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Can I use a Benchtop power supply to charge a Lifepo4 battery?

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(@ddistrbd1)
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The battery is a 12.8V 30ah Lifepo4 battery:

ECO-WORTHY 12V Lithium Battery 30Ah Rechargeable LiFePO4 Lithium Ion Phosphate Deep Cycle Battery 

 

I have read that the standard practice is to use a diode to prevent the battery from backfeeding the PSU and damaging it.

Do I need to to do it as safety precaution or can I just set the Voltage to 14.4 and CC to ~5Amp and monitor the charging until the CC reaches Zero?

They sell chargers specifically made for Lifepo4 batteries but what does it do differently?

Appreciate your thoughts.

Ken.

This topic was modified 1 year ago by ddistrbd1

Ken from Peterborough


   
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Ron
 Ron
(@zander)
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@ddistrbd1 NO, get a proper LiFePO4 charger, then contact the battery manufacturer for the charger settings. You can start with mine, and they are probably correct, but I have no idea what your manufacturer has done inside the covers.

Charged/bulk voltage CAN be anywhere between 14.2 and 14.6, with 14.4 being a popular choice.

Float isn't really applicable, but if you set it to 13.6, it will cause no harm.

No equalization, but if that is not an option, set it to 14.4

No temperature compensation

Absorb time is 20 - 30 mins PER Battery (I have 6 so I use 2 hours/120 mins)

Tail current 3%

Charge detection time 3 min

Peukert exponent 1.05

Charge efficiency factor 99%

Charge at about 0.5C normally, but higher rates, like even 1C is possible occasionally.

NO charging below 24F/-5C. I set my alarms and cut-offs a degree higher to be safe.

No discharging below -4F/-20C, and again I set my alarms and cut-offs a degree or two higher, but I have never exposed my batteries to temps that low; even -5C/24F is rare where I live in Canada.

Given the price of these batteries, it makes zero sense to risk charging them with anything that might destroy them or kill you.

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
My personal scorecard is now 1 PC hardware fix (circa 1982), 1 open source fix (at age 82), and 2 zero day bugs in a major OS.


   
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Ron
 Ron
(@zander)
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@ddistrbd1 Tell me more about the battery, pictures, and maybe a manufacturer link?

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
My personal scorecard is now 1 PC hardware fix (circa 1982), 1 open source fix (at age 82), and 2 zero day bugs in a major OS.


   
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(@ddistrbd1)
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Thank you Dave, What brand is your Lifepo4 charger? or maybe I should ask what charger do you recommend.there's a one on Amazon (20-Amp ) that mixed reviews but at least is is for LIfepo4 batteries as well as other types .there's also another good one ( NOCO GENIUS10) but it only goes up to 12 volt(6-12v) and can not be set to 14.5V ,it's a car battery trickle charger and has good reviews  but not sure if it's designed for Lifepo4 ,

Anyhow , I'll keep on searching.

Thanks again.

 

 

Ken from Peterborough


   
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(@ddistrbd1)
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Thanks Ron (sorry I called you Dave in my last post,) the link worked but there's no distributer around me, I found a couple(different brands) on Amazon USA.

Ken from Peterborough


   
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(@ddistrbd1)
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Posted by: @zander

@ddistrbd1 Tell me more about the battery, pictures, and maybe a manufacturer link?

I posted the link but it did not seem to work, here it is again:

https://www.amazon.ca/gp/product/B08VD88Q9K/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&th=1

 

Ken from Peterborough


   
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(@ddistrbd1)
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Ken from Peterborough


   
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Ron
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@ddistrbd1 Ok, those are likely prismatic cells, very standard but one setting I find odd, the max charge voltage is normally 14.6 at least. Most experts recommend 14.4 but anything from 14.2 to 14.6 is acceptable. I don't see any mention of a BMS, but I am fairly sure it has one although I would want to know what functions it has before I spent any money on one.

The Kindle issue is well known on the forum, either use the Amazon link shortener or wrap the link in double-quotes.

My charger is part of an inverter charger and is a 120A charger which is a 0.2C charge rate, from absolutely empty (I don't allow them to fo that low though, maybe 20%) it would take 5 hours, to pump in 600AH, the old LeadAcid batteries were only a useful 225AH and it would take over 8 hours to charge them.

I would not recommend NOCO.

For you, I would recommend the Victron Blue Smart IP65 12V 25A. https://www.victronenergy.com/chargers/blue-smart-ip65-charger

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
My personal scorecard is now 1 PC hardware fix (circa 1982), 1 open source fix (at age 82), and 2 zero day bugs in a major OS.


   
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Ron
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(@zander)
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@ddistrbd1 Here is something important to know about prismatic vs cylindrical cells.

Cylindrical cells radiate heat and control temperature more easily than prismatic cells. Prismatic cells are made up of many positive and negative electrodes sandwiched together leaving more possibility for short circuit and inconsistency.

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
My personal scorecard is now 1 PC hardware fix (circa 1982), 1 open source fix (at age 82), and 2 zero day bugs in a major OS.


   
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(@ddistrbd1)
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Good to know, I am not investing big money on a solar kit or anything remotely close to it, at least not yet but it is an interesting subject to know/learn so any information such as you just mentioned always pique my interest.

Ken from Peterborough


   
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Ron
 Ron
(@zander)
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@ddistrbd1 I assumed as much, but the same gear is used any time you need to charge a battery ((DC to DC) | (AC to DC)) (charger) and/or convert DC to AC (inverter)

That is why my link 

For you, I would recommend the Victron Blue Smart IP65 12V 25A.  https://www.victronenergy.com/chargers/blue-smart-ip65-charger

is for a charger only, 12V at 25A as specified by your battery manufacturer.

QUESTION You seem to be worried about cost, like most of us, so should you tell us your budget? I think it is critical to know more about your use case as well. AS I have not seen any mention of monitoring equipment, local/remote requirements, safety, accuracy, etc.

The block diagram consists of the following (using my country's standards, yours may be different)

Primary reliable input power 110VAC

Charger to convert 110AC to '12'VDC (actually goes as high as 14. x) at enough amperage to do a full change in a time frame you desire (for your battery, they specify 25A, but smaller is ok, it will just take longer)

If you want to know what is going on, a Bluetooth-enabled shunt. By going the Smart Shunt way, you avoid the costs associated with a conventional wall-mounted meter. Here is the Victron link LINK

NOTE If you are only going to put the battery on charge and then remove it, then come back later to charge it again, then the shunt is not that useful. See the charger docs for recommendations regarding monitoring, or just set a timer for at least an hour, maybe 2, to be absolutely certain.

If the batteries you intend to charge do NOT have built-in or accompanying BMS, then you will need to spend between a few tens to a few hundred dollars to get a BMS. I much prefer them built in so no connections can accidentally become disconnected, resulting in a catastrophic event. A Battleborn 50AH battery is a good choice for that. They cost roughly $650USD.

Use a wire calculator to determine what you need in the welders' cable for the run's distance. Some people try to save money on the wire as copper is very expensive these days, but that one-time saving results in a lifetime of losses in the form of heat. NOT wise. 

If you are building for 'conditioned' space, normal copper lugs and bus bars can be used, but if it is in non-living quarters, then only get marine-grade lugs, wire, and bus bars. Of course, heat shrink all connectors using the best quality double wall with adhesive to further protect against corrosion (after all, it is an electrical reaction). You will likely have a minor heart attack when you see the price of marine-grade breakers. I know I did, but your life may depend on it, so bite the bullet. FYI, breakers are sized to save the insulation from burning. You will need, in your simple case, 2, one on the DC input and one on the DC output. 

I think that covers it, other than tools (all tools of good as a minimum quality), wire cutters with your largest grade as the midpoint, manual or hydraulic lug fasteners, heat gun, and the usual collection of normal electricians' tools.

I looked up breakers for you. I highly recommend the Blue Sea brand, this is an area with a lot of fakes so I don't take chances. Here is the link to a 30A marine grade breaker LINK  here is non-marine grade, 1/5 the cost, but I would never use LINK

I recommend a fellow called Will Prowse if you want a more in-depth understanding. Check the following link for an overview of him, then watch some videos and maybe buy his book. Yes, it's mostly about solar and RVs, but the engineering for batteries, chargers and misc stuff is all the same. NOTE NOTE search his YT chan when learning about a product as he will do follow-up reviews in case they 'cheaped out.' This happened many times. This is how science works, we change our minds when the facts change, but the other guys do not. Check this link to get an understanding of Will LINK

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
My personal scorecard is now 1 PC hardware fix (circa 1982), 1 open source fix (at age 82), and 2 zero day bugs in a major OS.


   
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(@ddistrbd1)
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@zander , that last post of yours covers a lot of good information, thanks .

I understand the logic behind a worry free /top quality tools or instruments  and since you don't know my budget you can only start from the very top .

Right now I got all the information I needed and already bought my first Lifepo4 battery for the price of $200 Canadian$, I also ordered a$100 on a charge which is lifepo4 specific and does not charge any other type of battery. 

all of this was to give you an idea on how much I'm willing to spend and therefore the project at hand can not be anything elaborate.

I priced the chargers you linked, found a couple of them on Amazon dot ca and they were way above my budget but they gave me an idea how expensive they can be, the one I bought was from the store you dislike the most (Ali EXpress) but I'm sure you agree that for many of us newbie hobbyists that store is a godsent, but let's not go there, opinions vary.

I learned a lot from this brief conversation with you, it was important for me to know why I couldn't just use my benchtop PSU to charge the 30ah battery and asked the same question from the amazon sellers and reviewers/ others,and came to a consensus that buying a proper charger is a wiser move than I thought.so I did but not the best of the best.

I'll see how it performs when I receive it in 2 weeks.

Thank you again for your posts,links, comments and most of all your patience.

Ken from Peterborough


   
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Ron
 Ron
(@zander)
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@ddistrbd1 I order lots of stuff from Aliexpress. Not sure where you got the idea I don't. The battery looks like a typical prismatic with pros and cons, which I am sure you are now informed of. If you send me a link to the charger, I might be able to reassure you or caution you, but it will most likely be just a semi-educated guess. Mostly I wish you good luck, but 'play' with it outside on a concrete surface. Do NOT try to put out any fire if t should happen with water, get an approved fire extinguisher. Also, wear eye protection, gloves and clothing appropriate to the risk. Sorry if I am sounding negative, but my lawyers tell me that in a public forum like this, we must be careful with what we say, or there can be very serious repercussions.

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
My personal scorecard is now 1 PC hardware fix (circa 1982), 1 open source fix (at age 82), and 2 zero day bugs in a major OS.


   
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Ron
 Ron
(@zander)
Father of a miniature Wookie
Joined: 4 years ago
Posts: 7425
 

@ddistrbd1 I do a few Amazon reviews and can tell you many of them are either paid-for or village idiots with a free unidentifiable platform to spout nonsense on. Remember, some still think the Earth is flat, or we faked the moon landing 6 times. Because you bought it on Amazon, if something is wrong with it, returning it is simple, so give it a good workout for the first month or whatever the return window is. I really hope to hear that all is well and working well.

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
My personal scorecard is now 1 PC hardware fix (circa 1982), 1 open source fix (at age 82), and 2 zero day bugs in a major OS.


   
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(@ddistrbd1)
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Posts: 44
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Posted by: @zander

@ddistrbd1 I order lots of stuff from Aliexpress. Not sure where you got the idea I don't.

I must have misjudged your replies. anyhow it's good to know you're also a frequent buyer of that store.

Posted by: @zander

The battery looks like a typical prismatic with pros and cons, which I am sure you are now informed of.

I'll try to wrap to this battery in double quotes.but you already know which battery I'm talking about.

Posted by: @zander

If you send me a link to the charger, I might be able to reassure you or caution you,

The [[charger]] is also available on Amazon for roughly the same price but the seller sounds a bit iffy, so I 'll wait 2 weeks to get the same thing from Aliexpress. 

 14.6V 20A LiFePO4 charger.

can charge any LiFePO4 battery at a rate of 20 amps.can charge a 50Ah LiFePO4 battery in 2.5 hours, or a 100Ah battery in less than 5 hours, 

It is not recommended to charge lead-acid batteries or SLA, AGM batteries.

Battery Protection: SCP,OVP,OCP,OTP

  • Charging mode: CC.CV.Trickle

Charger output 14.6V 20A ±0.2

Sorry for limited specs, couldn't find more info.

Posted by: @zander

but it will most likely be just a semi-educated guess. Mostly I wish you good luck, but 'play' with it outside on a concrete surface. Do NOT try to put out any fire if t should happen with water, get an approved fire extinguisher. Also, wear eye protection, gloves and clothing appropriate to the risk. Sorry if I am sounding negative, but my lawyers tell me that in a public forum like this, we must be careful with what we say, or there can be very serious repercussions.

Believe me I know what you're talking about, I am 70 years old have had many hobbies, newcomers  who come a site like here(as well as many other hobbyist sites) always get the safest,most kosher answers , in other words you can not give guidance with a warning (you could do it but do it at your own risk" so instead the safest most acceptable advice are the only choice left.

Edit:the link thingy didn't work 

 

 

This post was modified 1 year ago by ddistrbd1

Ken from Peterborough


   
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