Top Balancing "How to"

houseofancients

Solar Addict
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Nov 29, 2019
Messages
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Liitokala's anwser is "our batteries are sent out after strict inspection, and the capacity of the batteries is in accordance with the description".
No refund.
Never trust again them, they are scammer.
dispute, show them you test results, also contact your cc company and they will be on your side, once liitokala finds out their money is gone, i am very sure they will contact you with all sort of sob stories
 

crozen

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Jun 23, 2021
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dispute, show them you test results, also contact your cc company and they will be on your side, once liitokala finds out their money is gone, i am very sure they will contact you with all sort of sob stories
i showed them all the pictures, but that was their answer. I also have put the link from this thread to show them what we are talking about.
 

418ImATeapot

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Jul 14, 2021
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I have 16 280ah cells that I'm top balancing right now. All the cells but 1 started at 3.27v the other was 3.26. I purchased the power supply that is recommended on this site. They have been charging at 3.40v for about a day and a half now, and are now up to 3.29. The power supply shows it's pushing about 1.6 to 1.8 amps. I have (2) 24v bms. I might pull the batteries apart and connect them in 8S2P to charge a bit quicker. If I do that what should my charge voltage be? Also once that is done do I go back to 16P and charge at 3.4 then to 3.5 then to 3.6. Do I need to let the amps on the power supply really drop to 0 before stepping up the voltage? Thanks!!
 

smoothJoey

mumble...
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Nov 30, 2019
Messages
9,279
I have 16 280ah cells that I'm top balancing right now. All the cells but 1 started at 3.27v the other was 3.26. I purchased the power supply that is recommended on this site. They have been charging at 3.40v for about a day and a half now, and are now up to 3.29. The power supply shows it's pushing about 1.6 to 1.8 amps. I have (2) 24v bms. I might pull the batteries apart and connect them in 8S2P to charge a bit quicker. If I do that what should my charge voltage be? Also once that is done do I go back to 16P and charge at 3.4 then to 3.5 then to 3.6. Do I need to let the amps on the power supply really drop to 0 before stepping up the voltage? Thanks!!
See my signature for a helpful link.
Read the doco on top balancing and If you still have questions I'll be glad to answer them.
 

upnorthandpersonal

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They have been charging at 3.40v for about a day and a half now, and are now up to 3.29. The power supply shows it's pushing about 1.6 to 1.8 amps.

You need to put on proper thick leads with ring terminals (I'm guessing you're using crocodile clamps on the cables that came with the supply). Also, once you have that and see 10A or so, be patient.
 

LVLAaron

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Jul 16, 2021
Messages
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You need to put on proper thick leads with ring terminals (I'm guessing you're using crocodile clamps on the cables that came with the supply). Also, once you have that and see 10A or so, be patient.

I too learned this the hard way. At lower voltages having strong and positive contact is a MUST.
 

LVLAaron

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Jul 16, 2021
Messages
166
Also worth noting... The bench power supplies are junk. Yeah, they work. They're 70 dollars, large, and the one I bought immediately blew up when I powered it on.

I ended up top balancing with an ISDT Q8 (70 dollars, 20 amps!) (They also have a 30 amp version for 100 bucks)


Much more current from this device, and it has other features that are handy if you have DIY packs.
 

418ImATeapot

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Jul 14, 2021
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I put some terminal connectors on it and it's up to about 1.8amp, it's bounced around I think it was about 1.9 when I initially started.
 

Gazoo

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May 12, 2020
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Texas
I think someone mentioned here about using 10ga wire? Should I replace the entire wire, or just put lugs on the wire that came with it? (Yes, using alligator clamps) I got this power supply (https://www.amazon.com/gp/product/B082HXVRNF/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1)
I used 12awg silicone wire with ring terminals and my PS worked great. Some of these power supplies come with 16 or 18awg cable...lol. Not good enough for these small voltages.

You should see close to 10 amps once you get bigger wires and the PS should remain in Constant Current mode until it reads apx. 3.65 volts on the display. Then it will switch to Constant Voltage mode and the amps will drop.

It's very important to set the voltage of the PS before connecting to the cells.
 

Hedges

I See Electromagnetic Fields!
Joined
Mar 28, 2020
Messages
8,365
I put some terminal connectors on it and it's up to about 1.8amp, it's bounced around I think it was about 1.9 when I initially started.

Current shown on power supply about 1.8A? What voltage shown on power supply? What voltage is power supply set to (i.e. what is shown when disconnected from battery?)

When power supply displays lower voltage than its setting, expect amps = setting.
When power supply displays amps lower than its setting, expect volts = setting.

I have 16 280ah cells that I'm top balancing right now. All the cells but 1 started at 3.27v the other was 3.26. I purchased the power supply that is recommended on this site. They have been charging at 3.40v for about a day and a half now, and are now up to 3.29. The power supply shows it's pushing about 1.6 to 1.8 amps. I have (2) 24v bms. I might pull the batteries apart and connect them in 8S2P to charge a bit quicker. If I do that what should my charge voltage be? Also once that is done do I go back to 16P and charge at 3.4 then to 3.5 then to 3.6. Do I need to let the amps on the power supply really drop to 0 before stepping up the voltage? Thanks!!

If power supply is set to 3.4V, that is low on knee of the curve. Not much balancing.
If set to 3.65V that would be high on the curve. Current should remain high longer, and balancing will be much closer.

If supply is set to 3.4V, displays 3.29V, and current is low, that seems odd.
But possibly the missing 0.11V is a drop inside the power supply, regulation is happening at one point and meter is reading another.

I would disconnect battery, set supply to 3.65V, reconnect battery. Then observe readings.
 

418ImATeapot

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Jul 14, 2021
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Current shown on power supply about 1.8A? What voltage shown on power supply? What voltage is power supply set to (i.e. what is shown when disconnected from battery?)

When power supply displays lower voltage than its setting, expect amps = setting.
When power supply displays amps lower than its setting, expect volts = setting.



If power supply is set to 3.4V, that is low on knee of the curve. Not much balancing.
If set to 3.65V that would be high on the curve. Current should remain high longer, and balancing will be much closer.

If supply is set to 3.4V, displays 3.29V, and current is low, that seems odd.
But possibly the missing 0.11V is a drop inside the power supply, regulation is happening at one point and meter is reading another.

I would disconnect battery, set supply to 3.65V, reconnect battery. Then observe readings.
Ya the current on the PS is about 1.8A, when it's set to 3.4V. I get about 3.29V from the battery when the PS is disconnected.
I read on here that you should run 3.4 wait for amps to drop to near 0 then progress up to 3.5 then 3.65
@GazzooI think my wires are 14ga20210823_123614.jpg
 

upnorthandpersonal

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Put it to 3.6V and see if you can pull 10A. Those cables look thin and also those banana plugs... would be better being ring terminals.
There are a few different ways to do balancing, and going up in steps being one of them, but not really needed. You can set the supply to 3.6V right away (while disconnected from the battery).
 

418ImATeapot

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Jul 14, 2021
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Put it to 3.6V and see if you can pull 10A. Those cables look thin and also those banana plugs... would be better being ring terminals.
There are a few different ways to do balancing, and going up in steps being one of them, but not really needed. You can set the supply to 3.6V right away (while disconnected from the battery).
If I up to 3.6V it pulls about 5A. Those terminals are full rings not the half ring ones you can take off without fully removing the nut. (idk if they are super high quality ones. they came in a kit with a bunch of different sized connectors red, blue, yellow...)
 

418ImATeapot

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Jul 14, 2021
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So just did some testing with my volt meter. At the connection on the PS (3.6V, 0A), at the end of the leads not connected to battery (3.6V, 0A), and at the connections with the leads connected to battery (3.3V, ~5A)
I'm surprised the voltage at the leads with them on the battery doesn't show 3.6V?
 

upnorthandpersonal

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Your supply will drop the voltage to sustain the max current (constant current mode). This is normal. However I think your leads are too thin and the connections not good enough. You should pull maximum current with the supply set to 3.6V (is this supply rated for 10A?) - if it is a 10A supply, improve the leads with better ring terminals and thicker wire.
 

418ImATeapot

New Member
Joined
Jul 14, 2021
Messages
16
Your supply will drop the voltage to sustain the max current (constant current mode). This is normal. However I think your leads are too thin and the connections not good enough. You should pull maximum current with the supply set to 3.6V (is this supply rated for 10A?) - if it is a 10A supply, improve the leads with better ring terminals and thicker wire.
Ya it's a 10A supply.
 
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