BMW R1200RT/R1250RT Forum

Yes thanks but I'm not sure the AGM battery for the RT requires the Odyssey setting. The setting has the effect of raising the charge voltage to 14.7v from the normal 14.4v but there's no indication on the battery or the manual that that this is required for the BM. Anyway I've stuck with the normal setting.

Better to be safe with a charge voltage of 14.4V, rather than sorry with 14.7V.

Have found a CTEK Charger manual, http://www.ctek.com/Archive/ProductManu ... 5.0_EN.pdf

The "Car Setting" is Normal battery program 14.4V/5A Use for WET batteries, Ca/Ca, MF, GEL batteries and many AGM batteries.

The "AGM Setting" is AGM option 14.7V/5A Use for charging most AGM batteries like Optima and Odyssey.

This confirms that the "Car Setting" does include AGM Batteries, like the one fitted to the RT LC.

Do these readings clear anything up. Showing on a BMW charger 10 minutes after being connected to the bike which hasn't been on charge for 3 weeks.

Yes thanks, confirms that the BMW Charger kicks out 14.4V for an RT LC OEM Battery when fully charged.

My understanding is that, the likes of Optima & Odyssey Batteries are branded & sold as having higher cranking amps and additional reserve capacity as compared to the stock battery.

To achieve this in a fully charged state, a higher (14.7V) charging voltage is required.

The Odyssey PC680 is the pre-LC R1200RT OEM replacement, https://www.batterystuff.com/powersport ... PC680.html

Yes, thanks to all, this confirms my earlier view that the RT LC battery, although AGM, differs from the Odyssey type that CTEK mention in their manual which require 14.7v so I've been right to stick with the normal setting at 14.4v. I've never used the higher setting for any bike or car since none had Odyssey type batteries.

Incidentally, the higher voltage setting shows on the device as a snowflake, indicating that it is meant primarily for very cold weather on any battery, not just the Odyssey type. It's only when you read the instructions that it states that that this is also meant for Odyssey types. The CTEKs are designed in Sweden where it can get very cold for long periods but that would not apply where I live, (south east England) so I have no need to use the higher voltage for that reason.

This is the current version of the model I have. Previously I used Optimate but when my last one finally gave up after many years, for no particular reason I changed to CTEK instead of the latest Optimate.

http://www.ctekdepot.co.uk/12-volt-char ... duct_id=52