If I understand correctly:

Power supply outputs connected in series, diode on each end(im using 300v 1A) connected to battery terminals, and inputs connected in parallel to ac input (using a c13 power cable with end stripped)

Then charge for ~25 hours until a voltmeter reads 195 volts. Connect it to two light bulbs in parallel to discharge untill it reads a low voltage/they get really dim.

Box fan through it the whole time.

Im finding mixed numbers about how long to charge. Charge discharge 2-3 times? ~25 hours is what the math says, should i charge longer? Do I just come im and test the voltage with a voltmeter at 24 hours to see if its done?

 

195V isn't an absolute. You may or may not hit it.

Charge until ONE of the following is met:

• 25 hours
• pack exit air temp > 100°F
• voltage does not increase for 8 hours
• 20 hours minimum AFTER a discharge to < 120V

Discharge with bulbs in SERIES as you'll probably pop single bulbs.

1X discharge to 106V
2X discharge to 66V

Charge in between each discharge and after 3rd discharge.

 

Could leaving the battery mounted while grid charging and having a box fan blowing over it, so you can feel air circulating be a crude solution? It's also 7-12 degrees Celsius where i live, staying ~4-8 degrees Celsius overnight.

Or is this completely stupid? Just wondering.

 

Completely stupid. I attempted something similar. 0 deg C ambient saw the pack exceed 52 deg C
You must push air THROUGH the pack.

The pack is insulated to prevent cooling air leaks.

 

Cool thank you.

So finally got around to grid charging my battery. Grid charged until it heald 193v for 8 hours. Total charging time was 29 hours. Was that a mistake?

Question two, I was discharging with two halogen 79w bulbs in series, added one in parallel to drain faster because the two weren't really lighting up(again, mistak?) thinking about switching to two of thrn in parallel, or two 40w 220v bulbs in parallel to play it safe.

What im confused about:

If I turn the pack on without any bulbs attached voltage reading slowly crawls to 130v, if I reattach bulbs it's starts falling.

Confused about what I'm doing wrong. How do I know if i reached 106v for the first discharge? Can i move on to the next grid charge?

 

My bulb recommendations were based on 110V bulbs (metric units weren't enough of a clue for me), so 1 79W 220V bulb is sufficient. A second in parallel above 132V is fine.


29 hours is fine, but it's at the high end of acceptable. Per the instructions:

Charge until ONE of the following is met:
25 hours
pack exit air temp > 100°F
voltage does not increase for 8 hours
20 hours minimum AFTER a discharge to < 120V

You disregarded the first criterion.

Come on 3 years of EE study guy... Are you an old fart like me and can't remember ****?... Was this like a lifetime ago? V = IR. When you flow a current, you get a voltage change. Remove a load current, voltage goes up. Remove a charge current, voltage goes down. Even empty NiMH seeks to return to near 1.2V/cell like 12V lead acid seeks to return to near 2V/cell after discharge to 10.5V.

You were instructed to discharge to 106V with a load attached. If you have done this, i.e., you attached a bulb until you saw 106V, and it seems like you have, you are finished with the discharge.

Summary:
charge to first termination criteria
discharge to 106V
charge to first termination criteria, 20 hr min
discharge to 66V
charge to first termination criteria, 20 hr min
discharge to 66V
charge to first termination criteria, 20 hr min

Good luck

 

LOL 🤦yes that was obvious. if it makes you feel better I've since switched to studying computer science and won't be practicing as an EE 😅.

I have 2 40w 220v bulbs, and 2 79w 120v, just to clarify for anyone reading this later. Going to use the 79w 120v ones.

So i discharged lower than 30v in my first discharge because I stopped monitoring it.

Guessing that may have been bad for my battery but i should still continue to discharge until 66v both of the next 2 times?

Thank you again.

 

Conduct the 2 discharges to 66V. Even with the 30V discharge, there are likely many cells that have depressed voltage and the subsequent charge/discharge cycles should eliminate the bulk of it.