LiFepo4 top balancing equipment recommendations

[Ian]

So in a recent video Will Prowse recommended using a dc charger to charge up LiFepo4 batteries to 95%. Then to use a bench top DC power supply set at 3.6 V to top balance them. Once the current reaches 0 they are balanced.

I’ve been looking at chargers and bench top DC power supplys and am not sure what I should get. Can someone with experience recommend a specific charger and bench top dc power supply? I’m using 16 180ah calb cells. A quality budget option would be ideal.

 

[FilterGuy]

So in a recent video Will Prowse recommended using a dc charger to charge up LiFepo4 batteries to 95%. Then to use a bench top DC power supply set at 3.6 V to top balance them. Once the current reaches 0 they are balanced.

I’ve been looking at chargers and bench top DC power supplys and am not sure what I should get. Can someone with experience recommend a specific charger and bench top dc power supply? I’m using 16 180ah calb cells. A quality budget option would be ideal.

I just use this
https://www.amazon.com/gp/product/B07ML2MP9Q.

1. Start with the batteries disconnected and set the desired end voltage and the amp knobs turned all the way down.
2. Connect the cell(s)
3. Turn up the current to whatever rate you want for the constant current.

• For assembled solar batteries you will usually hit the power supply limit before you hit the charge limit of the cells.
• If the cells are already charged, you might might not be able to turn the current up very high before the voltage limit prevents it from going higher.

At this point you need to watch the current, when it gets down to a few hundred mA, the charging is done and you need to take the cell(s) off the power supply. This is the primary difference between the power supply and a true charger. A true charger will either quit charging when the current drops off (preferred) or it will drop the voltage to a float level.

 

[ghostwriter66]

I just use this
https://www.amazon.com/gp/product/B07ML2MP9Q.

1. Start with the batteries disconnected and set the desired end voltage and the amp knobs turned all the way down.
2. Connect the cell(s)
3. Turn up the current to whatever rate you want for the constant current.

• For assembled solar batteries you will usually hit the power supply limit before you hit the charge limit of the cells.
• If the cells are already charged, you might might not be able to turn the current up very high before the voltage limit prevents it from going higher.

At this point you need to watch the current, when it gets down to a few hundred mA, the charging is done and you need to take the cell(s) off the power supply. This is the primary difference between the power supply and a true charger. A true charger will either quit charging when the current drops off (preferred) or it will drop the voltage to a float level.

And i like this one .. basically the same thing .. just less knobs and smaller size ...same AMPs though ..

Amazon.com

 

[Ian]

I just use this
https://www.amazon.com/gp/product/B07ML2MP9Q.

1. Start with the batteries disconnected and set the desired end voltage and the amp knobs turned all the way down.
2. Connect the cell(s)
3. Turn up the current to whatever rate you want for the constant current.

• For assembled solar batteries you will usually hit the power supply limit before you hit the charge limit of the cells.
• If the cells are already charged, you might might not be able to turn the current up very high before the voltage limit prevents it from going higher.

At this point you need to watch the current, when it gets down to a few hundred mA, the charging is done and you need to take the cell(s) off the power supply. This is the primary difference between the power supply and a true charger. A true charger will either quit charging when the current drops off (preferred) or it will drop the voltage to a float level.

Nice man that looks like a good unit that comes with some heavy duty leads. Thanks for the recommendation?.
With only 10 amps though I’m thinking it would take forever to charge up 16 180ah calb cells. All my cells came balanced at 3.25 volts. I was planning on putting them in parallel in groups of four. Then charging them up and top balancing them to 3.6V. If all I was using was a dc power supply with 10 amps that would take ages.

 

[Ian]

Ni

And i like this one .. basically the same thing .. just less knobs and smaller size ...same AMPs though ..

Amazon.com

Nice thanks for the recommendation. The only thing I don’t like about that one is the leafs that come with it are limited to 6 amps.

 

[Craig]

I use this they also have a 15 volt 60 amp model

https://www.amazon.com/gp/product/B00L4LC9XK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[ghostwriter66]

I use this they also have a 15 volt 60 amp model

https://www.amazon.com/gp/product/B00L4LC9XK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Now THATS a charger ... LOL

 

[Ian]

I just use this
https://www.amazon.com/gp/product/B07ML2MP9Q.

1. Start with the batteries disconnected and set the desired end voltage and the amp knobs turned all the way down.
2. Connect the cell(s)
3. Turn up the current to whatever rate you want for the constant current.

• For assembled solar batteries you will usually hit the power supply limit before you hit the charge limit of the cells.
• If the cells are already charged, you might might not be able to turn the current up very high before the voltage limit prevents it from going higher.

At this point you need to watch the current, when it gets down to a few hundred mA, the charging is done and you need to take the cell(s) off the power supply. This is the primary difference between the power supply and a true charger. A true charger will either quit charging when the current drops off (preferred) or it will drop the voltage to a float level.

Do you have a “true charger” that you would recommend? Something I can just plug in to a 110 outlet?

 

[Ian]

Thank you for everyone’s recommendations in the end I went with a Tekpower 40 amp dc power supply. I’m inpatient and it seems like a nice unit. I’ll probablly charge at 30 amps. TekPower TP1540E DC Adjustable Switching Power Supply 15V 40A Digital Display

I’ll let you know how it goes.

 

[Walef]

Can somebody please provide the link to Will's video clip on DC to DC charger balancing. Unfortunately I cant' find it in the table.
I believe the video comments on 'gostwriter66' contribution to the step by step balancing method with DC charger I read a while ago somewhere in the forum.

Thank you very much!

 

[FilterGuy]

or

 

[ghostwriter66]

Can somebody please provide the link to Will's video clip on DC to DC charger balancing. Unfortunately I cant' find it in the table.
I believe the video comments on 'gostwriter66' contribution to the step by step balancing method with DC charger I read a while ago somewhere in the forum.

Thank you very much!

Hi .. so my comments were directed more to how we do it at work ... our batteries are typically much larger (some of them are 3.2V 4000aH!!) and once we balance them we typically NEVER balance them (nor do we have to) ever again because honestly - once LFP is top balanced - they remain that way for a long time ... For the batteries we do check we normally only do annual checks ... We also charge to different voltage plateaus and then rest and check again because once again our batteries are pretty large and this sort of lets us know right away (so as not to waste time) if there is a bad cell or not - no need to charge for 24 hours to find out one of the cells won't stabilize)

BUT @Will Prowse did a great video on how to do DC balancing and is totally 100% right in that you can skip many of my charge plateaus I recommend and just hit it with a 3.65V (?) per cell charge and then TOP balance it from there (don't quote me on the 3.65- please watch the video (I can't seem to find it right now - I just got off shift and my mind is tired) ... Thx

 

[Walef]

or

@ filter guy
Thx for providing the links. I was after the top parallel balancing video Will pubished a while ago, however, my initial request was misleading on this -sorry for that-
Meanwhile, I fully read and digested the entire parallel balancing thread and believe that I'm up to date on procedure and faith orientation as long as principle design issues are concerned.

 

[Sgt Raven]

Thank you for everyone’s recommendations in the end I went with a Tekpower 40 amp dc power supply. I’m inpatient and it seems like a nice unit. I’ll probablly charge at 30 amps. TekPower TP1540E DC Adjustable Switching Power Supply 15V 40A Digital Display

I’ll let you know how it goes.

Remember you have to use the rear output for over 5A on that PS. For 30A you want at least 10AWG and 8AWG for 40A.
Here's a link for it, for others who want to see it.

https://www.amazon.com/TekPower-TP1540E-Adjustable-Switching-Digital/dp/B015QHVJP6

 

[Ian]

Remember you have to use the rear output for over 5A on that PS. For 30A you want at least 10AWG and 8AWG for 40A.
Here's a link for it, for others who want to see it.

https://www.amazon.com/TekPower-TP1540E-Adjustable-Switching-Digital/dp/B015QHVJP6

Yeah I’m using the back port and the unit came with 10gauge 1.5-2 foot in length. I’m actually not liking this unit all that much, but I can’t complain to much since it was a relatively good price. The thing that sucks is the voltage display rounds to the nearest 10th. You have to use a multi meter on the back port to dial in 3.65 volts, but the display will say 3.7 since it rounds up. Also, if the back port is reading 3.65 volts the front port reads slightly less at 3.64. The manual it came with is pretty useless too. But it works for what I want it to do. The other more accurate units I’ve seen cost substantially more.
The thing I can’t figure out is if you can do continuous voltage and limit the current at the same time. If I have the voltage set and I try to dial back the current the continuous voltage turns off and the voltage starts to wonder. The manual doesn’t cover this at all. It just says to not use more than 32 amps for longevity of the unit.

 

[Sgt Raven]

Since I only have the coarse adjustment on mine, it's like that, too. That's what happens with a single adjustment knob. Plus mine is a 0-30V.
I need to hook up with my friend who has a big dollar Fluke DMM and check my cheapy one aginst his. See how far off mine is at 3.5V and 13,8V. Those are the around the 2 ranges I'm interested in.

 

[Ian]

So after days and days of slowly charging my battery bank and getting everything top balanced I was finally able to fully assemble my battery today. The 4 groups of parallel cells all showed either 3.600 or 3.601 prior to making the series connections. I’m still waiting on my bms to arrive prior to doing the final tourqe down and there installing the lock washers. Once connected my meter showed 14.4V. I can’t wait to capacity test the battery after the bms is installed. It feels good to be making progress though.

 

[Sgt Raven]

So after days and days of slowly charging my battery bank and getting everything top balanced I was finally able to fully assemble my battery today. The 4 groups of parallel cells all showed either 3.600 or 3.601 prior to making the series connections. I’m still waiting on my bms to arrive prior to doing the final tourqe down and there installing the lock washers. Once connected my meter showed 14.4V. I can’t wait to capacity test the battery after the bms is installed. It feels good to be making progress though.
View attachment 8391

Do you have a crane to lift that thing? What's it weight, 200-250 lbs?
ETA: I had to save your pic on my computer, It looks too good not to.

 

[Ian]

Lol 250 lbs but it isn’t that bad with two people. I actually decided to get a floor lift from harbor freight to put heavy things like it in and out of the van. When the van is parked in the Sacramento summer heat I will need to remove the battery when I’m not using it. Otherwise I’m afraid it will get hotter than 113 F in the van. I need to move to the coast soon lol. Maybe when I finish the van I’ll move to Santa Rosa or Sant Cruz.

 

[Will Prowse]

So after days and days of slowly charging my battery bank and getting everything top balanced I was finally able to fully assemble my battery today. The 4 groups of parallel cells all showed either 3.600 or 3.601 prior to making the series connections. I’m still waiting on my bms to arrive prior to doing the final tourqe down and there installing the lock washers. Once connected my meter showed 14.4V. I can’t wait to capacity test the battery after the bms is installed. It feels good to be making progress though.
View attachment 8391

Nice cell configuration!!