference here in the lower 48 the impact it makes just on the shoulder seasons alone - much less full on winter.

The technology I'm watching with great interest - even though it's unlikely I will live long enough to see it come to fruition - is the small scale wind turbines for RVs and small vehicles. I think those are going to be a game changer.

 

[Trail Talk]

The technology I'm watching with great interest - even though it's unlikely I will live long enough to see it come to fruition - is the small scale wind turbines for RVs and small vehicles. I think those are going to be a game changer.

I was interested to see this wind turbine trailer that is being used by poletopoleev.com. Unfortunately they decided not to bring it on the northern leg of their journey to Yellowknife, NWT, this winter due to...a lack of wind! That and the energy cost of towing anything ;-) They even sacrificed in-car heat to save battery power.

 

[waveslider]

This is more the design style I’m interested in following.

 

[Trail Talk]

Also considered, then eliminated, was the need for heated lithium batteries. We keep our cabin above freezing during winter storage with an electric space heater and switch to hydronic heating while camping or travelling. With the batteries mounted inside the cabin and the BMS set to discontinue charging at battery temps below 5C, we should avoid any chance of damage.

 

[Trail Talk]

Aside from all the well-known advantages of converting to Lithium batteries, we did lose a bit of functionality :-(

Due to the incompatibility of our LiFePO4 house batteries and the lead-acid truck batteries (the same reason we needed a DC to DC charger) our Samlex dual-sensing voltage relay became redundant.

The Samlex would allow shore power to first charge the house batteries, then the truck batteries. It further prevented either from draining the other side. Now our dual truck batteries are removed from the charging mix.

Not sure yet if that will prove a disadvantage during freezing weather, but "experts" say that a fully charged battery is the best protection vs battery warmers.

Has anyone found a means of retaining the truck battery charging from shore power while using lithium in their house?

 

[waveslider]

I know at least a few people that simply plugged a 120v battery charger into their rig and connected it to their truck battery so its charging/floating while on shore power. They simply dedicated it into the system, hid it in a far away compartment and that was that. Most new battery chargers (NoCo brand, etc) you pick what battery type you have (Lith, AGm, LA,etc) and just leave it on.

If you were concerned about the potential for the drawing down the house battery when NOT on shore power, then you could either switch off the outlet that the charger is plugged into or put a switch somewhere closer to the leads heading to the battery (although I suspect the first option would be best since the chargers probably have SOME amount of parasitic drain.)

However, didn't you say you were running Victron equipment in there? I suspect Victron is similar but our Mastervolt Inverter/Charger has a second charging output available that is specifically for charging starting batteries, etc. You might check your manual on your Victron and see if that is also an option. It's basically the same setup as I described above but with one less component. I hooked ours up and put a switch on it and only actually use it when parked at home for long times.

I carry a charger/battery jump starter in our rig for the odd chance we need to charge our truck batts from the house inverter or to jump them. (Needed it once!)

I would check my Victron inverter/charger stuff first though. That would be an easy fix.

 

[Trail Talk]

We still have our original Xantrex 2000w inverter/charger which doesn’t have the additional charging output you mention. If we upgrade to a 3000w unit I’ll be sure to look for that feature.

What I do have is a nice little Victron 15A blue smart charger used to prep the new lithiums prior to installation. Ideally I would need a way to automatically feed it 120V while on shore power.

Edit: well that brings us back to another AC output on the inverter/charger…

 

[Trail Talk]

We still have our original Xantrex 2000w inverter/charger which doesn’t have the additional charging output you mention. If we upgrade to a 3000w unit I’ll be sure to look for that feature.

Apologies for quoting myself :-( Looks like the Victron Multiplus II would suit, having a second AC output that only switches on when AC power is available.

But I'm drowning in the details on Victron's website. GX or non-GX? I rarely see a signal where we travel so local monitoring and configuring without internet connectivity is a must.

 

[waveslider]

Yeah, I'm certainly NOT a Victron expert. I have - out of necessity - gotten pretty good at programming and troubleshooting Mastervolt equipment and I have nothing that requires a signal to do ANYTHING. All of my programming - using the Mastervolt software- happens through the dedicated cheap laptop that I carry in the rig at all times. The only two purposes that laptop serves is the Mastervolt programming software and it (now) also holds the engine troubleshooting software to use with the NexIQ diesel ODB/ODBII adapters to read any errors on our truck when out in the middle of no where.

It is definitely nice to pull up the Mastervolt software and check/adjust things if needed.


About the only thing I wish that was connected in our truck was the Webasto furnace/water heater because there have been a few times when I wish we could turn on the hot water while
hiking back to the rig so it was ready when we got there. But then I realize we are rarely in a place where we have a signal so it would just be an extravagance we couldn't use regularly.

 

[Trail Talk]

I've heard good things about Mastervolt but their inverter/chargers with two AC outputs (Combi Ultra) are all 230V. Seems they don't have NA in their sights for this product.

They do offer single output 120V models in the CombiMaster line but that doesn't get me where I wanna be...