Yes, when 72v goes away, car is disabled.
I got the Gem running.
So back to topic, making this thing function safely on 90V. I got the xener diodes to drop the voltage to pin 1. Can I buy that resistor coil from you for the contactor? I can also see what my dad has laying around if youād prefer, he has lots of old resistors. Where do you recommend installing that? Am I correct if I say it needs to go around fuse F13? I will probably want you to program my charger shortly if youāre willing. Iām still waiting on China to send my balancerā¦ Thanks!
I need to drop voltage of the 72V at the top left of the contactor on the diagram (where it says CHS1) or before that?
Do you happen to know how many amps the motor draws at peak with the 90V setup?
Iām guessing 400 amps. I easily trip my 300a bms.
WOW 400A!? Do you know what it would draw at the stock 72v config? My BMS is 300A as well.
I wonder if we could put something like this up the line at the fuse instead of the resistor at the contactor to handle the heater as well: https://www.ebay.com/itm/DC-step-down-adjustable-power-supply-36V-72V-96-120V-Out-0-90V-12V-24V-13-8V-30A/143522391374
I thought the motor was rated at 7hp. A HP being 746 watts, 746 x 7hp = 5222 watts, at 90V that would only be 58 amps. Granted the motor will certainly draw more due to the higher voltage we talking about, but something is still way off. They must have some funny conservative rating system somewhere. Iām guessing stock must still be around 200+ amps. 200 x 72V = 14,400 watts or around three times the rated HP.
It actually draws less current if anything at higher voltage.
You asked for peak current. T4 is a 400a controller.
What are you calculating to need peak current?
Itās quite easy to keep under 300a battery current, but whenever I get in a hurry bms trips.
Efficiency is bad on brushed motors. Lots of heat.
I was going to turn it down in sentry sw, but keep getting sidetracked.
I thought two zener diodes drop the voltage too much out of the usable range of the 24S batteries.
I used the device in the photo my pops gave me to dial in the voltage for the controller. He intended it for the contactor is why itās so big. It works perfectly, I can set any voltage drop I want to the controller with a small screwdriver.
I used a couple aluminum 10W 50ohm resistors in parallel on a small heatsink for the contactor (they give a 13V drop) ebay 383298663915.
It all seems to work. Now I have to figure out the charging. Iām curious what voltage the public Samsung lithium profile will charge the battery to so I may try that soon, but Iām thinking I will have to send the charger out to get the 98.5V profile. Let me know if youāre willing to help with that.
Thanks for the guidance to get 24S to work.
I learned my DQCP Delta charger with black dot is not programmable (edit, I was wrong, it can be programmed). I was able to repair a broken 912-7200. I had it programmed with ALG 177, it works great on the bench. Installed the charger, I learned the interlock signal works backwards on the non GEM Delta charger. I switched the green wire to the center on the relay inside the charger and that problem is fixed. ALG 177 needs a battery negative signal on the white wire, that is how my gem is wired so that is already there.
The 912-7200 with ALG 177 works on the bench, but not in the gem, any idea why? The white wire is hooked to the neg terminal through the long thin wire that was there, the green interlock is now wired and working correctly (since I swapped the green wire to the center on the relay inside the charger). Iām going to start jumping wires to the battery to see but I figured you know the answer already so any help would be greatly appreciated.
I hooked the charger exactly as the old charger was hooked up. The negative from the charger goes to the negative input on the speed controller, do I need to move this?
What sw in the 177 charger?
2007 Gem will not have white wire to B-. It will go to temperature sensor.
Green wire is the same on all chargers unless someone changed it.
[quote="Mad_Davey,
I used the device in the photo my pops gave me to dial in the voltage for the controller.
[/quote]
Iām interested in the circuit for a variable voltage drop.
Havenāt found it necessary , but curious.
I am going to post it, I am asking my dad exactly what he used. He wants to make it better, it was originally for the contactor, but seems better to use resisters there and this to be able to adjust the speed control sense volts.
The delta is the 912-7200, I sent it away to Travis to be programmed with 9 lithium programs. 177 is the program you initially suggested for my delta Q and after research it is correct for 4.11V on my 24S battery. I have two delta Q 912-7200 chargers that did not come with the GEM, their default is to send voltage on the green wire when they are charging, and off when they are not. The 912-7200 that came in my golf cart (black dot DQCP) sends voltage on the green wire when NOT charging. Interestingly that charger does not have the little relay inside like the other two.
My wiring does not appear to have temp sensor/s. The white is is a direct connection to a yellow and black wire that follows the main battery cables to the battery negative. I will try jumping that to see if that allows it to start charge.
I wanted to mention to you, when testing the 177 Algorithm, it seems to require the white wire on battery negative without a temp sensor. I noticed when you disconnect the white wire then reconnect to activate charge again it reduces the charge to about 1/3 rate. I am wiring it up with a small relay to the bms24, if a fault condition occurs it can stop the charge using the white wire, if the condition resets itself and the bms turns charging back on the rate is lower allowing a better chance of balancing.
Regardless youāre right itās a hidden temp sensorā¦ ugh. Iāll add a terminal to my relay wire and viola.
Sensor should be connected to a battery terminal. It looks like a big lug.
Show this to Pops. You seem to do things the hard way! 
ps.
I never ran into a DQ with a backwards green wire. The green normally comes from the power out relay. NC.
What about this black dot not being programmable? Another new one for me. 
Cool, that replaces my relay and adds a light. I got an extra micro Panasonic relay, same type as used in the charger for the green wire that I used. That was me not pops, and took a sec and itās tiny. Heās older, stays home lately due to the thingā¦ The DQCP, Iāll try programming it outside the cart now that itās out.
Photos show what I had to do to get the green wire correct. It was that way on two chargers, on this one I had to replace the relay to get it to work. Original config on left.
Pops knows his way around electronics, but he is very methodical. I definitely did not learn most of the stuff he knows. He desined EV chargers and speed controllers as a hobby in the 80ās. He designed the math co-chip in the hp85, first hand held scientific calculator, and lots of other cool stuff for HP.
Everything is working now, thanks. Iām messing around with the heater, I will report back when I have that working properly. Iāll also get the devices used for the voltage adjuster thingy.
Thatās a custom configuration. What were they out of?
The green and white should have 1/4ā qc terminals that plug in next to the output relay on the main board.
The white may still be there. The one next to it will have B+ voltage on it.
Hi
have also seen that charger
the green cable go to a pcb circuit board ontop of relay,i just moved green cable to the relay and all be as normal
Seller said they are from Vantage or Miles EV. Yes there are QC terminals, one with B+ is connected to the red wire that comes up to the relay and becomes the green wire out. I still need to test the other one I got.
I noticed the GEM DQCP charger has the location for the relay, I suspect the 12V signal would be there making it possible for someone to add the relay should need arise, unsure that would happen.
The DQCP black dot Gem charger I have is in fact programmable, I have it out and was able to hook to the programmer. I was not able to do so in the cart, Iām sure I was doing something wrong. It doesnāt matter, itās all working now.
Iām considering making your 2N2222 thingy thanks.
