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Discussion Starter · #1 ·
I have an older model Zivan NG3 144 volt charger connected to the VoltPorsche. I currently have 21 Nissan Leaf Modules. Nominal voltage of the pack is 159.6 and max voltage would be 176.4. The Zivan does charge the battery but will not end the charge at the correct voltage of the battery. The Zivan can charge up to 190 some odd volts. I did notice that the charger went to yellow when it reached nearly the max voltage but not green. This sucker will overcharge the Leaf Modules even at that high voltage. I noticed that there is a cover over a small knob that can be turned but when I did I saw no difference in end of charge so not sure what it actually does. Is there anyone out there that can help with that? I found no manual that old that covers that adjustable knob. Below is a pic of the knob uncovered just below the indicator. I want to be able to use this nice charger for charging Lithium Batteries. Anyone have anything I can connect to this and is there a way to change the algorithm for different types of lead acid batteries or NiCad or what ever is in this charger. If I can get an old manual I can likely figure out what I need. I do like the charger.
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I am trying to upgrade from 144v (24) cell lead acid to (45) LiFePO4 batteries.
I am struggling to understand how to set new perimeters.
I found this on-line. These are the adjustment ports but I don't know what battery pack they are adjusting for.
Hope you can help me with settings for my pack.
Learning from your knowledge would be greatly appreciated.
Hoping it is this simple.
James
 

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Discussion Starter · #3 ·
The zivian should charge the LiFePO4 cells just fine. The zivian will just charge them. Keep an eye on the voltages and if you have a balanced pack it should stop charging and hold voltage. Just be sure no cell is over 3.6 volts for cell longevity. There is a surface charge after charging and when allowed to sit that will wick off and the cells should rest at about 3.35 volts per cell.
 

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Looks like my situation is less complicated because I am working with like voltage packs. (both 144v)
LiFePO4 cell voltage is 3.2 and max is 3.65. (3.65 is max for top balancing)
You like 3.35 max volts per any one cell in the pack for safety and longevity.

I am looking at data sheets and my NG3 (144v) float lead acid at 159.4volts. (I have seen this on lead acid fully charged)
Math: 159.4 divided by 3.35 equals 47.56 cell. If increased my total cell count from 45 up to 48;
that would be right in the safety zone of it being theoretically impossible to overcharge a pack of balanced cells,
If that is correct I can move on to the next challenge of reduced amperage @ 80%.

Is my approach correct?
 

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Discussion Starter · #5 ·
I charge to 3.45 then let rest which will be in the 3.33 to 3.34 v range. Even if you charge to 3.65 the cells will settle into the same range. There is little to gain by charging to any higher voltage.
 

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Math: 159.4 divided by 3.35 equals 47.56 cell. If increased my total cell count from 45 up to 48;
that would be right in the safety zone of it being theoretically impossible to overcharge a pack of balanced cells,
you should be safe with 46/7 cells 159.4/46/47= (46)3.465V/(47)3.391V a cell you could rig a relay to shut of the charger when it switches to float stage.
Later floyd
 

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Sounds good, thanks.

Lithium chargers, I have seen on line, have the same red, yellow, green indicators.
But, I could not find their value. A yellow on my charger means the
pack has reached 80% state of charge and the output amperage is reduced from 11 to 8.3
80% of 159v is 127v Charger reduces to 8.3amps at 127v. (about a 25% reduction in amps)
Anyone know what the parameters are for a lithium charger on yellow?

I could top balance, drive the car and then charge while monitoring both the pack voltage and charger amp output.
Adjust to what, I don't know? How, I don't know? Just asking am I on the right path with my thinking?
If I am lucky and things are close enough, I have nothing to adjust.

I am going to put a BMS on the pack but the chip shortage is effecting production. Not good!!
 

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Hi, bit late to the party:

The covered knob is a selector for charge profiles. Not quite sure which is which. Depends on your model.

By the looks of it you do have an "Pb Acid" version - which does come with a CC/CV profile if I'm correct.
If you've got the basic setup like on the sticker, it will overcharge your batteries till close to 198v and then keeps pumping 2A indefinitely - so basically very bad.

Read:


Based on those - I'd say make sure you find the CC/CV profile "IUo" (not sure which on the the dial - please read above) - then get some logic (BMS, Shunt) that, once current during CV phase reaches C/20 or 5% of the Ah - it cuts off the charging. There is a 'start stop' connection just above the control board. Not sure how that works, but you can stop the charger that way.

Also, you can get the charger programmed by Zivan for a fee. Might be a good option too.
 
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