Changing Mitsi Batteries

I have a A2USHcpu-S1. I have searched other forums and Mitsubishi on how to change the battery. Mitsi website only has the conversion from a A6-Bat to an A8-Bat module or I may not be looking in the right place. I tried the downloads section.
The question is can I change this A6-Bat with a new one while the plc is powered up? Also when I do change the battery will the fault LED go away magically or will I have to reset the cpu?
Production is running and so no interuptions is what I'm looking for.

Thank you

I have changed batteries under power before, so I don't see a problem with that. I have never found a way to clear the err led w/o doing a reset, however. It's not that way with the QCPU, which has a published method of resetting the led through the code

Thanks SteinCollector. I actually did a hot swap of the battery and did indeed have to reset the error led w/o incident.

I appreciate your response.

Yep I allwasy change them while powered, again this is because our processes never stop but there is no problem powering them down as I have had processors hold memory for days before although they recommend only 10 mins.

On the old A series had a processor that held it for over a week (someone had put a password in it).
in reality it took two weeks as on the first week I poered it up a couple of times & of course this charges the caps up again.

As I said on www.mrplc.com, be careful switching them under power, because there is a battery error bit which can be called from within the PLC program, so who knows how the program will respond when you pull the battery.

Mitsubishi manuals clearly state to power off the PLC after it has been on for a while to charge the capacitor backup, change the battery within 5 minutes, and power it back up.

Thanks Crossbow. I don't have very good luck manuvering around on meau.com. I wish I had the manuals. I will remember to not do that in the future.

MEAU.Com is pretty easy. Go to Downloads, pick Manuals, and then you have your choice to search by hierarchy, part number, or manual number. It's pretty straightforward. They also sell the MELDOC-DVD which has all the manuals and CAD drawings. I've got one I keep in my laptop bag.

Thanks. I'll check into that. I appreciate your help.

Hmm.. If the battery is almost flat then the error bit will already be on? so if some code is tied to it then what's the problem, what fool would write code that did some damage if the error bit was on.

You would be amazed Parky often its a programmer that is in a rush project that simply overlooks his fault routines. Come across that one in every 5 machines on average

I have seen programs where a low battery warning starts and automatic shut-down of the machine. In one case, it was a stone quarry, and so conveyors would start to shut off if you pulled the battery while running.

And I've seen hundreds of programs with no code on the low battery warning.

So there's 2 extremes.

Hold on, no code for battery warning still no problem, plc ok while powered up but loose power & no program plc will go into stop mode.

So what if the batt low warning stops conveyors etc. at least it makes you look for a problem (and even maybe you notice battery is flat before you pull the power & loose everything).

come on guys, plc's have been developed to shut down in the event of corrupted code or loss of I/O, lots of plc engineers decide to turn off I/O checking etc this can be dangerous only idiots write code that could cause damage to plant or even worse injure somebody.
I've been in this game for over 25 years & seen a lot of code, some good, some bad & some very bad. anyway the original post was about a plc keep shutting down & battery replacement be it live or powered down, if the battery was flat then the error bit would be on, if not then why change the battery?.
Also if you intend to replace battery live then switch it to stop mode, at least you can then be sure no code will run until your ready and not pre-occupied.