Batteries

I'd investigate the Lithium option, too... pricey, but long term savings and benefits now to then are impressive... some will disagree, but that's your option... freedom of choice

MEXICOWANDERER wrote:
Confusion

Using 100% of a 100 amp/hr battery is 100% consumed 0% left? Or am I missing something?

"Supposed to be" isn't an "is". This is why forums like this one actually ferret design potential from reality.

They claim you can get away with that many times with the SiO2, but recommend staying above 20% SOC (I do not plan to test going to dead flat with mine! :) )

Note that an Si bank does not have a BMS like Li does to help keep it from damage, but it seems you can go low and there is no too low, but there is a too high--so watch out for that if you go Si.

EDIT--note that they are adding some Si to Li to make better Li batts. Still moving the goal posts. Keep your money in your wallet--keep your powder dry unless desperate right now IMO!

Ok thanks all as I suspected it appears that we will be in for some new batteries shortly before any major travel any way. Have a short one week trip in the next few weeks at a park, but may try not to hook op to se how it goes. Will probably go with another lot of Crowns or Trojans if they will fit, I kind of shoehorned my Crowns in to my homemade battery box. If one drops dead I can always use the 2 best.

Confusion

Using 100% of a 100 amp/hr battery is 100% consumed 0% left? Or am I missing something?

"Supposed to be" isn't an "is". This is why forums like this one actually ferret design potential from reality.

Fyi,

The SiO2 group 27 battery is 100 amp-hours with 100% available. Cycle life to 0% state of charge is 620. Cycle life to 80% (20 amp-hours left) is 1500.

Trojan T105s in lead acid. Second set in 15 years. Wouldn't have to replace them except where we stored it they forgot to check the batteries before they closed up apparently for a few months. They were bone dry. They came back up but damage done.
We are having Deca maintenance free batteries installed in a few days and hopefully we won't be dealing with checking the batteries again. 13.5 is a good reading if setting stored an not connected.
We always stored ours connected to 50 amp but now we don't have enough voltage where we store, for now. The transformer won't work on 115. The batteries are turned off.
We never did discharge our batteries much if at all. and should have deep discharged them a few times.

You will get nowhere fast if you insist on "K-Mart quality" anything.

"My Yugo is superior to your Lada" irrelevance.

And BFL, your decision to outwait the hype with lithium is wise. There is a hell of a lot of difference between a management system that costs $5,000 and another that costs a twentieth as much. I did not rate my "Circumnavigation" charging systems as such until several made it in style. Four years later. And zero failures.

From The Forever Battery to STP The Racer's Edge, to race driver endorsements of chlorine motor oil additives (let's not forget frying pan Teflon) the avalanche of hoodoo has been almost overwhelming.

But comparing Sow's Ear Silk Purses is a waste of time. To suggest that Lifeline competes with used Chinese AGM batteries is not rational. Nor is paying more than a hundred dollars for a garbage grade group 34 battery.

Five years..time to watch closely and prepare to replace.

That is close to how we do things and also get about 5 years from four 6s.

They start to show signs like that (low SG in some cells, reduced capacity) but then instead of gradually declining, one day they "fall off a cliff". So if you are out somewhere and that happens so you have to return to get new batteries, and that is unacceptable, you have to get new ones before that trip for sure.

I tried 12v "deep cycle" AGMs (ie rated for "cycle" or "standby" use ) on the basis they are supposed to be better for the high draws with less voltage drop when using the big inverter, but the AGMs I had could not take the punishment it seems. They fell off a cliff after two years! :( So we are back to the trusty and much less expensive flooded 6s. (East Penn GC15s this time around)

IMO the new battery technologies Si and Li are too expensive to "try out" for that kind of work. Some folks have tried them, and are getting good results for their five years at it so far, but we haven't got results from how much longer those batteries can "keep on ticking" being driven hard like that.

So let them report how they do in their second five years at it, while we do another round of flooded 6s that will do that hard work for sure, and then see where things are at five years from now. :)

12.69 Resting sounds ..Hold on. Well the book says 12.9 is full up
But if there is any load on that battery it will take it down a bit.

Resting means you disconnect the negative lead.