Renogy 100w suitcase and Lithium

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Immulator

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Apologies if I've missed this answer somewhere, but will a Renogy 100w suitcase panel with the PWM controller harm a 100ah 12V LiFePO4 battery pack? I chatted online with a Renogy salesperson but I don't think he understood because he tried to sell me something called The Lycan Powerbox, which does not appear to be a solar panel at all.
Last month, I bit the bullet on the battery for a recently acquired conversion van and have been charging with a Tenergy 12.8V LiFeP04 charger by either generator or plugging into a wall outlet. I am going to the Texas Star Party in a week and need something to set out in the West Texas sunshine. Later on I will acquire a lithium charge controller and rooftop panels, but as a temporary measure will the Renogy product provide at least some charge without damaging the cells? Once I can run the generator without disturbing other, or plug in, I can use the Tenergy charger for a full charge.
 

akrvbob

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The Renogy panel will not hurt it, but it also will not treat it the way it wants to be treated. By not being charged properly, it will slowly deteriorate and fail sooner. So treat it like a supplement to proper charging and you will be okay. If you go too long with just the Renogy panel expect the battery to die soon.
Bob
 

GotSmart

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Immulator said:
Apologies if I've missed this answer somewhere, but will a Renogy 100w suitcase panel with the PWM controller harm a 100ah 12V LiFePO4 battery pack? I chatted online with a Renogy salesperson but I don't think he understood because he tried to sell me something called The Lycan Powerbox, which does not appear to be a solar panel at all.
Last month, I bit the bullet on the battery for a recently acquired conversion van and have been charging with a Tenergy 12.8V LiFeP04 charger by either generator or plugging into a wall outlet. I am going to the Texas Star Party in a week and need something to set out in the West Texas sunshine. Later on I will acquire a lithium charge controller and rooftop panels, but as a temporary measure will the Renogy product provide at least some charge without damaging the cells? Once I can run the generator without disturbing other,  or plug in, I can use the Tenergy charger for a full  charge.

The Lycon Powerbox is not even in production yet!   :mad:

Renogy is not communicating well.  :rolleyes:

The powerbox is a 75 ah battery system that is supposed to be 100% dischargeable.

http://www.renogy.com/lycanpowerbox.html
 

blars

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Charge controllers designed for lead-acid CAN and will damage LiFePO4 batteries. Unless you have very large charge current on a discharged battery, you should never have more than 14.0 v applied to the terminals of a 4-cell LiFePO4 pack. Also, once the charge is complete you must stop charging. (float at 13.4 v or less effectivly stops charging.)
 

29chico

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Immulator said:
Apologies if I've missed this answer somewhere, but will a Renogy 100w suitcase panel with the PWM controller harm a 100ah 12V LiFePO4 battery pack? I chatted online with a Renogy salesperson but I don't think he understood because he tried to sell me something called The Lycan Powerbox, which does not appear to be a solar panel at all.
Last month, I bit the bullet on the battery for a recently acquired conversion van and have been charging with a Tenergy 12.8V LiFeP04 charger by either generator or plugging into a wall outlet. I am going to the Texas Star Party in a week and need something to set out in the West Texas sunshine. Later on I will acquire a lithium charge controller and rooftop panels, but as a temporary measure will the Renogy product provide at least some charge without damaging the cells? Once I can run the generator without disturbing other,  or plug in, I can use the Tenergy charger for a full  charge.

I agree with Blars that 14.0v max charge voltage into a 4s lifepo4 battery pack if you want it to live a long and happy life.  I personally end the charge of my lifepo4 pack at 13.8-13.9v.

I did some research into the Tenergy chargers and went to a data sheet as well.  Since you did not state which Tenergy charger you are using I researched the Tenergy 1.5-10 amp chargers.  It looks like these chargers have a boost phase (constant current) that is programed to end at 14.6v (3.65 volts per cell).  Yikes!!!  The charge parameters of those Tenergy "lifepo4" chargers look suspiciously like those found in a basic multi-stage lead acid chargers to me.

I suggest that you consider putting an accurate voltmeter on your Lithium pack when charging with the Tenergy charger and manually end the charging when it reaches 13.8-14.0v max.  If you want an even more thorough yet safe charge you can then wait a few minutes and charge the pack up a second time to 13.8-13.9v.

For a safe low voltage disconnect on my Li pack I am using the below linked product set at the two min. cutoff setting:

https://powerwerx.com/automatic-dc-timer-power-switch

IIRC Blars is using a Morningstar MPPT charge controller and programming it for his lifepo4 battery bank with Morningstar's MSview software.  That same software can be used on Morningstar's relatively inexpensive (about $200) Sunsaver MPPT charge controller.  Disabling the temperature compensation that is set for lead acid batteries is a good idea with Li packs.  Besides being able to be programmed to correctly charge your Li battery pack, the Sunsaver MPPT is also a high quality current limiting device that can safely take up to 75v max solar, power supply or high voltage battery bank input.  Lots of options open up with a current limiting device.

Sunsaver MPPT link:

http://www.morningstarcorp.com/wp-content/uploads/2014/02/SSMPPT_ENG10_1111.pdf

In the interest of safety, I would suggest that if it is possible to access the terminals of the individual cells in your pack with a volt meter and determine if all four cells are in balance.  They each should be very close to the same voltage as each other.  I am suggesting this because it is very likely that your Li pack has been charged to 14.6v a number of times and when these Li packs get charged over 14.0v they are very likely to come out of balance.
 

Oberneldon

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I was looking at lifepo4 packs and see that some come with the individual cell balancing circuits built in to protect the cells during charging. I gather that not all packs come with this feature from my readings.

Brent


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29chico

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Oberneldon said:
I was looking at lifepo4 packs and see that some come with the individual cell balancing circuits built in to protect the cells during charging.  I gather that not all packs come with this feature from my readings.

Brent


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Correct, not all lifepo4 packs come with balancing systems.  Balancing systems were first created for the electric vehicle (EV) crowd who are are often very much into performance and range.  Some EV folks  want to get every watt possible out of their battery banks.  So they charge them to higher voltages and discharge them lower than the house/RV/yacht lifepo4 users need to.  When charging to the max and discharging deeply lifepo4 cells in a battery pack are way more likely to go out of balance, and that is when big problems can occur.  

For 12v house battery bank applications charging to 13.8-14.0v and not discharging below 12.6v is much kinder and gentler on the lifepo4 cells in a pack.  When charged /discharged in this manner the individual cells tend to stay very close to each other in voltage.  Yes, one does give up some of the total watts available per discharge by doing this, but nowhere near the 50% discharge limit that lead acid battery users have to observe to avoid damaging their battery bank.

A number of very experienced lifepo4 users are now of the opinion that the extra complication of a balancing system results in more parts to fail and potentially damage the battery bank.  So they limit the range of their charge/discharge cycles to somewhere close to my kinder and gentler voltages given above and self monitor and manually balance the individual cell in their packs on a regular basis.   Many lifepo4 users doing this have reported that they can safely extend the time between the manually checking for the state of balance of their battery banks once the cells have settled in.
 

blars

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Auto-cell balancing IMHO is an unneeded expense that reduces reliiablility. Over voltage protection protects against faulty chargers, under voltage against over-use. Not worth the cost to me.
 

Oberneldon

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Thank you for the detailed explanation. If manual cell balancing is necessary based on individual cell measurements, do you have a recommendation for a charging unit to balance the individual cells?

Brent
 

Oberneldon

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I read that if cells are under voltage from the rest will create overheating and improper charging of the good cells, therefore the reason for balancing .

Is there advantages to buying individual cells and wiring your own battery after first conditioning the individual cells vs buying sealed fixed battery packs?

Brent
 

29chico

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Oberneldon said:
I read that if cells are under voltage from the rest will create overheating and improper charging of the good cells, therefore the reason for balancing .

Is there advantages to buying individual cells and wiring your own battery after first conditioning the individual cells vs buying sealed fixed battery packs?

Brent

I have to get on with a bunch of tasks of my own, so please excuse my passing you on to a link that gets right into what you are asking instead of answering your question directly.  Lots of very good in depth info in the link's 100+ pages...

http://www.cruisersforum.com/forums...or-those-using-them-as-house-banks-65069.html
 

SternWake

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That crusier's forum thread has the best info I have yet read on Lifepo4.  

Mainesail does not seem to be updating his own write up on Lifepo4, but he does share results on that thread.

http://www.pbase.com/mainecruising/lifepo4_on_boats





It will be interesting to see how many cycles these batteries can endure.  So far the ones not longer functioning are one overcharged, overdischarged, or those larger cells which do not like the poundings they get on a sailboat beating upwind.

My hankering for Lifepo4 will at some point be satiated.  Seems precise voltage control is the important consideration when charging, and then not overdischarging the pack too.

All my charging sources, Solar, Grid and alternator, all  have manual voltage control.
My solar controller allows me to fine tune absorption voltage and float
My meanwell rsp-500-15 can do 40 amps from 13,12 to 19.23v
My Vehicles alternator is now controlled by an external regulator whose voltage is adjustable:

https://vanlivingforum.com/Thread-Your-Vehicles-voltage-regulator

I would have to get a charging source for individual cell balancing as I plan to build my own battery pack, when the time comes.

Budget for lifepo4 is my issue now, but also that my AGM is still performing admirably, being worked hard but also being recharged according to its specific needs.

I am looking forward to learning the trends and tendencies of lifepo4 battery technology
 

Immulator

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Thanks you for for the detailed explanation. For the record, I am using this charger, http://www.tenergy.com/01034, which, perhaps, is not the best choice. The battery I bought is advertised as a drop-in replacement with a built-in BMS and I would have to disassemble it to access the individual cells. I have had it just over a week and have given it no hard use. I have charged it twice with the above charger so hopefully not too much damage is yet done. I will monitor future charges and 13.9v will be my goal.
I shall forego the Renogy suitcase and after I return from my trip shall acquire a proper MPPT controller and panels.
 

29chico

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SternWake said:
That crusier's forum thread has the best info I have yet read on Lifepo4.  

Mainesail does not seem to be updating his own write up on Lifepo4, but he does share results on that thread.

http://www.pbase.com/mainecruising/lifepo4_on_boats





It will be interesting to see how many cycles these batteries can endure.  So far the ones not longer functioning are one overcharged, overdischarged, or those larger cells which do not like the poundings they get on a sailboat beating upwind.

My hankering for Lifepo4 will at some point be satiated.  Seems precise voltage control is the important consideration when charging, and then not overdischarging the pack too.

All my charging sources, Solar, Grid and alternator, all  have manual voltage control.
My solar controller allows me to fine tune absorption voltage and float
My meanwell rsp-500-15 can do 40 amps from 13,12 to 19.23v
My Vehicles alternator is now controlled by an external regulator whose voltage is adjustable:

https://vanlivingforum.com/Thread-Your-Vehicles-voltage-regulator

I would have to get a charging source for individual cell balancing as I plan to build my own battery pack, when the time comes.

Budget for lifepo4 is my issue now, but also that my AGM is still performing admirably, being worked hard but also being recharged according to its specific needs.

I am looking forward to learning the trends and tendencies of lifepo4 battery technology

I'm going to buy the below linked R/C charger before I invest in my next Lifepo4 pack.  Apparently it is highly regarded in the EV community for individual cell balancing.  It does not discharge a cell and dump the energy in the form of heat, it puts the energy into a 12v battery.

http://www.amazon.com/FMA-direct-PowerLab-8-v2/dp/B00CDA1GG2

My next Li pack will probably be GBS brand lifemnpo4.  I like the fact that the cells use 4 screws per terminal to to secure the cell interconnects.  They come strapped together in 4s packs.  The manganese doping is touted as giving the cells greater resistance to thermal runaway.

Link to a seller of the GBS cells. They have courteously answered my questions.

http://elitepowersolutions.com/products/index.php?cPath=25
 

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