li fe po4 battery upgrade?

gmctoyman wrote:
How much .. Facebook stock did you buy at IPO?

Some. Very close to ipo price, but I felt sorry for those who did at its offering because it didn't do so well for the first few months.

Anyway, given that, I feel confident in my Li upgrade. :)

We have three years experience with a 9 kW-hr LFP (48V nominal) in 34' 5th wheel and one year experience with 4.5 kW-hr LFP (12 V nominal) in Roadtrek). We primarly boondock and generally do not plug in for the few instances when power was available.

Just spent 14 weeks in Labrador/Newfoundland and then another 14 weeks in Mexico (Yucatán, Chiapas l, Morelia, and West Coast) and did not plug in the last five weeks. This was done in Roadtrek since there are places you cannot take a fifth wheel - and if you do, you may not get back out). 5th wheel was left at son's place at 7500' in northern NM where temperatures got down to -20 F but battery suite was disconnected. The Roadtrek battery suite is 125 pounds and would require almost 500 pounds for equivalent lead acid battery suit

Cris at Technomadia was quite candid about heat damage to his LFP bank. Their bus was in for repair in Arizona in summer and was sitting on asphalt. The battery bank and inverter were in the same non-vented compartment where the temperature could easily be excess of 130 F. They made mistakes as the pioneers in LFP for RVs. We have paid attention to their mistakes as well as to their innovations

Our battery bank and 4kW PSWI of 5th wheel are in front bay where three panels can be opened for cross ventilation and is in shade of front overhang. Put our outside remote thermometer in front bay on summer days and have never had temperature above ambient with panels open. We do have two 12 V outlets for fans if it were to get hotter. Also have 110 V outlets for light bulbs to heat compartment were it to get to cold.

The battery bank and 2.5 kW PSWI in Roadtrek are below bed. Son put in fan and thermostat to draw air from cabin to cool battery bank and PSWI above about 95 F.
Reed and Elaine

mapguy wrote:

MEXICOWANDERER wrote:
I spent $28 to get an interactive miniature computer energy management meter that has a pair of terminals capable on controlling the coil to 1000 ma of a relay. Choose high or low voltage disconnect. Reasonably accurate to .005 + or - Thing makes a Samsung S8 menu look like a Dick & Jane primer.

don't tease - how about a link?

The moon is right, the vampires have risen, I have modem connectivity today...

http://www.ebay.com/itm/172281588037?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I personally don't see Lifepo4 batts becoming mainstream for RV's in the foreseeable future. I was involved in field testing them for the military a couple times in recent years and they did considerably worse than we anticipated based on accelerated lab testing. The cumulative effects of temperature, sitting idle fully charged etc. we encountered in real use had a considerably more of a negative affect on life than the manufacturer data had us expecting.

You'll want to make sure your BMS takes care of shutting things down during discharge when any single cell drops too low, build in protections to prevent charging when too cold, or too hot, and I personally wouldn't take the battery into the top 10 percent of it's capacity either keeping it between 90 percent and 20 percent. If possible it would be good to have a method for dumping the charge down to about 40 percent if it's going to be sitting idle for more than a couple days, especially in hot weather.

Finally, keep in mind that personal observation compared to measured data can be significantly different with new technology. People tend to see what they expect to see. It's also wise to compare apples to apples. Those using batteries in a marine environment, or maybe aircraft environment face significantly different conditions temperature extreme wise than what you might encounter in a land based RV. Finding data for use in situations closely resembling what you may encounter can be difficult give the relatively small amount of information currently available.

COST BENEFIT RATIO

RISK BENEFIT RATIO

Pass the Grey Poupon is beyond my means. Monitoring and managing each individual cell is an eyebrow raiser. The cold weather chilly-willies and overdischarge destruction not only tips the scale - it tips over the table.

Owner evaluation may well be the same as the NO BAD DAYS tee shirt philosophy. But I'm old fashioned. If I wanted venison I would not reach for a bow & arrow.

Age. I guess...

pianotuna wrote:
brulaz,

Just like you I'm interested in the Firefly Carbon Foam batteries. Has anyone seen reviews of them from end users?

https://www.emarineinc.com/Firefly-Oasis-12V-Group-31-Battery?gclid=Cj0KEQjwt6fHBRDtm9O8xPPHq4gBEiQAdxotvABAbYJ3pt34_bh2rk7sFnsfcwhLm3tYoKDTupaltzwaAjpF8P8HAQ

The only issue is weight with the Firefly. All the other problems disappear.

Here's a marine review:
http://www.trawlerforum.com/forums/s3/carbon-foam-batteries-1-year-later-26233.html

And Bruce Schwab deals with and evaluates carbon foam and LiPO4 here:
https://www.bruceschwab.com/advanced-energy-storage-systems/

I see he's also selling a "OPE-Li3 ND-DC" battery management system for LiPO4.

None of this stuff is cheap. These people are driving boats worth hundreds of thousands of $$$, so be forewarned.

mapguy wrote:

...
Thanks for posting the diagram. Please note that the CleanPowerAuto battery management products are no longer available to purchase.

Any chance you can provide a link to the diagram source?

That's a shame. Their stuff was affordable and apparently worked well in the marine environment.

Pretty sure that diagram was in one of the long discussions in the cruisersforum, perhaps this one:
http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069.html

Here's another source of info from a marine prespective:
http://www.pbase.com/mainecruising/lifepo4_on_boats

Good Luck!

Happily I fosee no nightmares

brulaz wrote:
But, sadly, all I see in my future are FLA GC2s.

:(

brulaz wrote:
Speaking about contactors ...

When looking at LiFePO4 I ran across this diagram on a marine forum for an outrageous boat system using CleanPowerAuto's HousePower and MiniBMS battery management systems.


It has two solar, an alternator and an AC chargers. And about 6 contactors. It was entertaining to sort through how it worked.

If it weren't for the freezing temperature issues, would prolly still be toying with the idea of LiFePO4. But now am more interested in dreaming about a future set of Firefly Carbon Foam batteries ... :)

But, sadly, all I see in my future are FLA GC2s.

Thanks for posting the diagram. Please note that the CleanPowerAuto battery management products are no longer available to purchase.

Any chance you can provide a link to the diagram source?