tjkj2002 wrote:
Never unhook the battery while the modern vehicle is running,even in a modern diesel.That is the sure fire way to fry the PCM.Plus a gas KJ will shut off if you disconnect the battery while it is running,I imagine the CRD will also since the voltage regulator is not in the alternator.
After adding a winch and actually use it often you will understand the need for those high priced batteries like a Odyessy,plus with a AGM battery no more science project will grow on your battery terminals like old school lead acid batteries.Also my 2 year old Odyessy still puts out over 1300cca's while only being rated at 880cca's.
Ok... The alternator will provide plenty of power, the voltage regulator turns that power down from high voltages to the 13-14 that a charging battery and the vehicle's systems desire.
Tell me again why the AVR would get upset if the battery was disconnected? It doesn't change the duty by changing the location of the AVR, and the AVR also has to provide power to the ECM and the rest of the car's systems. If it isn't being asked to provide charging amps to the battery, the overall power draw goes down, but not to zero. Disconnecting the battery is the fastest way to verify that your alternator is providing good power - If the engine speed dips or stalls out, then the alt wasn't providing enough energy and should be replaced at some point. This isn't a nanny function, its how cars actually work. The engine speed shouldn't change at all when disconnecting a battery, except maybe to momentarily increase as the power load decreases.
You really should base your opinions on factual experience, not the ramblings of that bearded old mechanic at FailureStone who hasn't touched a car in years. I've swapped out the battery in my KJ CRD (and just about every other vehicle I own or owned) with the engine running without any problems. The CRD doesn't "shut down" and neither did any of the others. The ONLY way that you would cause a hazard to the ECM or any other systems is if you let the positive terminal touch a ground source like the body or engine. This would short out anything connected through the charging circuits, which is why I do not like the design of our AVR. Replaceable components are better, as what happens if a battery fails internally and shorts a plate? Same result, and it could happen to anyone at any time due to a manufacturing defect.
Simply unhooking the battery and protecting that positive cable from touching anything won't hurt anything. A manufacturer even sells a portable battery device that you connect to your car to put power INTO the cables (with the engine off) to retain settings while swapping batteries. This is equally dangerous, for the same reason - Let that positive cable ground, and boom. Simple free solution: Don't let the positive cable ground if there is power in it, and nothing bad will happen.
Finally... Higher price or AGM does not equal better performance driving a winch. The battery contains a certain number of amps to deliver. Maybe your 1300ca battery just is one of the better-built of that model, and their rating of 880 is a manufacturer's-middle-range rating. Some might make less, some like yours might make more. That changes nothing for driving accessories. Either the battery can deliver the amps requested or it can't. If it can't, you need a bigger battery for the job. Science projects... Thats funny, I do like that. Honestly tho, not one of my maintenance-batteries from Costco has had the green grass problems on the terminals.