Making the right call on batteries

[HamSkoolie]

Originally Posted by cadillackid

uhm i think you mis read me... I was agreeing with you about NOT using FLA batteries indoors.. thus why my batteries are AGM....

Nope, I read yours just fine. You just got in before my response without quote (my bad) to John61ct.


The below is not directed to anyone, just a statement.

I am simply amazed by the lack of concern over serious safety and financial risks that so many people seem to be willing to ignore. Perhaps it's a matter of inexperience and youth with a dose of higher risk tolerance versus decades of experience, more knowledge of the real world risks and lower risk tolerance having seen how painful big mistakes can be.
I went looking for instances of FLA batteries causing Hydrogen gas issues and it wasn't hard to find them (I've put links to two of them below). Full sized homes being exposed to unsafe (medically and fire/explosion hazards) levels of Hydrogen gas from charging FLA batteries in golf carts. One interesting case was an entire warehouse from a single forklift being charged. Compare the size of battery banks and cubic feet of space between a skoolie and a warehouse or full sized home. There IS an issue.



There is a reason the Underwriters Laboratories (and European counterparts) exist. I have seen insurance claims denied because a commercially manufactured electrical component wasn't UL listed. I'm not aware of ANY of those denials being reversed.

I personally know two skoolies who lost their bus after a DIRECT lightening strike fried their system. Their insurance claim was denied because their battery was DIY even though a UL certified battery is unlikely to survive a direct lightening strike.


Golf cart

firehouse.com/rescue/article/10518243/the-unexpected-golf-cart-hazard


Warehouse

fireengineering.com/health-safety/the-potential-danger-of-charging-lead-acid-batteries/

[john61ct]

Originally Posted by Rwnielsen

Just for clarification...FLA is flooded lead/acid is it not? A "car" battery?

Yes to the former but mostly no to the latter.

True deep cycle FLA are used in golf carts, fork lifts, floor polishers, lots of industrial uses.

And solar storage, campers' & boats House banks.

Large 2V cells are not uncommon, too heavy to lift manually.

Very few 12V batteries in the automotive BCI form factors are suitable for deep cycling, no matter what the label or other vendor marketing copy might say.

Same with AGM, also commonly used for automotive Starter / cranking purposes

[john61ct]

EV battery chemistries at 3.6 - 3.7Vpc are not safe enough for this use case.

Unlike LFP (3.2Vpc) or lead banks, very much at risk of thermal runaway, especially as they get older.

[john61ct]

Even for lead 6V or 12V units can be paralleled, but going past 2 or 3 you get uneven wear from imbalances in resistance

resulting in shorter lifespan overall, weakest link effect.

LFP drop-ins, verify with the maker what they recommend.

But as kazetsukai states, best to parallel at the 3.2V cell level, so if you want 300+ Ah at the bank level, use 3P x100Ah cells, or 2P x180Ah cells.

Then put those Groups in series to get to the voltage you want, 4S for 12Vnominal.

LTO is indeed another safe LI chemistry, very long lived and robust, but nominal voltage is much lower and less energy dense, so not used as often.

Yes noobs should just stick to lead to climb the learning curve, get experience.

Murdering an $800 bank is much less painful than one costing thousands

[kidharris]

Originally Posted by ladybird_bus

And 'no expert'? What is an expert but someone who has specialized in a subject deeply enough to know a great deal about it?

Now, lets apply some logic.

When I was 10yo, 1960, I learned that where the term expert came from was:


"X" is the term for the unknown and a "pert" is a drip of water: therefore, an expert is an "unknown drip".


Will Prowse is "known", therefore, he cannot be an expert.

[kidharris]

Originally Posted by dzl_

^^ At least the above is my current best understanding, my mind is a bit foggy on the details right now, its been a few months since I've thoguht about batteries/energy storage now and my mind has been on other things.

Have you been hanging out in the Walgreen's parking lot with jawild.

[kidharris]

Originally Posted by john61ct

Farts can be explosive in specific circumstances too, but it would simply be fear-mongering to claim they are dangerous.

The quantity of gasses released by FLA batteries is very very small.

The box being ventilated means they are dispersed / diluted so that they are no longer harmful.

Cooking a spicy dinner would cause more discomfort than even 800Ah bubbling away toward end of the CV cycle

but just the same if you felt discomfort, the solution is easy, just crack a window or turn on your vent fan.

If you are sensitive to the smell by all means vent to the outside

but preventing explosions is not the reason to do so.

turning on an electric vent fan to dump hydrogen gas doesn't sound like a good idea to me. Lighter than air gases like CO, H2, &/or CH4 (aka methane or farts) tend to ACCUMULATE at the ceiling, filling a room from the top downward, and cause what fire fighters call a backdraft, which is the explosion that people see in the movies when a house is burning and suddenly explodes. Once the gas level (mostly CO in a fire) drops low enough in a room to contact an ignition source and sufficient oxygen, kaboom. The gases CO, H2, and CH4 (from a fire) come from incomplete combustion as in gasification.

[john61ct]

I said nothing about electric fans

The quantities of vapor are miniscule

Any ventilation at all is sufficient to prevent any and all ill effects.

You would have to go to heroic purposeful efforts to seal up the box enough to cause a problem

so long as you do not do that, there will be no problem.

As stated if you detect a smell at the end of the charging cycle and want to eliminate it

then do so.

At that point you are still light years away from there being any other problem.

There are many instances where dilution is not the solution to pollution, but this is not one of them

[kidharris]

Originally Posted by john61ct

I said nothing about electric fans

When you said....


"but just the same if you felt discomfort, the solution is easy, just crack a window or turn on your vent fan."


ok, what kind of vent fan were you referring to?

Originally Posted by john61ct

The quantities of vapor are miniscule

I guess putting the word ACCUMULATES in all caps was not enough to get your attention


BTW, How many batteries charging at the same time does it take for the effects not to be "miniscule"?

Originally Posted by john61ct

Any ventilation at all is sufficient to prevent any and all ill effects.

You would have to go to heroic purposeful efforts to seal up the box enough to cause a problem

so long as you do not do that, there will be no problem.

Why do vented FLA batteries sometimes explode?


Also, you do realize that a lot of these Skoolie folk are going "to heroic purposeful efforts to seal up the box" with foam, caulk, and what ever else they can figure out, right?

Originally Posted by john61ct

As stated if you detect a smell at the end of the charging cycle and want to eliminate it

then do so.

So now we are supposed to smell our batteries every time they finish charging? Hydrogen gas has no odor and will accumulate at the ceiling anyway, and the other gas are not good to breathe. Once again, doesn't sound like a good plan.

Originally Posted by john61ct

At that point you are still light years away from there being any other problem.

fire, explosions, and suffocation are enough problems for me

Originally Posted by john61ct

There are many instances where dilution is not the solution to pollution, but this is not one of them

I get it now.

You consider flammable gas as pollution


Ok, I can see that you ......honestly, I don't see, but I am giving up. This is a waste of time and I believe that most people do not agree with you on this. Probably all those warning labels that we have read on our car battery chargers and batteries over the years. All the stories that we heard over the years probably didn't help either.


I am not a battery expert. I am following this and trying to learn, but this sounds like bs and I have seen nothing to back it up, but lots to disprove it over the years. Certainly not what I have come to expect from you.

[john61ct]

Ventilation means there is no accumulation.

I already listed above the reasons why lead batteries explode, and not just FLA.

The volume of a whole bus is ridiculous, absolutely no way. I was talking about a battery box that's all, just leave openings there.

A person getting bothered by the smell is the only reason to go to the trouble of sealing the locker and venting to the outside.

I am a very cautious person, listed all the necessary precautions

all this is just fear-mongering, not necessary in real life at all.

But certainly no harm in being over-cautious for those so inclined.

[kidharris]

Originally Posted by john61ct

Ventilation means there is no accumulation.

I already listed above the reasons why lead batteries explode, and not just FLA.

The volume of a whole bus is ridiculous, absolutely no way. I was talking about a battery box that's all, just leave openings there.

A person getting bothered by the smell is the only reason to go to the trouble of sealing the locker and venting to the outside.

I am a very cautious person, listed all the necessary precautions

all this is just fear-mongering, not necessary in real life at all.

But certainly no harm in being over-cautious for those so inclined.

nonsense...

[cadillackid]

the takeaway for me seeing that I dont live in, or camp, or off-grid, seems to be that AGM (or apparently Fake-AGM) batteries seem to work great for me in my Mobile Office Setup.. esp since I got a pile of them for free..


LFP sounds like what I would need if I wanted to have huge amounts of capacity for things like running A/C or cooking on electric cooktops.. the additional cost of LFP buys a *LOT* of diesel fuel or Genny gas for the few times I actually want A/C when not driving (during the day).. LFP also sounds much more complex and something probably not best charged by alternator..


FLA seems like the Best of lead for those wanting Large banks that they can get the deepest cycle out of...

[john61ct]

AGM is just one base battery type.

There is no "fake" problem with the AGM label.

The issue is sellers fraudulently using the label "deep cycling" on AGMs that are really just Starter units.

Odyssey, Northstar and Lifeline are the quality AGM makers whose statements are worth trusting.

Using those will at least get good longevity if cared for properly, just not as long as comparable FLA, and at a higher price.

And their "cared for properly" requirements are fussier, require better equipment calibrated more precisely.

The facts that lead for longevity

needs to be recharged most cycles all the way back up to 100% as per trailing amps, combined with that requiring at least 7hrs even with high amps available

and should only be discharged on average 40-50%

are the main disadvantages compared to quality LFP.

Simplicity and familiarity on the other hand, along with much lower up-front cost, very much favour sticking with lead.

[HamSkoolie]

Originally Posted by cadillackid

the additional cost of LFP buys a *LOT* of diesel fuel or Genny gas for the few times I actually want A/C when not driving (during the day).. LFP also sounds much more complex and something probably not best charged by alternator...

Lithium batteries are actually cheaper than the alternatives, even than FLA golf cart batteries. The initial cost is indeed higher for lithium chemistry but

Several factors aren't captured in simple cost comparisons.
Lithium allows far deeper discharge thus smaller kWh ratings for the bank so smaller banks are required.
Lithium is substantially lighter which, though small, contributes to greater fuel economy and less strain on the drive train and suspension.
Lithium provides substantially more charge cycles.
Lithium can be charged faster thus allowing full use of large solar arrays
FLA chemistry allows a lower up front cost but requires substantially more maintenance in the form of watering, corrosion control, etc.
FLA weighs substantially more, require more substantial tray/racking systems, more interconnecting bars or cables, and substantially more space which is a major concern when building any mobile platform.

While there are hazards associated with any battery technology, FLA batteries produce toxic and explosive gasses in their NORMAL operation.
We are planning a 10kWh battery bank and have access to 210ah 6vdc (used but serviceable) golf cart batteries for $80 including core charge. 12 of those batteries would provide 7.6kWh at 50% depth of discharge. Total cost for JUST the batteries (still need trays, cables, etc) would be $960 and weigh (batteries alone) 720 pounds.
We have chosen to go with Lithium technology batteries designed to be mounted in server racks. They are available in 12, 24, 36, and 48 volt versions but all have the same kWh rating of 5.12 and weigh an amazing 106 pounds each.
Two of these batteries provide 7.7kWh at 80% depth of discharge. Total cost for the two batteries is $3000 plus much less cable and tray/rack requirements and weigh (batteries only), just 212 pounds.
The REAL kicker though is that those used golf cart batteries will go maybe three years at 50% DOD while the lithium will go 7000 cycles (that's NINETEEN YEARS).

The Lithium bank will cost $158 a year
The FLA bank will cost $320 a year
Even if you can squeek out 5 years from an FLA bank (not likely) $192/yr


Lithium technology is cheaper and superior on all fronts except up front cost.
As for charging Lithium with an alternator, there are devices specifically designed for doing so and proper system design can create a main, secondary, or just backup system of charging a Lithium bank.

[john61ct]

Proper quality LFP cells from a known good maker in North America

acquisition cost is at least 7x even AGM cost per usable Ah

not counting the extra infrastructure costs like battery monitor, special charge sources, BMS, dummy loads etc.

Much more so comparing FLA like Duracell GCs at ~$1/Ah.

So given a very conservative 5year lifespan before hitting 70% SoC

you will not start to see ROI until at least 35yrs.

I personally am confident that **I** will reach that lifespan

but doubt the average noob would. All it takes is one slip of carelessness, one "unforeseen event" and that investment of thousand$ can be rendered scrap.


If the greater density or other technical advantages are worth the extra investment / higher learning curve

or if you enjoy being on the leading edge technically as an interesting hobby, or see them as a status symbol, then sure go for it!

But no, from purely economic grounds LFP does not make sense.

[HamSkoolie]

And here I thought we were in the 21st century.
My quad copter is under 250 grams, has a 2.7k camera on a 3 axis gimbal, flys for THIRTY MINUTES on a battery, can go out well over 10 miles (and back) hover autonomously, return to "home" or to a new position autonomously, and much more. Comes with three batteries for a 1.5 hour flying day, controller and charger included. ALL for TWO reasons. Chinese production and lithium technology.....of the 21st century.

The 10.24kWh lithium system we're going with has built in BMS, data ports, and circuit breaker, and temperature protection. Each of the 5.12kWh units fits in a 19.5" rack and is about 6" high. They're quality, inside and out and they're Chinese production lithium technology.
It's not about anything more than installing a system capable of accomplishing the mission of running air conditioning 24/7 without reliance upon shore or genset power.
When we go to sell our rig, it will still have well over 10 years life left in the batteries and by then, who knows what awesome storage means will be common place. In the mean time, we can all but forget about our electrical system and just make a periodical condition and appearance inspection.

[kazetsukai]

Originally Posted by HamSkoolie

Lithium batteries are actually cheaper than the alternatives, even than FLA golf cart batteries. The initial cost is indeed higher for lithium chemistry but

The upfront cost per Wh used to be extremely competitive as well, when I bought mine it was dirt cheap, neck and neck with lead.

Prices have gone up, last I checked 150%+. Not exclusive to lithium or anything...

Originally Posted by HamSkoolie

We have chosen to go with Lithium technology batteries designed to be mounted in server racks. They are available in 12, 24, 36, and 48 volt versions but all have the same kWh rating of 5.12 and weigh an amazing 106 pounds each.
Two of these batteries provide 7.7kWh at 80% depth of discharge. Total cost for the two batteries is $3000 plus much less cable and tray/rack requirements and weigh (batteries only), just 212 pounds.

BMS? Wiring them in series? What bank voltage are you going for?

Originally Posted by HamSkoolie

The REAL kicker though is that those used golf cart batteries will go maybe three years at 50% DOD while the lithium will go 7000 cycles (that's NINETEEN YEARS).

I haven't heard of any LFP that will do 7000 full cycles. At most 5000 with 80% usable SoC. 7000 with 50% usable SoC or outright failure maybe. I would just be more conservative in my cost estimates than by using that number.

Originally Posted by HamSkoolie

Lithium technology is cheaper and superior on all fronts except up front cost.

Far from it... I wouldn't use lithium outdoors or in harsh environments. Just because lithium is overwhelmingly better for your/my use case doesn't mean its all around superior....

Originally Posted by HamSkoolie

As for charging Lithium with an alternator, there are devices specifically designed for doing so and proper system design can create a main, secondary, or just backup system of charging a Lithium bank.

Here's an example, really. You need an extra moderating device to prevent your alternator from blowing up charging it... yes, this is due to assumptions about batteries made when designing those alternators, but ideal never beats reality in a slug fight.

Originally Posted by john61ct

Proper quality LFP cells from a known good maker in North America

acquisition cost is at least 7x even AGM cost per usable Ah

Not comparing apples to apples at all here. You are comparing the most expensive lithium vendors to some of the least expensive AGM vendors, this is why you are absurdly off base here.

Look, even today you can find crappy "3000mAh" chinese 18650s out there that will barely deliver 500mAh. But your take on the quality of (in particular) Chinese LFP is in error. Some vendors are _swindlers_. You think there aren't American swindlers out there, or "American" companies that aren't just reselling repackaged Chinese-sourced LFP? What you look for is reputation, and some Chinese suppliers have it. Lots of people have tested some of these cells (myself included) and they deliver. You can speculate on their lifespan all you want, but the same arguments apply to any option you've presented. At present the best I think one can do is look hard at the spec sheet.

Originally Posted by john61ct

you will not start to see ROI until at least 35yrs.

What is/how are you measuring ROI? You can't even come up with a number of 35 years if operational lifespan is only 10, at that point there isn't an ROI number at all. Lets be perfectly clear here- if your plan is to make money, or to consume less money overall using a battery bank versus lets say, the grid, you're not going to win with any battery technology until well past its lifespan. People wanting to do that should just grid-tie with tons of panels, forgo any battery bank whatsoever.

People who want functionality (rather than cost savings) on the other hand, the point of "return" is the moment you don't have to plug in to get power. The return is the independence from the grid... The cheapest place to get power is always going to be where power is mass produced.

Originally Posted by john61ct

but doubt the average noob would. All it takes is one slip of carelessness, one "unforeseen event" and that investment of thousand$ can be rendered scrap.

I mean, one close proximity lightning strike later your FLA bank could be fried too...

Somehow virtually every cell phone, camera, laptop, etc all get battery management right for Mr Joe but a BMS cannot?

Originally Posted by john61ct

or if you enjoy being on the leading edge technically as an interesting hobby, or see them as a status symbol, then sure go for it!

Why must we mind read and bring motives (perverse or otherwise) into the discussion...

[dzl_]

@hamskoolie


Some of the things you've said--specifically the 7000 cycles bit--make me think its possible you are considering buying from or have bought from a fraudulent company I am aware of, that makes that cycle claim (and also presents themselves as a manufacturer when they are just a flipper of grey market, and B grade cells and assembler of packs). If you don't want to share the name of the supplier here (I believe people have already asked) definitely do your due diligence, there is a lot of misrepresentation in the direct from china lifepo4 retail space, and a good bit of outright fraud.



Exagerrated claims are the norm unfortunately and not necessarily indicative of outright fraud but be careful. Try to get a manufacturer datasheet for the cells they use, this is going to be more trustworthy and more objective than anything the seller tells you or states on their website/sales page, unless its a well known trusted seller.



And as Kazetsukai has said, use more conservative estimates (for the cells, but really its a general good rule of thumb) than the marketing numbers (even if they are presented as tech numbers). I am not aware of any large LFP manufacturer that claims over 5000 cycle life in their technical documentation, most state a number between 2000-4000 @ 100% DoD, this is factory testing YMMV.

[Mountain Gnome]

I was told as a kid that 1000s (or was it 10,000s) of FLA batteries explode under the hood of a car every year and injure someone, from vented hydrogen gas. (and at the time, DieHard batts exploded the least, but I think they are just "generic" batts with a "brand name" now) No "accumulation" needed.


Look at a new pair of jumper cables. What do the instructions say? The last step in connecting them is to connect the ground to the MOTOR block, not the battery. Why? Because the spark may ignite the H2 gas. Hood raised. Open sky above. Still, it can explode and impregnate your eyeballs with debris, blow out your eardrums, throw you to the ground, cover you with acid, and maybe catch you and the car on fire.


You don't need to fan-vent your indoor FLAs. Just keep them vented at the top of a sort-of sealed box. The H2 gas is the lightest gas of all, and it will quickly find its way out the box top-vent and up to outer space. But any spark on the way will ignite it.

Hydrogen gas forms explosive mixtures with air in concentrations from 4–74%

-Wikipedia


Don't know about the Sulphur-Dioxide gas that is vented, is it heavier than regular air? If yes, then vent it at the bottom , also.

[john61ct]

As I very clearly stated here,

https://www.skoolie.net/forums/f49/making-the-right-call-on-batteries-37696-post456666.html

people continuing to use their batteries past the EoL point does make them dangerous.

And yes stupid people abusing Starter units under the hood

are a completely different situation from sharing your living space with a deep cycling bank weighing hundreds of pounds.

Just as true for AGM, GEL, all lead chemistries

Don't be stupid is all, pay attention, regularly cap test your batteries and proactively replace them long before gross symptoms of wear appear.