Delta Q Charging Voltage

My 2000 Gem is equipped with the original Delta Q charger. I’m using algorithm #13 for 27 series deep cycle lead acid batteries. I noticed the charging voltage at the start is 94Vdc. That seems awfully high for a 72Vdc system. Does anyone have info on what it should be? Thanks!

Interesting…
How are you measuring this? (what points are you probing)
What is the quality of you meter?
Can you verify this with another meter? or check you meter on another known source?
(I know some meters produce questionable readings when their own internal batteries are low.)

Are you sure your 00 car came with this DQ charger as original equipment? I am under the impression the early cars had Zivan or even Schott chargers and the DQ’s were put in when those died.

When you first plug in to charge I bet your batteries sound like a coffee maker. How often are you adding water?

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I have confidence in my meters. I keep a very close eye on my batteries and I seldom let the system voltage get below 71Vdc.
A bit more info: Delta-Q model 912-7200-02. When first plugged in, voltage stays around 84Vdc thru the constant voltage sequence. Then as I understand, above 80% charge it goes into constant current saturation mode. That is the point the voltage jumps to 94Vdc. I’m measuring the voltage across the controller B+ and B- terminals. Thanks for any insight.

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Sounds right. @LithiumGods made similar observations when testing various lead algorithms to use on lithium batteries.
He also noted that it is not every cycle. It’s too bad DQ will not share more information. They are extremely intelligent chargers. Capable of much more than us lowly users are made aware.
72v chargers can be programmed as high as 98.6 volts with lithium sw.

Wow, thanks! Haha, this has to be more than 20 characters to post!

DQ does constant current first and then switches to constant current. Then sometimes it will do an equalization charge. it stair steps its way up to 96v (on #14). I sat and watched it on a volt meters for hours. It can balance a full set of batteries.

Hi, thanks for your response. I think you meant constant voltage first, then saturation with constant current. I just heard from Q that 94Vdc is normal at that stage with algorithm #13. I bought a voltage meter, attached between B+ and B- at the controller and mounted it in the dash. I’d be lost without it now! Next step is to cut a small rectangle in the vertical part of the dash to the right of the storage compartment so I can see the LED’s on the charger.

so I can see the LED’s on the charger.

I’m toying with the idea of making a snap/stick/glue on plate that covers the LED display on the charger, lining up some holes with the lights, and running fiber optics out to a convenient spot on the dash.

Good idea, Grant and I were playing with that when he had a classic Gem.
It seemed easier at the time to do it electronically, so I made some transmit and receiver pcb’s.
Never got past the testing stage.

No, it is cc/cv. The charger puts out 11a and the voltage rises, known as constant current(cc). Once the voltage hits a certain number the charger holds that voltage and reduces current until it drops to a specific number, This is called constant voltage(cv). I don’ think there is a charger that does cv/cc. It is always cc/cv.

Using a hole saw I cut a round hole in the front right corner of the glove box and you can look down and see the top of the QuikQ. I put a grommet on it to fill the hole when not in use.

We decided that the original bi-color led made the most sense. Available ,with leads, from dq. Or using a generic 2-wire led worked just as well.
Most models require removing the cover to plug it in.

the original bi-color led made the most sense.

Yeah, That does make for an easy solution. But it also means using up 14 hot glue sticks If I was to seal up the backside like factory.

My passion for blinky lights probably wouldn’t have been very entertained by that display anyway.

Oops, my mistake. It is cc/cv. My Q charger never makes it to the trickle charge state. It errors out on high battery voltage (2 red flashes). Doesn’t surprise me as it’s outputting 94Vdc at that point, but that’s what the algorithm says it’s supposed to do. This happens after 4 hours charging time. If I set timer to charge for 3-1/2 hours, no error and batteries have full charge. I’m wondering if I ran my batteries very low (69Vdv), if it would complete a full charge cycle?

my guess is the charger has a safety limit set at 4 hours. You wouldn’t want to have that high of voltae for too long. I put individual volt meters on each cell. If one battery goes too high I put a halogen bulb on it to bring it down, lets the others come up.

@LithiumGods My motor on my 2002 e825 (4st) burnt out at the beginning of summer and the car sat until we got back from vacation (On the charger) then we had to take it to put a new (Blue Motor) in it (I know, should have switched to BL then). ANYWAYS now the AGM’s (Polaris labeled Deka’s) are showing their age. Might do a custom SDI94 pack or something similar. What are the peak voltages for the Delta Q for the AGM setting? (I assume its on the correct AGM setting because they have been going strong got 7 years) I know the T-2 Doesn’t like 96+ volts, but I’d like to not mess with the charger stetting’s if i don’t have to and i want to know if i should go with 22, 23, or 24S.(T-2 has already been reprogrammed and did 35mph pretty easily before the motor went out and now it takes a while to reach 26/27 and that’s about all shes got left in her)

the Deltaq wont fully charge a 22s battery, it needs to be updated for lithium with that profile put in it. It will do an 20s ok, problem is that for lead it will look for the temp sensor to charge. The temp sensor will vary charge voltage based on temp so charge voltage will vary. You would have to use the BMS to stop it from over charging. If you are custom building 20 or 21 would probably be closest, you will give up performance not going to 22s.

How do you go about updating the charge profile?