Battery disconnect question

Ray here...still out there wandering around....

I know it's been asked before but I don't get it...I'm getting ready to swap out batteries in my R3T (Odyssey PC625 for the OEM battery). On a previous post here I read that if you disconnect the battery the computer will keep the tune but lose the odometer....is that true?... all of the odometer readings? ....including the overall milage on the bike?
Somehow I just can't imagine losing the overall odometer reading...you can see the implications here.

Just looking for clarifications here and any OBTW's (Oh-By-The-Way's).

Thanks
Wandering guy here in Louisana I think...(at least they're selling croc-a-gator heads and stuff in the gas stations!. Way cool.

It may wipe the trip odometers out but not the bikes mileage.

It might wipe the variables from the ECM, like O2 reading, but not the programed tune.
If it should run rough or not idle properly after a battery replacement, a 12 min tune will restore those parameters.

Now on the off chance the ECM internal power supply is bad, there is the chance other things could be lost, it's just not likely.

If it worries you that there is a 1:10,000 chance something like that could happen, there is a way to guarantee that it doesn't. You can simply take a 9v battery and use clip on leads to the positive and negative battery cables prior to taking them off the battery. Leave the 9v connected until the new battery is in place and the cables are re-secured.
The 9v battery trick was used by GM techs to keep some late 80's and early 90's Chevrolet cars/trucks from loosing idle parameters when replacing the battery.

I've never lost anything on my bike when the battery was disconnected, but I have heard of others complain they did.

Thanks Hellfire...appreciate that...the nine volt deal sounds sensible. I just couldn't imagine losing the overall bike milage...in my state (Wash) that would be totally illegal....and for those of us old enough to remember...the roll-back milage thing was one of the biggest issues in car buying for years.

The tune on my bike is good...the bike runs awesome...just that the battery keeps conking out when it gets below 40F degrees (4C for Eurospeak )...and with this cold snap...looks like 40's is going to be the high for a couple of days. I went down and bought the Odyssey but haven't installed it yet...I guess I need to get a bigger hammer first ....(way too busy running around and all that stuff). Anyway, I guess I could just use the new battery as a jump starter until I can change it over....sometimes I miss the old days before electronic ignition and digital odometers.

Thanks again
Wandering guy out.

You will need the Odyssey charger for that battery. Standard chargers don't work well on it. The Glass Mat Lead Acid batteries need a higher voltage and specific Time/Voltage algorithm. I hope you picked up one of those too.

I have never heard of a bike or car losing the miles reading with changing the battery I have installed more batteries than I care to remember and NEVER had a problem.

battery swap

Hi Ray
Let us know how you get on with your battery swap. Without majot surgery to battery box i cannot see how i could get an Odyssey PC 625 into my R3T.

Regards Mike

There was at least one guy who was complaining that when he reset his trip mileage, his odometer reset back to zero as well. He may have been confused about the two trip indicators, I don't know. But there was also another who said his odometer reset when he changed his battery, I've never heard of that kind of thing happening confirmed either.
However, it's very possible that the info gathered during the 12 minute tune could be lost. But that would be re-established just from riding it or doing the 12min again.

General motors early OBDII's, particularly in the V-6 Cavalier and Beretta, would forget how to idle when the battery was disconnected. You would have to sit with your foot on the accelerator for about 15 minutes before it would re-learn how. GM issued a special tool to prevent the wasted time during a battery change, it was a 9V battery connected to a cigarette lighter plug (very high tech). You plugged it into the lighter before disconnecting the battery and it was supposed to power the memory in the ECM. Trouble was, if you know how unreliable those cheap plugs are ... they didn't work all the time because they came loose. So Tech's made their own with alligator clips so they could clip it right on the battery cables.

Once in a great while on even the best cars, unhooking the battery can cause something to malfunction. It could be a line of programming missed when it re-boots, who knows ... but hooking up that little 9v battery was cheap insurance.

My wife's Benz had the battery replaced at the dealer because they were running a special that was only $25 more than what I could have put an aftermarket in myself. When she got it home she told me the climate control didn't work afterward, so after *****ing to myself "why didn't she tell this to the service advisor while she was there", I unhooked the battery, waited 10 minutes, and slapped it back on quickly so there wouldn't be any power spikes. Everything worked fine after that, if you jiggle the post clamp on cars like Mercedes things sometimes don't boot up right. I think that will become more common as regular cars/and bikes get more complicated. A 9V battery would have kept that from happening.

It's one of those things that isn't supposed to happen, seldom does, but could.

mklambe said:

Hi Ray
Let us know how you get on with your battery swap. Without majot surgery to battery box i cannot see how i could get an Odyssey PC 625 into my R3T.

Regards Mike

Click to expand...

The modification to the box is easy ... bend the lip over with a hammer.

Getting the box out is the hassle. I imagine the first stage on the assembly line is when the battery box is placed on the floor.

There have been some who cheated and cut the cooling fins off the side of the battery.

Your odometer mileage will not reset. Just the trip meters and the clock. I have disconnected my battery on the R3T many times with no issues. No problems with the tune or running differently. If something goes wrong there is a reason. Dont ground the battery to the frame with a tool (touching the + terminal) or anything like that and you will be fine.........................is it done yet?............................now?.................hurry up we havent got all day to troll this thread yknow

mutt

Oka'y so I'm at a campground in Nowhere Swamp Louisiana...they have killer racoons here...and croc-a-gators and other molesting creatures so it's difficult to focus on changing the battery out when you're being attacked all the time...besides...my only tools are a hachet and hammer...now what do I have to do to modify the battery box? I figure I could just take the hachet and trim the fins on the battery (probably better than beating down inside the thing. I almost got it done but I think it would have been easier if I would have removed the seat first .

Actually, I'm going to wait until tomorrow when I have some light and it's not 40 below.

Thanks for all the help guys...I have faith now I can make it work...whether it wants to or not!