Lithium Upgrade vs External Battery Pack for a Solis 59PX

[jonc123]

Hey everyone,

I’ve got a new-to-me 2022 Solis 59PX with the stock AGM batteries. I’ve been looking to see how I can get more days off shore power either keeping the existing or potentially replacing them with lithium. I already swapped the stock PWM for a Victron 100/30 MPPT which does a great job keeping the batteries up during the day, and I have no issues running everything. They sit around 12.5-12.55V in the morning after resting with no shore power, but if the fridge is running all night, they will be at 12.0V or even less by morning (this also causes the Truma to act up).

Other than the fridge and Truma, I’d like to run a Starlink Mini and charge my laptop. I’ve been carring 2x288Wh chargers to keep the laptop charged, and sometimes the Mini plugged in. Obviously I have the gas generator that I can use, but when needed, I’m looking for a quieter solution.

I’m torn between two setups that I think would work:

1. Grab an Anker C2000 (2048Wh) with the RV hookup and call it a day keeping the stock AGM until they completely die. Cost: < $800. Can plug needed things directly into it or use it as overnight shore power. Can also get an expansion battery for an extra $500 that doubles the capacity.
2. Pull the AGMs, replace the alternator charger with a 50A DC - DC Orion charger and go with LiTime 165Ah self-heating and a shunt vs. the 100Ah Victron connected batteries. Is the extra capacity of the 165Ah heated batteries worth losing the Victron communication? Still need to run the generator for AC or spend more money on a 12v AC. Cost: close to $2000 for lithium install since I’d need some paid help installing it and that doesn’t include swapping the AC.

I live in the South but spend 2-3 weeks up North in sub-freezing temps, so I’m worried about the batteries being exposed under the rig. When up north, I will have access to shore power most of the time.

Do I need to worry about anything else in the van if I make the jump to Lithium? Is it better to simply use an external generator + the built in generator when appropriate?

Thanks
Jon

 

[Bnystrom]

If you're going to run your A/C off of batteries, you need a lot more capacity. The general recommendation is at least 400Ah and even that will only get you a few hours. A 12v A/C unit isn't going to help much and you'll have to run heavy wiring up to it, which could be really difficult.

If you buy a good quality battery, it will come with Bluetooth capability and a phone/tablet app that makes a shunt unnecessary. I don't know the dimensions of the Solis battery compartment, but there's a reasonable chance that a pair of SOK 206AH batteries will fit. You may even be able to fit a pair of SFK 315Ah batteries. They have a video on their site of a pair being installed in the stairwell of a View. Almost three years ago, I installed a pair of their 300HP batteries in our View, under the dinette seat, and they've been great. If you still want Victron connectivity, SFK batteries have it. They also built and serviced here in the US.

 

[klook]

You don't say how you are going to charge that massive 2048ah device or double that. That takes many many panels.
I think Bnystrom has the right idea. You can add other things as you go if you build it out right. I just added a 314ah Wattcycle to my class C to join 2 100ah Wattcycle already installed. That is more then I need but within my panels ability to charge them. I have 4 330w panels. The new batteries are incredibly small. My 314ah is 15.12 × 7.64 × 9.76 inches.

 

[Bnystrom]

You don't say how you are going to charge that massive 2048ah device or double that. That takes many many panels.
I think Bnystrom has the right idea. You can add other things as you go if you build it out right. I just added a 314ah Wattcycle to my class C to join 2 100ah Wattcycle already installed. That is more then I need but within my panels ability to charge them. I have 4 330w panels. The new batteries are incredibly small. My 314ah is 15.12 × 7.64 × 9.76 inches.

It's 2048Wh, not Ah. It's a 160Ah battery.

 

[klook]

Ah, that would do it. So, what are you going to charge the 320ah batteries with?

 

[jonc123]

There is 220W solar on top with a port to accept another 175W, shore power and the alternator. Already have the DC -> DC charger for the alternator, upgraded from PWM to an MPPT solar charger, and will install a shunt with a temperature probe and upgrade the shore power converter since it doesn't adjust to lithium. I ordered two 165AH batteries, Group 31, self heating that will slide into the existing. I'm installing the batteries, charger and shunt this week, and will install the converter when it gets here (the existing is disconnected for now). Both batteries have a BMS with Bluetooth, but everything else is Victron, so I also wanted to get it all in the Cerbo so I could see what was going on when not right at the van.

These batteries just need to run a fridge, charge phones/tablets/low power laptops (MacBook Air and Snapdragon devices) and Starlink without me worrying that the AGM will be done by morning. I will be connected to shore power most of the time or I have the built in gas generator under the van as well. I decided that if I really need that AC working off batteries, I'll tackle that separately.

 

[klook]

Ok, rule of thumb is 200 to 300w for each 100ah of battery. Driving and the generator will top them off though, and it depends how far you deplete them if that will be necessary. Sounds like you have it well in hand. Victron is great stuff. Running AC off batteries is very difficult, but you have a small space so........I decided to stop short of that also with a 31ft Class C.
I had 300ah and 990w of solar in Arizona this winter and it worked great. No AC used.

 

[jonc123]

Thanks....I saw the 200-300w for each 100ah, but I'm hoping with the relatively small load, and the other options of topping it up, that I'll be good to go. I'm not living in it, just using it for weekends, or at most, a week per month, and during those times, it will become my primary vehicle, so figure I will easily top it off. I decided that the 2 weeks when I'm up north in the winter, I'll kill the power completely, stop all charging and just bring a small power bank I already have. When I get back to NC, I'm good to go. At home, I will have it connected to shore power.