Charging Lithium

[rahvin2j3]

Hi Guys,

Got a question. Based on what I've read here and somewhere else, charging AGM daily is required (be it via solar or alternator or both) because it is "happy" if it is kept at 100%. 

Will it be the same story for Lithium?

Thanks.

 

[whitewolf]

In general, I'd say no. Lithium just doesn't care. Totally laid back, man.

Sent from my PH-1 using Tapatalk

 

[John61CT]

Staying sitting at Full or high SoC is not healthy for LFP, why you don't want to Float.

Opposite of lead.

However that applies more to storage, when not being actively cycled.

In use, ideal is charge to Full or high SoC while or just before a load will start pulling it back down.

And cycling to a shallower DoD is healthier than deep discharging, wrt coddling for longevity.

This curve is a very similar shape to lead.

None of the above is wrt to "damaging" a bank, not recommending expensive automated gear to enforce an ideal pattern.

Just be aware that you will get "even greater" greater longevity to the extent you can follow them.

 

[Oberneldon]

LiFePo4 can come with control circuits inside to manage the battery, self protecting itself. You can also build a battery system with or without adding protection. I only use protected batteries as my total current demand is relatively low.

Charging is specific to the manufacturer specifications. It is a technology that is still emerging as to what level of charge is best for the chemistry. The same is true on how much discharge you should have before you recharge. Are these factors to consider?

I would say that it's interesting but not compelling. With lead acid I didn't want yo check water level or specific gravity. I didn't want to worry about charging at 32 deg F or below. You can use the battery but just don't charge. I just warm my camper a bit before charging and get to where it's warm in the winter.

So, you can worry about the number of charges by fully charging each day but I don't. I just use mine and solar charges to the manufacturing specifications.

Jump in LiFePo4 is great


Sent from my iPad using Tapatalk

 

[John61CT]

BMS is just last-ditch disaster prevention, nothing to do with proper care for maximizing longevity.

And yes with sealed drop-in type units, C rates are greatly constrained, accessing the prismatic cells directly gives greater quality assurance and flexibility.

But you need to set up at least LVD / OVD protections and yes against charging at low temps

 

[Oberneldon]

I’m in the group that I don’t worry if I get 2K charges or 3.5K charges as there are other variables such as maintaining a certain LiFePo4 battery temperature.

BMS (Battery Management System) is great for the average user who wants the benefits that come with LiFePo4 chemistry.

I don’t know of anyone other than a techie who wants to be checking lead acid battery specific gravity. The same for LiFePo4 batteries. The average user is fine with a sealed battery with PMS (Power Managment System) and BMS to protect the battery.

There will come a day when other battery chemistry will take the place of LiFePo4 and we may have a day where battery engineers will set new parameters for charging, until then I recommend using manufacturers specified chargers/charge controllers, and related settings.

All a vandweller has to do is enjoy their much improved battery experience. Those with technical skills and want to manage the battery environment can just like the specific gravity example with lead acid.

Enjoy the experience with LiFePo4.

 

[Spaceman Spiff]

For some of us 'checking lead acid battery specific gravity' is to minimize cost.  I chose CG2 FLA batteries because I could afford them and I am careful of my charge parameters and electrolyte condition because I want to maximize my investment (i.e. I want to put off buying new batteries as long as possible).  

IMO learning the conditions which make LiFePO4 batteries happy are even more important because of the much higher investment.  So learning how depth of discharge and charging parameters relates to longevity is critical to keeping your batteries healthy for as long as possible.  Or you can pay someone to do that learning for you.  That is unless you are OK with replacing your batteries sooner than expected.

 

[John61CT]

Yes, if I am spending thousands on a bank, getting double or more the lifetime out of a simple one-time voltage adjustment is worth it.

 

[Oberneldon]

Ah Yes. We are talking about two types of applications. I’m talking about smaller applications of LiFePo4 for vandwellers.

They want a battery / solar system that is a solar panel or two and a battery or two.

They want something that is simple that doesn’t require maintenance. Something that can effectively can be left alone and not worry about it. If they forget and leave something on the LiFePo4 with internal controls auto shuts off without damaging the battery. So many advantages with LiFePo4 over lead acid for these people.

With the new LiFePo4 warrantees of up to 10 years why not install a battery that does just that.

There will always be those that choose to manage their system to a higher level, but there are many small vehicle owners that a simple solution is best

 

[bigskybob]

As far as I can tell by reading the Smart Battery webpage,their lithium batteries are guaranteed for 5 years,but that is only for manufacture defect.When you return a battery under warranty or not it may be 6 months before you get it back.Think I'll stick with the old FLA batteries at $1 per AH.Keeping life simple seems to work best for me.

 

[whitewolf]

Right on! They are an expensive initial investment though. I've had mine a year so that's still like $5 a day for batteries. Whoa! In a couple years that will drop down to a more reasonable price for my outlay. I need them to last about 2000 days to have them cost me $1 a day for "free" electric.

Sent from my PH-1 using Tapatalk

 

[RowanFae]

Is there a technospeak translator that explains any of this in English?
This stuff always hurts my brain

 

[whitewolf]

I try to keep it simple but I do get out geeked. Ha

Sent from my PH-1 using Tapatalk

 

[whitewolf]

If you don't charge non-lithium batteries to 100% everytime it's not good for them. Lithium's don't care and actually prefer a bit less than full charge. I thought that was the original question.

Sent from my PH-1 using Tapatalk

 

[John61CT]

Called Google.

Then ask specific Qs

 

[Spaceman Spiff]

 . . . They want something that is simple that doesn’t require maintenance.  Something that can effectively can be left alone and not worry about it.  If they forget and leave something on the LiFePo4 with internal controls auto shuts off without damaging the battery . . .

Maintenance free systems --- Aren't
Self regulating system --- Don't
Failsafe systems --- Fail
     3 corollaries to Murphy's Law that all controls engineers learn soon after graduation.

All I am saying is that whatever system you choose, when you decide to go off grid, YOU become the power company.  You become responsible for power generation, storage, and distribution.  Your choices:

1. Learn as much as you can about your chosen technology so you can set up, monitor, adjust, and maintain your system for optimum performance and longevity; or at least understand what your automated systems are doing and can periodically check to see that they are working properly.
2. Pay someone else to do it.
3. Risk early (and expensive with LiFePO4) failure.

And a 4th corollary:  Systems fail at the most inopportune time.

 

[bonvanroulez]

RowanFae wrote:
"Is there a technospeak translator that explains any of this in English?
This stuff always hurts my brain"


John61ct wrote:
"Called Google. 

Then ask specific Qs"


Ooh, a little terse but okay, I’ll try a Google search of the numerous acronyms introduced just in this thread…

SoC
Google top result  “System on a chip”
Also, slang for “same old crap”
Wikipedia lists 51 possible meanings for SoC

LFP
Google top result “London Free Press”
Wikipedia lists 14 possible meanings for LFP, including Larry Flynt Publications

DoD
Google top result “U.S. Department of Defense”
Wikipedia lists 21 possible meanings for DoD

BMS
Google top result “Bristol Meyers Squibb”
Urban dictionary: BMS = blowing my s**t
Wikipedia lists 35 possible meanings for BMS
Thankfully, Oberneldon spelled out the term Battery Management System.

C
Google top result “C (programming language)

LVD
Google top result “LVD Strippit” for the LVD Group
Also, “The Low Voltage Directive of the European Commission”
Wikipedia lists 6 possible meanings for LVD, none of them applicable to this thread.

OVD
Google top result “Opthalmic Viscoelastic Devices”
Wikipedia lists 7 possible meanings for OVD, none of them applicable to this thread.

FLA
Google top result “Florida”, “Fair Labor Association”
Wikipedia lists 30 possible meanings for FLA, none of them applicable to this thread.

Qs
Google top result “QS World University Rankings”





SMH = Shaking my head

 

[John61CT]

Providing Google other relevant keywords for context helps. 12V, electric, battery, etc

State of Charge, Depth of Discharge is its inverse

SoH is State of Health

LFP short for LiFePO4

C is current amps ratio to AH capacity

So .5C is 50A for a 100AH bank

Low- / Over- Voltage Disconnect

Flooded Lead Acid

 

[Oberneldon]

Maintenance free systems --- Aren't
Self regulating system --- Don't
Failsafe systems --- Fail
     3 corollaries to Murphy's Law that all controls engineers learn soon after graduation.

All I am saying is that whatever system you choose, when you decide to go off grid, YOU become the power company.  You become responsible for power generation, storage, and distribution.  Your choices:

1. Learn as much as you can about your chosen technology so you can set up, monitor, adjust, and maintain your system for optimum performance and longevity; or at least understand what your automated systems are doing and can periodically check to see that they are working properly.
2. Pay someone else to do it.
3. Risk early (and expensive with LiFePO4) failure.

And a 4th corollary:  Systems fail at the most inopportune time.

Well, a sealed protected LiFePo4 battery is less maintenance than lead acid and much more forgiving and will last longer.

A simple solution in a van can be worry free

 

[bonvanroulez]

Providing Google other relevant keywords for context helps. 12V, electric, battery,  etc

State of Charge, Depth of Discharge is its inverse

SoH is State of Health

LFP short for LiFePO4

C is current amps ratio to AH capacity

So .5C is 50A for a 100AH bank

Low- / Over- Voltage Disconnect

Flooded Lead Acid

Why not simply spell out the terms as you have done here? Your posts are hard enough to read in your mangled English without adding in a bunch of undefined acronyms.