How long does it actually take for the BMS relearn?

[guarnibl]

ALWAYS fully charge new batteries before installation.
Voltages that low - meh, not a great sign for either battery.

Frankly, I'd put two NEW batteries in instead of one that's been that low and has any age on it with a new battery. Not a good mix

The relearning isn't a big deal. It will have learned so fast it's not worth telling people - hey, we're in learning mode and who the heck is even going to know or care anyway?

Two new batteries and be done with it.
Charge both first, then install.
Allow a few hours (not days, hours) for it to relearn.
Get a batteryminder type of device that is made for maintaining batteries - too many chargers charge fine, but for maintaining while sitting - not very good.

I don't know what VOLTAGE the NOCO "maintains" at but some say it's crazy high. They only say they "use a low amperage pulse to maintain" - that's weird to me.

https://bobistheoilguy.com/forums/threads/noco-genius-10-burning-out-batteries.390559/

I'll stick with my CTEK and BatteryMinders. I know that will start a flame war! LOL - oh, well - they do great for me and I've taken batteries out over 10 years.

I did replace both batteries at the same time -- wasn't going to just replace one.

Yeah, I should have just charged them to full to start, didn't do that. ESS is working again -- it took about 5 hours of actual driving over about 5 ignition cycles, and one overnight. My clock still hasn't resynced, lol. It's possible that the batteries were not at full charge from sitting at the store, and thus the relearn should have completed nearly immediately if they were full charge at install. So it makes sense in that case, to not bother telling anyone. I always prefer to have some way of knowing what's going on even if it's verbose but I'm in the minority there.

My NOCO has been great. My CTEK fried my Porsche battery and that's when I switched to Noco 5 years ago ish -- though my CTEK did well for a while. But I know folks prefer their brands for their reason and that's cool. I like the Noco Genius 10 as it's actually capable of keeping a large CCA battery properly maintained. My Genius 2 that I had couldn't keep it as parasitic draw was too high, and when checking spec sheet, it was really designed for smaller motorcycle batteries with lower Amp hour batteries (only up to 40Ah). Thus I moved over to the Genius10 and it's been great ever since.

I'm going to do another test to see what voltage the tender will keep the AGM battery at once it reaches full charge (the old main), without the battery connected and report back. Again, maybe it won't ever reach full as it was down to 6v, we'll see.

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[guarnibl]

Noco brought my Main back to 12.9. We'll see if it holds just sitting there today.
I'm charging the small one to see if it X's out again.

 

[guarnibl]

Didn't hold -- dropped down from 12.95 to 12.5 in about ~4 hours, so running Noco Genius 10 repair mode. Kinda thinking both will just get returned to Oreilly's to refund the core charge.

 

[ShadowsPapa]

Didn't hold -- dropped down from 12.95 to 12.5 in about ~4 hours, so running Noco Genius 10 repair mode. Kinda thinking both will just get returned to Oreilly's to refund the core charge.

Just to verify....that dropped while not connected to anything at all, correct? Out and nothing connected to it.
If that's the case, yeah, that isn't good to drop that my h with no load connected.

 

[guarnibl]

Just to verify....that dropped while not connected to anything at all, correct? Out and nothing connected to it.
If that's the case, yeah, that isn't good to drop that my h with no load connected.

Correct, literally nothing attached. Was just sitting on my garage floor. Doubtful the repair process will save it.

 

[WILDHOBO]

Correct, literally nothing attached. Was just sitting on my garage floor. Doubtful the repair process will save it.

I’d guess it’s toast.

 

[ecidiego]

NOCOs float too low. CTEK crew here.

 

[guarnibl]

NOCOs float too low. CTEK crew here.

You’ve tested both side by side? What were they both showing for you?

 

[ecidiego]

You’ve tested both side by side? What were they both showing for you?

I have both. It's hard to catch it since both cycle differently, but I measured 13.8 peak float on CTEK, 13.5 on NOCO. My Odyssey batteries specify that 13.8.

CTEK has a 'Snowflake' mode that gets it this high. Probably designed for cold, but is ideal under any condition for these batteries.

 

[ecidiego]

I'd also consider the peak charge voltage. 14.7 ideally to 'fully charge' a good AGM. This is why the Jeep alternator will never ever charge the batteries to 100%.

 

[ShadowsPapa]

CTEK has a 'Snowflake' mode

Hmmmm, do I say it or just leave it alone............ hmmmmm

I'd also consider the peak charge voltage. 14.7 ideally to 'fully charge' a good AGM. This is why the Jeep alternator will never ever charge the batteries to 100%.

I'd have to look, but I believe my expensive Carlyle battery charger actually has a chart in the book that shows 14.7 as one of the phases of charging.
My 2020 stopped at a high of 14.8
My 2022 stopped at a high of 15.0 (when below 40 degrees)
So far, I've seen 14.8 and 14.9 on my 25
But unless you drive across the country, there's not enough time to complete a full charge, and then it will cut back voltage, sort of defeating the purpose.

 

[spanishmack]

When I changed out both my batteries for Optima's, it took about 2 weeks before my ESS started working again. I didn't sweat it too much at the time, since I can take or leave the ESS, and voltages were all good again after, with no "Aux Switch Disabled" messages.

 

[guarnibl]

I have both. It's hard to catch it since both cycle differently, but I measured 13.8 peak float on CTEK, 13.5 on NOCO. My Odyssey batteries specify that 13.8.

CTEK has a 'Snowflake' mode that gets it this high. Probably designed for cold, but is ideal under any condition for these batteries.

Nice. Thank you.

 

[guarnibl]

When I changed out both my batteries for Optima's, it took about 2 weeks before my ESS started working again. I didn't sweat it too much at the time, since I can take or leave the ESS, and voltages were all good again after, with no "Aux Switch Disabled" messages.

yeah makes sense. I didn’t get the aux switch disabled messages after the battery replacement only noticed the ess not going to ready. But yeah all good now. The main battery I took out dropped down to 12.2 today with nothing connected, it’s toast.

 

[ShadowsPapa]

The main battery I took out dropped down to 12.2 today with nothing connected, it’s toast.

There ya go - you got that figured out. Bummer that it's going to cost a bunch, but you have things nailed down now anyway.

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