Battery upgrade, maybe solar option also

[Quint_Da_Man]

Trying to learn a little bit about battery upgrades including a solar option.

I have a 2020 Thor Class C, it has 2 house batteries. Last year we joined Harvest Host and did a little more boondocking than usual. I found that the house batteries seem to drop below acceptable levels in about 4 or 5 hours of light duty use (TV and a few lights for a couple of hours). What happens is all the electronic devises hooked up to the battery system I.E. CO2, Leveling system, Fire alarm all start beeping at around 2am. The only thing that is running after around 10pm is the refrigerator and those smaller electronic devises. I've researched lithium battery upgrades and that doesn't seem to be an option because of their limitations in cold weather (below 40 degrees). I live in Massachusetts and early spring late fall camping have many a night below freezing. Another option from my under standing would be AGM batteries these seem to be better than standard batteries but not as good as lithium. I have also had priced out a solar option. My rig is solar prepped so the upgrade would be 4 AGM batteries and two 150w solar panels for about $4500.00 installed. That was a lot more than I expected. Now I'm thinking about maybe just upgrading to 4 AGM batteries and hope they will hold charge at least long enough to get through the night.


I'd love to hear peoples ideas, and options, things they have done. We plan on doing a hell of a lot more boondocking in the near future so would like to resolve this issue.


Please educate me.


Thanks

[KD4UPL]

$4,5000 is a huge price for 2 panels and 4 batteries. A 150 watt panel should only cost about $150 each. A group 31 AGM is about $350 each. You'll need a charge controller for maybe $400. That's $1,750 worth of major parts. Throw in $250 for mounting brackets and wire and they're charging you about $2,500 for the labor.

I'd make sure your converter is really charging the batteries fully. It's probably not as most converters are fairly poor.

I don't believe lithium is worth the money for most people and the cold temperature limitation is a problem. I install off grid solar systems for a living and I rarely use lithium batteries because most mountain top cabins go unused and unheated all winter.

[2oldman]

theoldwizard1 wrote:
Best place to get an education is no DIY Solar Power with Will process on YouTube.

Will Prowse

[2oldman]

Tom/Barb wrote:
powered by a victron 3000 amp inverter.

watt

[Tom_Barb]

Simply remember.
A lithium batteries can be discharged to 90 % of it's capacity, while a Lead-acid can only discharged to 50% of its capacity. lithium can be charged to 100% while lean-acid will only be charged to 10% of their capacity.

which tells us that 4 - 100 AMP lithium batteries will provide 360 amps. while the lead-acid will only provide 200.
Lithium batteries don't corrode , plus the lithium are good for 10 years of service.

[Tom_Barb]

E-mail me I will show you what I did for a lithium battery upgrade.
4 ,, 100 amp hour battelborn batteries,
powered by a victron 3000 watt inverter.( corrected)

this will proving about 4 days of battery power.

due to the different charge rates you must separate the lead acid chassis batteries and the lithium house batteries, then provide a charing system for the chassis batteries.

a 2-5 amp charger should be enough to keep the chassis batteries charged while the coach is idle.

I also installed a 30amp DC to DC charger to charge the house while the engine is running.

we have the system in service for about 1 year, 0 problem so far.

nc19143 @ Comcast. net place "battery options" as the e-mail subject..

[otrfun]

3 tons wrote:
. . . Be advised that if you have a Progressive Dynamics charger, you might simply add their optional Charge Wizard dongle… For Lithium, simply switch the dongle into the 14.4v Boost mode / no need for an upgrade . . .

Excellent advice! There is nothing magical about these so-called "lifepo4 approved" converters other than the slightly higher 14.6v bulk charge voltage. Any quality, late model 3-stage 13.2v/13.6v/14.4v lead-cell converter will safely charge a lifepo4 just fine. Zero downsides. In fact, there's one important upside to using a 3-stage 13.2v/13.6v/14.4v lead-cell converter vs. any single-stage 14.6v lifepo4 converter: zero chance of overcharging.

[Lwiddis]

Lithium batteries provide a smaller and lighter package with a lifespan longer than wet cell batteries with more available amp hours at a good voltage. No, you can't charge them below 32F but you don't need to charge them full every day either. No water to add or check...no terminal cleaning. However, four AGM batteries should easily hold you through the night. Something in your system is bad.

Regarding solar, I haven't run my generator in 45 days of camping except to "exercise" it. Solar is wonderful...install and forget about power. You'll have it.

[theoldwizard1]

WNYBob wrote:
When up grading batteries check to see if your converter is up to the task of charging them. AGM and Lithium batteries take different charging rates and voltages! Yes, another cost, but don't damage the new batteries.

If you need to upgrade the converter then now would be a good time to get rid of it completely !

An inverter/charger/automatic transfer switch can replace it.b Easy to install and even easier to use !

[3_tons]

Quint Da Man wrote:

WNYBob wrote:
When up grading batteries check to see if your converter is up to the task of charging them. AGM and Lithium batteries take different charging rates and voltages! Yes, another cost, but don't damage the new batteries.

Thanks I'll look into that.

I was just up in North Tonawanda this weekend. My rig is at Colton RV as we speak. That's who will be doing the upgrade if I go forward wit it.

Be advised that if you have a Progressive Dynamics charger, you might simply add their optional Charge Wizard dongle… For Lithium, simply switch the dongle into the 14.4v Boost mode / no need for an upgrade…


BTW, in nominal terms, one 100a/h LFP is roughly equivalent to two Lead Acid batteries…

3 tons

[theoldwizard1]

Quint Da Man wrote:
I've researched lithium battery upgrades and that doesn't seem to be an option because of their limitations in cold weather (below 40 degrees). I live in Massachusetts and early spring late fall camping have many a night below freezing.

Lithium is THE ONLY WAY TO GO ! Many batteries actually have heaters built in so that you can use them below freezing.

Best place to get an education is no DIY Solar Power with Will process on YouTube.

[3_tons]

The problem of which you describe tends to point to the common effects of voltage sag… Lithium (due to a nearly flat discharge voltage profile) is ideally suited to overcome this common problem … Understand too that cold temperature charging (charging at or below 32f) doesn’t prevent continued discharge down to about -04f… Temps can often rise by the early afternoon, and LFP’s far deeper DOD (depth of discharge) over Lead Acid types will often see you through to the next available harvest cycle…Yet some manufacturers offer LFP’s with charge protection shutdowns and some with built-in heating elements that activate when charging, and you could always opt for a battery heater blanket, or even an indoor mount, thereby repurposing your battery box for additional storage (what I’ve done)…

3 tons

[2oldman]

300w of solar will be just barely enough for any normal use, especially if you have an inverter. Installing the panels on the roof yourself is not that difficult and a whole lot cheaper if you're physically capable. And it's a CO monitor, not Co2.

[Quint_Da_Man]

WNYBob wrote:
When up grading batteries check to see if your converter is up to the task of charging them. AGM and Lithium batteries take different charging rates and voltages! Yes, another cost, but don't damage the new batteries.

Thanks I'll look into that.

I was just up in North Tonawanda this weekend. My rig is at Colton RV as we speak. That's who will be doing the upgrade if I go forward wit it.

[WNYBob]

When up grading batteries check to see if your converter is up to the task of charging them. AGM and Lithium batteries take different charging rates and voltages! Yes, another cost, but don't damage the new batteries.