AGM battery for Gen 4/Gen 5 Prius/Prius Prime and observations on the 12-V charging system

I never stated what my flood cell batteries SOC is. Where did you get that statement from ?

From the data you have already posted :

As you can see, your AGM 'rested battery open circuit voltage' (as you describe it) has been trending downward from 13.05v on day 18 to 12.82v on day 13. That demonstrated a downward trend in 'rested battery open circuit voltage'. If you continue to monitor this 'rested battery open circuit voltage' I am speculating that it will continue to trend downward if you do not put the car in ready mode. If it levels off at some point before you decide to recharge the battery to 100% SOC with an AC automatic AGM profile charger the downward trend will start off anew. Hopefully you will perform that task at a voltage of 12.3v or greater.

Note: You are not measuring and recording a 'rested battery open circuit voltage' technically. You are recording a rested battery voltage with parasitic load. This is not an open circuit voltage, the battery is still hooked up to the Prius.

If you would like to accelerate the downward trend in your AGM you could just continue to let the battery rest, still hooked up to the Prius, for several days, maybe a week or so, and watch the battery voltage continue in its voltage downward trend. Please do recharge it with an AC charger before it goes down to 12.3v or less.

I will post some data from the new flood lead acid in my Prius soon.

Yes, AGM batteries have superior performance compared to flood lead acid batteries. But both batteries need to be charged to 100% SOC regularly or they will suffer a shortened life.

 

Do you have an app or program (excel ?) that produces a graph like that from the date/time data and the battery voltage data ? I've been looking for one, No success yet.

 

Just replaced our 7¾-year-old OEM AGM in the 2018 plug-in minivan (manufactured September 2017. LoL - ZEEEZ the stock 12v with its 650 cold cranking amps & its replacement according to Costco needs to be 750? Who writes these nonsensical & almost stupid suggestions ?!? All it needs to do for the next 7yrs is wake the freaking ECU that tells the relays to open. Obviously - even in our environment where it sometimes hits as low as -30°f for few morning hours - the 12V AGM is going to last more than the 7 years that WE got out of the OEM. Seems the best way to test a hybrid 12v is to occasionally leave the ignition on for a few minutes, have the headlights & sterio & heater fan on to see if it pulls down quickly. Ours still didn't - for well after it's recommended 6 yrs. But airing on the side of caution, we replaced it due to its age.
STUPID thing was, the vent tube insert hole meant the fiberglass strap running across the top of the 12 v would block inserting the plastic vent tea. Oh well, Costco's $175/3yr warranty beats Chrysler's $600 obscene price by a mile. No wonder the poor slobs at stalantis are in the red.
If Toyota ever puts a plug in their minivan, we will be all over it.

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Simple. Costco's warranty, price & convenience.

 

Between Bezos' leftist woke agenda, & Costco giving a $15 core return?
Easy decision. Out the door $170 & $15 for returned core

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You can find most of the same Chinese junk Amazon sells Via TeeMu - so why does anyone need to enrich someone 3rd party enriching products from china.... see post #71 for price info.
For streaming we typically use netflix & dish/Samsung.

 

LOL stated that way it sounds like you wrongly believe you need to goad to me into confirming a size so you can assure YOU have the best deal? LOL is there some kind of misconstrued theme that I'm keeping a secret? No ... we required H6 or H7 (h6 was less) for it to fit in the Chrysler compartment which is in the rear left cabin wall. By hooking up the +/- leads to a battery charger we were able to maintain lots of personal settings which meant we (i) didn't have to spend an hour reprogramming tons of junk (seat settings - prior mpg, satelite & terrestrial radio etc) .

 

So that's the long-winded version to say the costco/interstate H6 ain't too bad. Coupled with all of the other pluses & considerations mentioned above, that makes it even LESS of a 'not too bad' - right? Especially considering Amazon's 30-day warranty policy.
Even that is very shaky. We ordered 1,000s of dollars of folding chairs for our church camp ground & Amazon REFUSED to pick them up (costly) so we could get a refund once they started breaking apart & the upholstery started cracking apart some 2 weeks after delivery. Costco has never been tight fisted regarding warranties. Dear amazon, BLANK you.
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I wouldn’t leave it in reverse unattended either. Have you priced those back up lights? Going to be $1000+ and have to remove the rear bumper.