Mine's a 451, 3rd Gen I think from 2014.
Hello.I think I have an idea about utilizing an AGM battery. The battery type, doesn't matter, as far as I would understand. But what does matter is the size in Amp Hours. The battery needs to have enough amp hours of energy storage that will allow the car to use an amount of power for accessories, to include the heater while being rejuvenated.
Things needing to know for minimal sizing is; what is the maximum draw for accessories and what is the recharge rate for the battery from alternator and traction battery.
Anyone have that information or any more information to offer concerning sizing the right AGM battery to install?
In the German manual there is a clear statement to pull the service disconnect if you working on the 12V system as otherwise the stored disappearing charge on the 12V network could lead to switch on the contactors of the HV to activate the DCDC converter to charge the disconnected 12 battery. The central gateway controller CEPC is commanding if the KL30 is below 10.5 V to the HV Battery switch on the contactors and dc/dc converter.Hmm. I was digging through the '15 ED manual because someone was concerned about possible slow HV charge rate. The instructions on how to remove and replace the 12 V is in the Owners manual and there is zero mention of removing the service disconnect. There is warning not to leave the HV battery depleted or nearly completely depleted for 14 days or longer or it can be damaged. It also advises against letting it drop below 20% charge before recharging, nor charging at 80% or above...
Well, they don't want you doing and maintenance work or "repair work" yourself either. In other words, they don't want you to do anything. This is jsut lawyers and the marketing division talking."That is for a C451 ED and not C453 I assume?"
Ahhhhh, investigating this comment opens an interesting can of worms.
On p 23 of the 2018 453 EQ manual found online,:
"Always have the following work carried out on your vehicle at a smart center:
You can obtain up-to-date information concerning the servicing of your vehicle at any time from a qualified specialist workshop,e.g. a smart center."
- work relevant to safety
- service and maintenance work
- repair work
- alterations, installation work and modifications
- work on electronic components
- replacing the 12 V battery within the prescribed interval, at the latest every three years.
So they obviously don't want you messing with the 12 v battery yourself.
However, the printed 2017 453 Electric Drive manual, which, curiously, is not available online, does not have that 12 v battery line in the same section on page 23. It was added in 2018.