Gem gave out, lucky it was close to the house, dash would not light up, eventually when it did gave 520500 error code which based on the manual is related to the 12v Aux battery.
I’m considering replacing it with a LifeP04 but wanted to confirm if the delta charger can support the lifep04 chemistry without anything in between?
Delta spec: supports Lead acid (Wet / AGM / GEL), lithium ion. But it does not list Lifep04.
Don’t overthink it. Just put a little gel cell back in there.
Was this while running? Or did it not wake up from a neighbor visit?.
It is only there to wake the car from sleep. Once started, a charge path from the DC converter should connect and the car will maintain that battery.
If this is the case, you need to look at why that charge path is n longer active. Fuse blown?
Disclaimer: At least that is the way it works in my head. Actual reality may differ in the real world.
It was both, when the wife called it was stuck down the driveway. I got it going, went down the hill and it died during the drive. Waited a min and it came back to life so I could drive it back home and parked it. Put a meter on it and after it fired up it read 14v. Shut it off and voltage dropped to 9 than would fluctuate from 1-5v and back up to 11. Just odd behavior. So I ordered a battery from Amazon should be here tomorrow. Has internal BMS so should work with the delta.
Ps sent you PM, let me know what day works best. Thanks
I have replaced the 12v battery with lithium no problem. Fyi Deltaq does not charge the 12v battery, bcm does.
Thanks for the confirmation.
Got the battery, 12v 20aH, 60% charge when it arrived, fully charged it. Oem bracket didn’t fit, so made my own bracket out of aluminum. Very light compared to oem setup with battery and bracket. Didn’t need them b/c of the tight fit, but added two monster zip ties for added measure.
Let’s see how long it lasts, this brand had the best reviews on Amazon. All the cells probably come from the same factory, they just brand it with their own cases. MFG claims A grade cells but time will tell.
Nice chins, man…
.
.
.
.
20ah, thats a big battery. Mine is 6ah! . Nice job on the bracket
Thanks, didn’t take long to make it, used aluminum I had lying around from other projects, its crude but it works. The factory battery is 12ah, i figured a little bigger won’t hurt since I plan to put in some interior led lights for the wife at night when she is loading/unloading the pup. I also doubt it is really 20ah, likely it’s closer to 16/18ah. Someone actually drained it and measured it and got 18aH so I take the marketing with a grain of salt coming from china.
The real fun will come with the HV conversion, still have your charger sitting on the shelf, hoping to start that project soon 
Something to consider when replacing Pb batteries with Li is that Pb batteries don’t like being discharged below 50% rated capacity so a 12ah Pb is at best good for 6ah while a Li battery can be taking to close to 0% capacity but often you want to leave a bit in the battery since going below ~3.0v /cell can cause damage to the battery especially when it’s a slow discharge. A higher load discharge will see some bump back up when the load is removed. Not much but some and that ends up a good thing.
No harm in going bigger and now you’ll have plenty of runtime for that lighting. I would put the lighting on a timer if it isn’t already. Just so when it’s forgotten to turn it off it doesn’t kill the battery.
I’m just trying to get the full picture on how the late cars are wired up.
it sounds like On the +14 cars there is no DC converter active until you KeyON? Then DC Converter and 12v accessories become active?
What AF8 wants to do with his little Lifepo4 battery is to power some accessory lighting without needing to KeyON?
There is no MainSwitch that fully disconnects the battery when away from car?
Not easily accessed. It’s a plug under the hood.
These batteries have a bms, so no damage running them dead.
Hi dougl, the battery has an internal BMS so it should prevent over discharge and overcharge along with some other basic protections.
I’m likely to wire into the existing single overhead light and switch in the dash once i find out what the voltage is but no plans for a timer.
I believe if you remove the key from the ignition it kills the overhead light. So that should also help, trying to keep it simple and hopefully common sense to turn off the light will be enough and key removal.
@AssyRequired plan to use the existing wiring for overhead led unless its some odd voltage. But I do plan to run the HV LCD to it b/c it requires 12v input to turn it on, that for sure will be hardwired to this battery.
"I have killed drained the little 6ah too low multiple times and bms shuts it off. To wake it up you just introduce a 12v charge to it. The problem is accessing it under the dash. So just installed a 12v power outlet in the dash. Now I can reverse charge it when I kill it again. I think the bcm probably charges this little thing to fast, have a 10ah LFP ready to install but it weighs 5 ounces more. Don’t want to hurt performance.
My point being that there is a DC Converter that supplies all of the 12v power for your accessories. It down converts power from your main pack.
It is not the responsibility of this battery. It is just there to wake up the car when you turn the key. You could put an 8D battery from a diesel truck in there and it won’t really help the function of keeping your accessories running longer. (but it might do some interesting backfeed if you decide to wire in a microwave or something).
You are right, in my case the LCD unless something else i can think of will run directly on this pre any converter provides power so the draw should be minimal in theory. The only downside to the primary light switch is the key has to be in the ignition, its dark out so i might just wire in the interior led strip directly to the 12v battery. Have to chew on it and see what the Mrs wants.
I was thinking of adding this like you did with the cigarette lighter so i can just bring in the charger and charge it or just monitor the battery over time.
The bmc actually keeps the 12v battery charged from the main traction battery. Can’t remember if it is time related or voltage related but it turns on and tops off 12v battery.
It does this on it’s own? Neat.
I just figured it was user input at keyON event.
Plugged in or key on also triggers charging of 12v.
It’s not that complicated. Dc converter outputs rated voltage for floating a 12v battery.
Whan car is active it is paralleled to the battery through the Dc converter relay.
ps.
12v battery goes to one side of key switch. No load on it when key is off. This may have been changed in later models to feed 12v regulator in bms, which supplies high side of control relays…
