Hey buddy, Im sure that Im missing something here. Im buttoning things up on my car and put it on to charge and I cant get the chargery charger to put out amps. Any settings that I should look at? It was charging just fine the other day.
Cell count 28
Charge Current 10a
End Current 10%
End Voltage 3.5v
Restart Charge Yes
Auto Charge Yes
Iām an ā ā ā ā ā , I I forgot to push and hold life, sorry to waste your time.
Hey Dave, quick question. Could I use the chargery charger as a power supply through the BMS to charge 29 cells? Itās says it goes to 102v. I think I can use an extra cell with your spoof.
Yes, you can. I believe it only does 28s lifepo4, but you can set it to 28s and a higher voltage per cell.
I do the same charging 4s. It only goes down to 5s, but it can be worked around.
90+ volts is on the edge of overheating the main contactor coil. Itās a good Idea to connect a series resistor to limit current.
I have a few spare contractors so I think Iām going to try it! Could you send me a link for a series resistor if you would be so kind.
I did the math for someone once before. Have to search for it.
Measure the coil resistance for me and Iāll make a guess. Thinking 10% to 20% of the coil resistance.
Guessing at wattage if 20% voltage drop = 20v . E*2/R= 400/R
It will dump a lot of heat, but better than in the coil.
This is a Generic coil. (280 ohms?)
FEATURES for your SW200 Style Single Pole Single Throw (SPST) 400A 80VDC 250VAC 12V, 24V, 48V, 60V, 72V, 96V or 120V DC Coil EV Contactor Set
o 400A Contact Switching
o SPST-NO Contact
o Maximum Coil Energy Waste: 18W
o 1.5A Power Draw
Temporarily hooked up the last cell. Disconnected the bms and Iām reading 96.5v. Got code 77. Going to turn on my headlights and radio for a while to see if I can get to 96v. I wish I didnāt convert everything to LED, thisnis gunna take a while.
Shouldnāt take long after charging to drop. Drops a lot even with no load.
If you want to push your luck add a diode in series with spoof. Each diode adds .6v or so.
Band toward controller.
Did you ever clean this up to go public?
The 28s/29s question is interesting.
Ok got it to 96.1v, and HOLY MONKEYā¦it pulls like an animal! Got 38mph on gps. I rode it for about 1.5 miles and it was a savage.
Iāll clean this up either tonight or tomorrow.
This is the contactor I have, I think its a 100amp at 72v/80v
Couldnt I just bite the bullet and get a higher amp/volt contactor like thisā¦
I cant guarentee an economizer will work.
A resistor is a simple fix.
I only need the coil current or resistance to make a good guess.
Ill measure it up tomorrow. I cleaned up the post so go ahead and make it public!
133 ohms? 48watts?
Wow, thatās pretty substantial.
At 100v need 166 ohm total for .6a to flowā
Add about 33 ohms.
I^2 R=12 watts
Guessing 30 ohm 25 watt will be a good start.
Something like this? Can you help me understand how this would be wired?
Yes, connect in series with the coil.
I have 25ohm and 50 ohm.
If you will test voltage at coil using each, Iāll send them to you.
PayPal me a dollar as payment so I can print a label.
If the donāt work, you will know what to buy.
Dave
Should the resistor be before or after the fuse? Paypal on its way.
Doesnāt matter. I would put it on the + side of coil and mount it to aluminum frame or contactor bracket.
