RV.Net Open Roads Forum: Tech Issues: this is why

RV Blog

  |  

RV Sales

  |  

Campgrounds

  |  

RV Parks

  |  

RV Club

  |  

RV Buyers Guide

  |  

Roadside Assistance

  |  

Extended Service Plan

  |  

RV Travel Assistance

  |  

RV Credit Card

  |  

RV Loans

Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Posting Help and Support  |  Contact  

Search:   Advanced Search

Search only in Tech Issues

Open Roads Forum  >  Tech Issues

 > this is why

Reply to Topic  |  Subscribe  |  Print Page  |  Post New Topic  | 
Page of 12  
Prev  |  Next
Sponsored By:
pianotuna

Regina, SK, Canada

Senior Member

Joined: 12/18/2004

View Profile


Offline
Posted: 12/29/21 11:39am Link  |  Quote  |  Print  |  Notify Moderator

SiO2 are much better than regular AGM, which are better than flooded. They have little or none of the monkey business needed for Li chemistries.

There is only one Li chemistry (Lithium Titinate) that would meet my weather needs (not wishes), but it is $1800 per 100 amp-hours, and many would be required because the recommended discharge rate is rather low. SiO2 can do 4C continuously.

Li are not well suited to cold except for the aforementioned above.

I fail to see how I could warm li batteries up to where they could be charged without using shore power, or a generator. Physical space will only allow 7 group 29 jars. Li are not that much smaller in dimension, and for MAXIMUM cycle life really only have 50% usable (40% to 90%).

Li do not love to be float charged. That means adding complications to the solar charging system for storage. SiO2 don't mind float at all.

I believe LI are a excellent battery for the middle of USA. Farther south things get a little complicated as LI apparently dislike high temperatures.


Regards, Don
My ride is a 28 foot Class C, 256 watts solar, 556 amp-hours of Telcom jars, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.

Itinerant1

Itinerant

Senior Member

Joined: 05/23/2017

View Profile



Posted: 12/29/21 12:21pm Link  |  Quote  |  Print  |  Notify Moderator

Pianotuna with all this talk of extreme cold living at times got me searching yesterday on YouTube videos and came across some... "frozen butt hang" surviving in a hammock in subzero weather on purpose just for fun doesn't sound like fun, almost like being in Canada at -40 in a Class C. More power to you...literally. [emoticon]


12v 500ah (5,120Wh usable), 20 cells_ 4s5p (GBS LFMP battery system). 8 CTI 160 watt panels (1,280 watts)2s4p,Panels mounted flat. Magnum PT100 SCC, Magnum 3012 hybrid inverter, ME-ARC 50. Installed 4/2016 been on 24/7/365, daily 35-45% DOD 2,000+ cycles.

3 tons

NV.

Senior Member

Joined: 03/13/2009

View Profile


Offline
Posted: 12/29/21 07:52pm Link  |  Quote  |  Print  |  Notify Moderator

pianotuna wrote:

Hi Folks,

This is why Li batteries are not a good fit for me.

https://weather.gc.ca/city/pages/sk-32_metric_e.html

-40 on Wednesday night.


Admittedly maybe it’s just me (??), but I see all this as just another (of many previous…) backdoor means of promoting SiO2 batteries..The weather is what the weather is, and as I see it ‘the weather’ is not the fault of LiFePo4 batteries, thus many times or incarnations must this same old weather rabbit-hole be reexamined??

3 tons

3 tons

NV.

Senior Member

Joined: 03/13/2009

View Profile


Offline
Posted: 12/29/21 08:06pm Link  |  Quote  |  Print  |  Notify Moderator

In any event, global warming should resolve this issue anyway in just a few more years - a soon to be moot subject??

3 tons

StirCrazy

Kamloops, BC, Canada

Senior Member

Joined: 07/16/2003

View Profile



Posted: 12/30/21 06:44am Link  |  Quote  |  Print  |  Notify Moderator

pianotuna wrote:

SiO2 are much better than regular AGM, which are better than flooded. They have little or none of the monkey business needed for Li chemistries.
yes they are much better than AGM, agm is the worst in my opinion and anything is better than that. they just fit a nich market of anti spill

pianotuna wrote:

There is only one Li chemistry (Lithium Titinate) that would meet my weather needs (not wishes), but it is $1800 per 100 amp-hours, and many would be required because the recommended discharge rate is rather low. SiO2 can do 4C continuously.


and how long are you going to discharge one battery at -40 at 1C? you arnt. you're getting 7 100AH batteries so now are you going to dischage them at 4C? nope I believe you will be under 1C as your trying to ballance the load over a period of time. at 0.5 C that would give you what a 350A draw ( thats more than a 3000watt inverter) and you will only have 420AH available to draw. . well if you bought 7 280AH LFP you would have @1C 1960amps availble on a constant draw, but you would also at -40 have a total of 1960AH availble because they are in the heated space and cold won't affect them. iven if you bought 100 amp battle borns and droped them into the same space you would have twice the amprage capability and capacity at that temp. I don't know why you insist on comparing irelavant numbers. if you looking at 7 batteries compare 7 batteries. oh ya the LFP even at 2.8 times the power size will be about 1/3 to 1/2 the weight and 1/2 the size so depending how your trays are set up you could probably fit more.

pianotuna wrote:

Li are not well suited to cold except for the aforementioned above.
well thats not entirly true, they use Li batteries in skidoos, and quads and they seam to work fine in the cold. but thats another issue and not as relivent in this situation. yes that is the one downfall you need to be above 0 for the battery to charge but it is easily acheavible

pianotuna wrote:

I fail to see how I could warm li batteries up to where they could be charged without using shore power, or a generator. Physical space will only allow 7 group 29 jars. Li are not that much smaller in dimension, and for MAXIMUM cycle life really only have 50% usable (40% to 90%).


three things here there are several ways to heat them up, two you mentioned the third is solar amd you only have to heat the little area where the batteries are but you won't mount them inside so its a mute point I don;t even know why your going on if your not willing to even discuss the ways to do it.

actualy they are about 1/3 to 1/2 the size. the comercial dropins are a lot of waisted space just to make the container the size to drop in. if you want to realize the space savings you have to get some one who puts 280AH in that same size container or build your own. for example a 280 ah home built is 6" x 8' x 11" add say 1/2" to the 6" demention for your BMS heck add a full inch lets live a little.

as for your 50% thats just bull mularky and you know it as we have showed you before. to get rated life of up to 4500 cycles it is 100% then at the end of the life they still have 80% of the original capacity and may live on that for another 20 years. there life is defined as when they hit 90% of there original capacity. if you use a 80% discharge that life can increase to about 7000 cycles depending on the manufacture and configuration. but if I start off with a 280 or 300AH battery, I think I saw 320AH cells the other day now , and lets say I totaly cycle it 40 weekends a year and its rating is only 3000 cycles well after 37.5 years I will only have 224 AH im ok with that. and studies show the first 20% drop is the fastest. its like the output curve of a LED they lose brightness fast to about 80% then they last forever at that level.


pianotuna wrote:

Li do not love to be float charged. That means adding complications to the solar charging system for storage. SiO2 don't mind float at all.


lets rephrase this again. they do not like to be stored at a float charge if your float it set right, for the average person it won't be an issue, the only issue it will add is turning off your batteries when you get home from camping like most people do.

like I said in the last post if they won't work for you because you won't reloacate them or insulate around them and put heaters on them thats fine, but don't claim SIO2 is a far more advanced battery as it isn't true. they are heavy bulky, more expensive than LFP now and have the same limitations of lead asid with a few failsafes built in.


2014 F350 6.7 Platinum
2016 Cougar 330RBK
1991 Slumberqueen WS100

FWC

The Wilderness

Senior Member

Joined: 09/12/2020

View Profile



Posted: 12/30/21 09:50am Link  |  Quote  |  Print  |  Notify Moderator

It is like a broken record around here.....

Let's do a quick apples to apples comparison between a $500 100Ah SiO2 Battery and a $500 100 Ah LiFePO4 battery..

The LiFePO4 battery is rated for 2500 cycles at 100% depth of discharge at 0.5C charge/discharge. Now go to the SiO2 spec sheet, in order to get 2500 cycle from the SiO2 the maximum depth of discharge is ~50%. So right there you have twice the 'usable capacity' from LiFePO4 relative to SiO2.

If you dig a little deeper (page 2 of the SiO2 spec sheet), the SiO2 only has a run time of ~60 minutes at 0.5C which would yield 50Ah. However, to meet the 2500 cycle lifetime, you don't want to go below 50% SOC, so that limits you to 25Ah from your 100Ah SiO2 battery.

Conclusion: LiFePO4 has 4x the 'usable capacity' SiO2 for the same lifespan for the same price.

The answer is about the same if you treat the SiO2 gently, let's limit the discharge to 0.1C and 50% DOD. In which case the SiO2 gives you ~2500 cycles, but still only yields 240 min run time to 50% DOD = 40Ah. In comparison at 50% DOD the LiFePO4 yields 13000 cycles - so 5x the 'usable lifetime'.

Conclusion: LiFePO4 has 5x the 'usable lifespan' of SiO2 under the same use scenario and price.

The thousands of dollars saved by using LiFePO4 over SiO2 would surely be plenty of money to pay for what ever upgrades are necessary to keep the LiFePO4 batteries warm.

pianotuna

Regina, SK, Canada

Senior Member

Joined: 12/18/2004

View Profile


Offline
Posted: 12/30/21 10:44am Link  |  Quote  |  Print  |  Notify Moderator

Li other than Lithium Titinate do not meet my needs. SiO2 do. It is that simple.

If I were to build a heated garage that would fit my RV then any old battery would do. Of course that's not possible as I live now in an apartment style condo. Somehow I think that would cost more than SiO2, too.

3 tons

NV.

Senior Member

Joined: 03/13/2009

View Profile


Offline
Posted: 12/30/21 11:07am Link  |  Quote  |  Print  |  Notify Moderator

Yep, in my view, another tireless, backdoor attempt at SiO2 marketing here…Yet for the overwhelming majority of user-consumers the SiO2 advantage is a low value, low utility ‘one trick pony’ belonging to a narrow old-tech market niche, not unlike the Radiola or infamous Stanley Steamer…JMHO

3 tons

NRALIFR

Let’s Go Girls! [End of Quote]

Senior Member

Joined: 11/27/2005

View Profile



Posted: 12/30/21 11:23am Link  |  Quote  |  Print  |  Notify Moderator

Sounds like for PieAnnerTooner, only EssEyeOhToo will do.

Got it. Don’t need to beat that into my head.

[emoticon][emoticon]

[emoticon] Let’s Go Girls! [emoticon] (End of quote)
NRA Benefactor Life Member
Lance 1121-Two Awnings, Slide topper, 3.6 kw Gen, Trimetric Batt. Monitor, 1500W Inverter, 40A Redarc DC-DC charger. 2016 F450 6.7 PSD.
[image]

valhalla360

No paticular place.

Senior Member

Joined: 08/19/2009

View Profile



Good Sam RV Club Member


Posted: 12/30/21 06:31pm Link  |  Quote  |  Print  |  Notify Moderator

StirCrazy wrote:


the ops case is extream, but not uncomon. I have taken a camper across country in -35 and it isnt fun.


It is both extreme and uncommon.

As a kid we used to go snowmobiling in northern Michigan...never saw anything close to -40C.

Vast majority of RVs get put to bed for the winter before the first flurries fly.

Even the OP admits, he has highly modified his RV for cold weather.


Tammy & Mike
Ford F250 V10
2021 Gray Wolf
Gemini Catamaran 34'
Full Time spliting time between boat and RV


Reply to Topic  |  Subscribe  |  Print Page  |  Post New Topic  | 
Page of 12  
Prev  |  Next

Open Roads Forum  >  Tech Issues

 > this is why
Search:   Advanced Search

Search only in Tech Issues


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:




© 2022 CWI, Inc. © 2022 Good Sam Enterprises, LLC. All Rights Reserved.