Best solar panel values and best battery values

[user 29855]

Hi,
My engine seized up on a cross-country trip, and I'm now starting all over on a new van.
My last van had a pair of 100-watt panels, and and a pair of 6-volt golf cart batteries. although I was able to live within those power constraints I wouldn't "object" to more (and more, and more....)

The batteries that I had are no longer available, so I'm looking for recommendations from folks who have actually used products themselves. I'm not interested in Lithium batteries because they are well beyond my budget.

Any help is really appreciated..

Geneeus

 

[Sofisintown]

I have a pair of AGM 55 AH each in parallel (110AH total) I think they were about $120.00 each at Walmart.
The100AH are too heavy for me. I fed them from a flex 100 watt panel, which died, and I am replacing with 2 Newpowa rigid 100W mono. $192 for both, delivery AND 8 brackets with screws included.
So, this is a secondary system.
I use for most of my needs a Bluetti 200, that gets charged from the pair of batteries.
I don't charge the Bluetti from the panels, because it wants 35 volts minimum to charge directly, (that would be 3 12volt panels in series) but it will charge from the battery.

 

[Spaceman Spiff]

These are your best values IMO:

Solar:

Used commercial take offs or surplus if you can find them locally and can handle the size and weight.​

A number of companies will ship 100W panels free or pick up in local store.​

Flex panels are expensive for what you get.​

Batteries:

GC2 FLA batteries are the cheapest (cash outlay and long term) if you can handle the weight and minimal maintenance.​

A number of people have gotten good service out of Walmart Marine batteries.​

If you can build your own, DYI LiFePO4 battery is not much more expensive than AGM.​

I run 2 X 100W Renogy rigid panels and 2 X 208Ah GC2 FLA batteries. I am usually < 80% in the AM and 100% by noon running electronics, LEDs, refrigerator. My system is 8 years old.

 

[frater secessus]

My last van had a pair of 100-watt panels, and and a pair of 6-volt golf cart batteries. although I was able to live within those power constraints I wouldn't "object" to more (and more, and more....

If you are still road-tripping the cheapest/easiest way to get more and more is with alternator charging doing the heavy lifting and solar doing the high-voltage, long duration work. My reasoning.

Best solar panel values and best battery values​

Best values, IMO:

• alternator charging - constant-duty solenoid triggered by IGN
• panels - used 200-400w 20v/24v panels off craigslist, typically less than $0.40/watt
• controller - chinese mppt like Renogy, EpEver, etc
• battery - another set of 6v GC FLA if you are firmly against lithium.

Not going to try to convince you to reconsider Li, but here is my experience.

When my last GC bank was nearly EOL (after going ~10% cycles past mfg spec) I did the math on GC vs LFP. $ per lifetime kWh. For my use case breakeven was ~4.5 years. Since I plan to live in the van longer than that I bought 100Ah of lithium to replace my last 220Ah GC bank. Breakeven would have been ~3 years if I DIY'ed the lithium, but I couldn't wait for parts to come in from the mainland. Performance has been excellent.

In addition to the long-term $/kWh. Li allows me to camp in areas with sketchy solar without worrying about completing a lengthy Absorption. I also considered carbon-doped GC (like the T105RE) for uneven insolation. but when I did that math it looked like +16% more cycles under PSoC for +30% cost.