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Time to upgrade the batteries


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Currently we have 4 6-volt FLA batteries and plan to upgrade soon to LIFEPO4 and have a few questions. 

1) My EPEVER MPPT solar controller has a low temperature cutout in the programing.  Will that be sufficient to prevent low temperature charging?  Most of the batteries I am looking at have integral BMS some of which do not provide for this condition.  As a general rule when it is too cold to use our blueflame heater due to the moisture it adds we run the furnace, and it keeps the inner basement and battery storage area from freezing.  (Found out the hard way that you could freeze up driving down the road and now when very cold just leave the furnace on when traveling.)

2) How best to deal with storing our rig with LIFEPO4 batteries during cold temperatures?  Easy enough to shut down the inverter/charger and solar MPPT controller.  Will stopping the charging suffice or do I need to plan on supplemental heat?

3)  Has anyone have any experience with 'Global Power' LIFEPO4 batteries?  There was a thread on the diysolarforum.com where the below link was posted.  The ad says these batteries BMS does have a low temperature cutout.  This eBay seller has %100 positive feedback BTW.  https://www.ebay.com/itm/373490407212

At $342.95 each with free shipping for 100 AH 12-volt batteries I am seriously considering pulling the trigger on 4 but would love to hear comments on my questions.

Relatively new to solar so thanks in advance for your thoughts.

Later,

J

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As you stated the problem with LFP batteries is charging below freezing will destroy them.  The batteries will still provide power in freezing temps.  For storage most just disconnect the batteries.  These batteries store best when not fully charged or completely discharged and the self discharge is low.  I keep my batteries around 50% in storage which for a 12v battery is around 13.1v.  I am not familiar with the batteries you are looking at but be aware that charging below freezing can quickly degrade or destroy a LFP battery.  My batteries are self assembled and have a BMS that stops charging below freezing.

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Just some additional information to consider:

1.  Will Prowse has a video on these batteries, I see in this text they might not have the low-temp cutoff:  https://www.youtube.com/watch?v=EpLl6ywpQPo

 

2.  You indicate "storage".  Not sure if that's "at the house" under your watchful eye, or if you're thinking of off-site storage of the rig.  If so, you might consider taking the batteries home!  A lot of theft goes on in those places.

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Jack FWIW I would NEVER rely solely on any solar charge controller or Converter/Charger settings or claims to NOT charge below freezing temperatures but further rely on a quality tested and approved BMS to do so. 

 A person could relatively easy and inexpensive as a backup wire his Converter/Charger using a thermostat so its inoperative below freezing, but I would still want a BMS that does the same for protection just in case

 Its NOT using them at low temps is harmful, but just DONT CHARGE THEM (either via BMS or Thermostats or supplemental heaters or controller/charger controls)   I still like a good BMS even with other protection methods...but thats just me 

 Your four 6 volt FLA's probably have a combined energy storage rating of around 400 Amp Hours of which 50% or 200 is useable HOWEVER if you install four 100 AH Lithiums in parallel, thats 400 AH of which at least (subject to BMS and personal preference, settings and choices) around 80% or 90% or more (320/360 AH) is available PLUS they charge faster and dont experience so much voltage sag/drop under load

 For long term unsupervised storage just make sure THEY WILL NOT RECEIVE ANY CHARGING (Solar or Converter/Charger) below freezing temps. Plus SUBJECT TO BATTERIES AND BMS if they discharge fully they may need to be excited prior to accepting charge 

 Make sure BOTH your solar charge controller and Converter/Charger are suitable for charging Lithium

While IMHO Battleborn have the best marketing and advertising and are great quality, there are several players out there now plus more coming onboard  SO SHOP AND READ REVIEWS AND CHECK OUT DIY SOALR WITH WILL PROWSE. After a ton of research I went with a different brand (NOT BB) and am 100% satisfied just make sure the BMS has all the needed features and protections. Some brands now have internal heaters to insure they aren't charged below freezing, thats yet one other consideration and means of protection   

 John T  NOT any solar expert so see what they have to say

 

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Thank you Randy, Darryl & Rita, Will and John for taking your time to pass on your experience.  Decided to take all of you suggestions. 

Hope to place an order for 3 100 AH batteries from Amazon that include a low temperature cut off 'tested' by Will Prowse. 

Will's video.

Amazon ad (Inflation now a $100 more)

https://www.amazon.com/LiFePO4-Lithium-Battery-Overland-Applications/dp/B09F2LLMY3/ref=sr_1_3?crid=1LA7B9GVDGQMO&keywords=lifepo4%2Bbattery%2B100ah&qid=1643130374&sprefix=lifepo4%2Bbattery%2B100ah%2Caps%2C608&sr=8-3&th=1

Later,

J

 

PS Can I add another battery in the (hopefully near) future or will that possibly/likely degrade the bank?

 

PSS First PS question now a hot item.  Apparently Amazon only has 2 of the batteries in stock (siting in my cart).  Bring up mixing not just different runs but possibly manufactures.  Still researching but thought I ask.

Edited by KodiakJack
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6 hours ago, KodiakJack said:

Thank you Randy, Darryl & Rita, Will and John for taking your time to pass on your experience.  Decided to take all of you suggestions. 

Hope to place an order for 3 100 AH batteries from Amazon that include a low temperature cut off 'tested' by Will Prowse. 

Will's video.

Amazon ad (Inflation now a $100 more)

https://www.amazon.com/LiFePO4-Lithium-Battery-Overland-Applications/dp/B09F2LLMY3/ref=sr_1_3?crid=1LA7B9GVDGQMO&keywords=lifepo4%2Bbattery%2B100ah&qid=1643130374&sprefix=lifepo4%2Bbattery%2B100ah%2Caps%2C608&sr=8-3&th=1

Later,

J

 

PS Can I add another battery in the (hopefully near) future or will that possibly/likely degrade the bank?

 

PSS First PS question now a hot item.  Apparently Amazon only has 2 of the batteries in stock (siting in my cart).  Bring up mixing not just different runs but possibly manufactures.  Still researching but thought I ask.

There are conflicting messages about adding parallel LFP batteries even from different manufactures.  From what I have read I believe it will work especially with the light draws typically seen in RV and solar. It is a fact that these batteries connected in parallel will self balance by voltage.To that end I have ordered some new cells to assemble a battery addition to our 5er.  These new cells are different size and manufacturer than the existing batteries but won't be here for another month (slow boat from China).  I will report back how well it works.  This will bring our batteries to 1400ah @ 12v. 

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1 hour ago, hemsteadc said:

It remains to be seen if a $300 LifePo performs as well and lasts as long as a $900 one.

That is a good question but virtually all of the cells I have seen are rated 3,000 to 5,000 cycles before the capacity drops to 80%.  A cycle is defined as fully charged to fully discharged. It is also believed that partial cycles can be added up to make a complete cycle.  Such as 50% plus 50% cycles equal one full cycle.  In any case 3,000 cycles @ 1 every day is a lot of years!  And 80% is still useful.  The BMS is another point that could fail but being solid state unless abused one would think it would last.  These cells have been around for years now and while there are some failures it is rare so I think it is worth the risk.  The $900 battery such as Battle Born does have the warranty though.

Edited by Randyretired
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Anyone paying $900 dollar for a Battle Born battery hasn’t checked pricing in a while.  Even buying them direct from BB their retail price is now $799.  If you know where to shop you can get them a bit cheaper than that.  They are still on the upper end of the Lithium battery price scale, but they are nowhere near the highest priced ones on the market.  They do have one of the best warranties in the business and their technical support is second to no other I have found and you don’t have to be a dealer or retailer to get that support.  In my opinion they are a great option, but they are by no means the only option.  There are many out their and some are better than others.

As to the OP’s question about adding batteries at a later time, that is not nearly as big of an issue with lithium as it is with other chemistry batteries. Usually if you do it within a year, you will be fine.  I would be careful mixing different brands though.  You need to pay attention to charge parameters and other settings.  Some manufacturers parameters vary quite a bit and using one manufacturers settings on another’s batteries could result in under or over charging possibly.

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19 hours ago, KodiakJack said:

PS Can I add another battery in the (hopefully near) future or will that possibly/likely degrade the bank?

Jack, great question, FWIW here's my answer:

"Generally" speaking YES you can add batteries in parallel of the same type/voltage/chemistry without degrading the bank. In parallel of same voltage batteries (voltage will be made/balanced the same) the Amps and Amp Hours is additive

 HOWEVER Its my advice and preference they be the SAME brand type chemistry voltage and even near age. I have seen different brands with different charging parameters, different max charge, and different max load ratings PLUS perhaps different BMS control and safety parameters. If I had say Amazon or SOK or Battleborns and wanted to add another battery I WOULD ADD AN IDENTICAL UNIT EVEN THOUGH SURE IT CAN STILL WORK EVEN IF NOT IDEAL 

 When connecting multiple batteries I advise and prefer that EACH receives the same charging current/voltage and delivers the same load current. Check out   http://www.smartgauge.co.uk/batt_con.html NOTE these are NOT my research or words no warranty do as you please

Its my opinion BB has the best marketing advertising and PR and I believe they are good quality HOWEVER there are more and more players coming online and some can use the same brand of cells SO DO YOUR OWN RESEARCH and check out DIY Solar on You Tube with Will Prowse. Its critical they have a good quality BMS with all the necessary protections

John T   NOT a solar expert so see what they have to say

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Thanks again all for your helpful comments.  They reinforce the research I have completed to date regarding adding batteries at a later time. I have found no more of the Weize batteries (referenced above) available, hence the only 2 I found are still in my Amazon cart.  It is very important to an Alaskan that each battery's BMS include a low temperature cut off.   So I continue to research LiFePO4 batteries with this feature, and in the mid price range. 

I have also found batteries that heat themselves and wonder how that would work over an extended period.   Would that draw them down too much?  I could leave the solar up, but not sure if that is a good idea without supervision.   Also found 12-volt heating pads, but the same questions come to mind.

Freezing up driving down the road is no longer an issue if I simply run the furnace while traveling, which would keep the batteries warm.  I am more concerned with storing without electric available in cold weather.  Winterizing both boats and RV's is second nature, and I have accomplished many times over the years.  Charging batteries and disconnecting them was usually the only requirement to get them through the winter when a trickle charge could not be used. 

The current state of our 7-year old 6-volt GC batteries are less than good but not yet totaled, certainly no longer 460 ah with more than one bulging.  I once found exposed plates.  Our Magnum inverter tripped on low voltage the other night for the first time.  So new batteries have moved up the to list and are to blame for my many questions.

Later,

J

 

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2 hours ago, KodiakJack said:

I have also found batteries that heat themselves and wonder how that would work over an extended period.   Would that draw them down too much?  I could leave the solar up, but not sure if that is a good idea without supervision.   Also found 12-volt heating pads, but the same questions come to mind.

Indeed if the batteries are used to power up resistive heaters (internal or external pads etc) they will finally run out of energy and the time required depends on 1) How much energy is stored 2 ) The temperature  3) The heaters load..........

How well active solar might keep up with the heater demands depends on how many solar watts, the intensity and angle of the sun and how many available sunlight hours and other factors etc. etc.

The decision to let solar charging system run unsupervised IS UP TO YOU. I wouldn't be a huge fan of such for extended periods even though sure it can work  

I believe ??? the self discharge rate of Lithium is less then FLA ??? so if they are fully charged when you put her to rest AND THERE ARE NO LOADS APPLIED (like heaters) and they cant be charged when its cold, and they have a good BMS HECK YOU MAY GET BY FINE its just impossible to say with so many unknowns. If there's no chance of and you dont intend to try and charge when cold or let solar run unsupervised, YOU DONT NEED BATTERY HEATERS RIGHT ????

 All being said if they are full charged with NO LOADS and a good BMS so they cant be charged when cold, even without solar left running,  I wouldnt be too afraid to give it a go for a few months BUT THATS UP TO YOU   

Wise choice to use matched batteries 

Again Im NOT any expert so see what they have to say

John T

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Many just disconnect the LFP batteries.  The self discharge is very low and these should be fine all winter.  These batteries are best stored about 50% SOC.  Heaters would of course use power and need charging to keep up.  If you are relying on solar it would need to keep up and if you get snow that could be a problem. If you want to heat the batteries for travel to allow charging some use tank heaters under the batteries.  Many of these already have a thermostat.  You could add a switch to turn it off when not needed.  That way you could heat for travel and disconnect for winter.

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I hope this question isn't too far off topic.

My batteries are still on the tongue of my trailer. 
With the cost of batteries upward of $500 each, I'd like them to stay on the tongue until I decide to remove them.

What, if anything, are folks doing to secure their batteries that are NOT INSIDE the rigs??

I've seen a couple of brackets on Amazon, and I could probably convince a local fabricator to make one like it, but I wanted to get a sense from the folks closer to the need for the theft protection what they are doing.


FB

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Jackpot.  DIYsolarforum has a number of informational threads on storing/using/charging LiFePO4 batteries in cold temperatures.  Would not say there is consensus on this topic, with one fellow even charging at -17 degrees and videoing it, along with recommendations to store at various states of charge, but for the most part, these batteries have proven to store just fine in the cold. 

A fellow I used to work with would say the self-heating charging batteries/mats cycle both John and I described would be considered "a self-eating watermelon" (Cape Canaveral term)...ha ha.  No longer a worry.  I think Randy has got it, just disconnect them and all will be good. 

Thanks all for you help.  If was fun getting smarter.

Later,

J

PS Moral of the story; buy 3 batteries now (with low temp cutouts) and add another of like type and manufacture (hopefully) as soon as possible.

 

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10 hours ago, franco-bolli said:

I hope this question isn't too far off topic.

My batteries are still on the tongue of my trailer. 
With the cost of batteries upward of $500 each, I'd like them to stay on the tongue until I decide to remove them.

What, if anything, are folks doing to secure their batteries that are NOT INSIDE the rigs??

I've seen a couple of brackets on Amazon, and I could probably convince a local fabricator to make one like it, but I wanted to get a sense from the folks closer to the need for the theft protection what they are doing.


FB

A lot of us have our batteries in storage compartments or inside.  I would  protect them some way.

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23 hours ago, KodiakJack said:

just disconnect them and all will be good

Good choice, Id say with absolutely NO loads like heaters etc., and no unattended solar or other means to accidentally charge if it's too cold, and a good quality BMS there shouldn't any problems. The worst might be if they ever discharged so low the BMS cut them off (which I doubt would even happen) and/or they (subject to design and BMS) need to be excited recharged but there should be NO damage

23 hours ago, KodiakJack said:

PS Moral of the story; buy 3 batteries now (with low temp cutouts) and add another of like type and manufacture (hopefully) as soon as possible

   Another good choice in my opinion

 Over 50 years of RV I started with RV/Marine,,,,,,then FLA 6 Volt Golf Cart batteries,,,,,,,then AGM,,,,,,,Now LiFePo4 and IM NEVER LOOKING BACK However in a few years they may be outdated lol

 John T

Edited by oldjohnt
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13 hours ago, pjstough said:

Do you really need low temperature cut off?

Absent all the specs and data, I can't sitting here provide any perfect answer for ALL brands, I can ONLY say the brands I'm familiar with DO NOT recommend (and BMS even prevents) charging in cold temperatures.

BOTTOM LINE charge at cold temps at YOUR own risk, but FWIW I'm not doing it myself just to be on the safe side

To each their own methods and risks 

John T  NOT a Solar system expert so listen to them PLUS AND ESPECIALLY the battery manufacturers

 

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I ordered 4 100 Ah LFP batteries with low temperature cut outs yesterday.  Yes a substantial increase in available Ah which should augment well with our on board solar, especially when I add additional panels.  We should end up north of a 1100 watts,  and I hope the batteries will charge while traveling down the road.  Speaking of which, having repaired a good bunch of pipe, fittings, and replacing our destroyed water pump from a freeze-up doing just this, I rather be safe than sorry.  Between the batteries BMS, the MTTP limit and the furnace running when it gets darn cold we should be just fine.  Thank all for your help.

Later,

J

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2 hours ago, KodiakJack said:

I ordered 4 100 Ah LFP batteries with low temperature cut outs yesterday.  Yes a substantial increase in available Ah which should augment well with our on board solar, especially when I add additional panels.  We should end up north of a 1100 watts,  and I hope the batteries will charge while traveling down the road. 

Jack, yours is similar to my 400+ AH of LiFePo and 1080 Watts of Flat rooftop solar which well satisfies all the electric energy requirements (I run all except AC) in my smaller Class C. Mine charge fine driving down the road, subject of course to sunlight. In the event you do a lot of night driving and/or its cloudy n rainy days on end, you might consider adding a DC to DC charger suitable for Lithium charging. The things I like best about my Lithiums are how they don't experience excess voltage sag even when my Inverter may be approaching 200 amps of battery current and how they recharge so much faster, let alone the reduced weight.

 Congratulations you made some good choices

John T

Edited by oldjohnt
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