How to Recondition/Service Your 12V Battery

[dtbaker61]

That DC-DC feature operates like the alternatoe or generator in an ICE car. The 12V battery is constantly under light loads, even when the car is asleep. The DC-DC charging system is supposed to replenish the 12V battery under those conditions. Early builds had a sfotware issue that allowed the 12V battery to completely discharge while the vehicle was asleep. There was a software patch for that.

That said, even old ICE cars without any vampiric electronics occasionally need their 12V batteries topped up.

Lead batteries always have some 'self-discharge'.... AGM are better than the old days with 'floodies', but if you do not drive a vehicle a couple hours every 3 months or so, you are asking for trouble with all kinds of things from dry rot in tires, rodents eating electrical, battery self discharge, etc...

Our EVs are more resistant to storage issues that old ICE with bad gas, seals, and fluids.... but still need to be driven once in a while!

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[breeves002]

I have had two warnings of low battery. One just last week. Both times I just plugged in home charger. Will that resolve charging 12volt battery? My car sat for 3 months after it was built before they shipped it to dealer. So I am wondering if my 12v battery is still not working perfectly.

I was wondering if I drive the car on short trips will that also cause problems with my 12v battery?

I have a First Edition that was built in December and I took delivery in April.

Yes it should but if the BMS doesn't know the correct battery state of charge doing a manual full charge could help solve that problem.

 

[louibluey]

I picked up one of these for another project and almost sent it back. Clore Automotive PL2320 20-Amp Fully-Automatic Smart Charger, 6V and 12V Battery Charger, Battery Maintainer, and Battery Desulfator with Temperature Compensation

Then I used it to try to save a couple of 17AH 12V batteries. It saved one using the 2A setting, the other one probably too far gone. I think I might let it run a cycle or two on MME at the 10A AGM setting.

 

[Xlch59]

I am not sure if the battery is charging when the car is asleep. I know it must not charge in transport mode because my car arrived with a dead battery and had to be jumped to get it to the dealer. This was a July build with updated software. The dealer change out the battery before delivery. The cars on chip hold are sitting for a long period of time.

 

[generaltso]

Just use a voltmeter on the + and - jump terminals with the charger connected to check the voltage. If the charger is off the battery voltage will decay to less than 13.3V. If charger is staying on float mode it should keep it at 13.4V+.

Okay, I hooked up the NOCO again and did some testing with a multimeter. Before hooking it up, the battery read 12.25V. Not sure if that was an accurate resting voltage because I had just opened the door to pop the frunk. When I hooked up the NOCO, bulk charging started at 12.5V and slowly climbed to 14.5V. When it switched into Optimization mode, the voltage dropped to 13.13V and stayed that way until I went to bed last night. When I checked this morning, it's now in Maintenance mode and is reading 12.92V. So it looks like the NOCO is not providing power in Maintenance mode?

 

[Mach-Lee]

Okay, I hooked up the NOCO again and did some testing with a multimeter. Before hooking it up, the battery read 12.25V. Not sure if that was an accurate resting voltage because I had just opened the door to pop the frunk. When I hooked up the NOCO, bulk charging started at 12.5V and slowly climbed to 14.5V. When it switched into Optimization mode, the voltage dropped to 13.13V and stayed that way until I went to bed last night. When I checked this morning, it's now in Maintenance mode and is reading 12.92V. So it looks like the NOCO is not providing power in Maintenance mode?

Yeah, it’s shutting off in maintenance mode so it won’t work for long-term desulfating it seems. Looks like optimization mode is trickle charging? You could unhook it to reset it after it enters maintenance mode as a workaround, then the cycle would repeat.

 

[generaltso]

Yeah, it’s shutting off in maintenance mode so it won’t work for long-term desulfating it seems. Looks like optimization mode is trickle charging? You could unhook it to reset it after it enters maintenance mode as a workaround, then the cycle would repeat.

My friend has a Clore PL6100 that I can borrow, so I'll play with that this weekend. Would you recommend leaving it in power supply mode and manually adjusting the voltage as you describe in the OP or set it to charge mode and let it do its thing?

 

[Mach-Lee]

My friend has a Clore PL6100 that I can borrow, so I'll play with that this weekend. Would you recommend leaving it in power supply mode and manually adjusting the voltage as you describe in the OP or set it to charge mode and let it do its thing?

Set it to 13.7V power supply and let it sit.

 

[generaltso]

Set it to 13.7V power supply and let it sit.

Okay, will do. Should I skip the 6 hours at 14.5V you mention in the OP?

 

[Mach-Lee]

Okay, will do. Should I skip the 6 hours at 14.5V you mention in the OP?

That’s optional if you have time to baby sit it. Your other charger would have done that already to get the battery up to 80% so I’m not as worried. Going straight to float/13.7V will work fine, just takes a little longer.

 

[generaltso]

That’s optional if you have time to baby sit it. Your other charger would have done that already to get the battery up to 80% so I’m not as worried. Going straight to float/13.7V will work fine, just takes a little longer.

Sounds good, thanks!

 

[dtbaker61]

Okay, I hooked up the NOCO again and did some testing with a multimeter. Before hooking it up, the battery read 12.25V.

resting voltage of 12.25 does not sound like a healthy battery or on board system.

Rather than external chargers, you may want to try turning the MME 'on', disable the auto-off timer setting, lock the doors and let it sit for a day to see if the on board system gets your battery up to a good resting voltage (like 12.8 or so).

If not, definitely schedule a trip to Dealer!

you guys got me curious, and I measured mine.... opened the hood, did not turn on the mme, popped off my port plugs, and voltage= 12.4 , with Frunk light on as the only load. I let it sit, with hood open for 15 minutes.... Frunk light timed out, and resting voltage had settled at 12.65

 

[generaltso]

resting voltage of 12.25 does not sound like a healthy battery or on board system.

Rather than external chargers, you may want to try turning the MME 'on', disable the auto-off timer setting, lock the doors and let it sit for a day to see if the on board system gets your battery up to speed.

Agreed, but that was right after opening the door and frunk so the interior lights and frunk light were on. Resting voltage is now measuring 12.9V, but that was not long after disconnecting the NOCO. I'll measure it again after letting it sit for a while.

 

[dtbaker61]

Agreed, but that was right after opening the door and frunk so the interior lights and frunk light were on. Resting voltage is now measuring 12.9V, but that was not long after disconnecting the NOCO. I'll measure it again after letting it sit for a while.

yeah, I left my hood up, and turned off my BT so the MME didn't wake up on approach. Mine is sitting at 12.65 measured at the connection points... a *little* low, but anything above 12.6 at rest is probably fine.

 

[louibluey]

resting voltage of 12.25 does not sound like a healthy battery or on board system.

Rather than external chargers, you may want to try turning the MME 'on', disable the auto-off timer setting, lock the doors and let it sit for a day to see if the on board system gets your battery up to a good resting voltage (like 12.8 or so).

If not, definitely schedule a trip to Dealer!

you guys got me curious, and I measured mine.... opened the hood, did not turn on the mme, popped off my port plugs, and voltage= 12.4 , with Frunk light on as the only load. I let it sit, with hood open for 15 minutes.... Frunk light timed out, and resting voltage had settled at 12.65

My quick check (I added the port plugs, one of the best mods yet!) yesterday afternoon measured 12.1 V.

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