Hello,
Has anybody any experience with using the ctek multi us 3300 in power supply mode to maintain electronics/electrical current while replacing the battery?
The manual PDF I had wouldn't mention anything about that.
Any advice on how to do that?
Thanks many times.

 

I thought only the Multi US 7002 had that feature.

 

That's actually what I'm asking, can the ctek 3300 do power supplying while replacing the battery?
Thanks

 

Probably not. Just went out and put a voltmeter across mine (no load voltage) and it has no output for any mode with zero current (zero volts). So, for a given finite current, there will be a drive voltage. It is quite likely that it will interpret a small current (quiescent current during replacement) as an excuse to vary the current/voltage to desulphate (or something). I wouldn't do it.

If you want to do this, find a pair of appropriately sized wires or jumper cables and bridge from old to new while you are replacing.

Note added: Of course, presumably you are replacing the old battery because it sucks, so are you sure you don't want to reset?

 

Yes, replacement of old battery. I could reset I guess, but I thought it would be less troubles doing a 'live' switch.
thanks

 

How would you bridge the new battery? Positive pole to positive cable and negative to negative pole, right? Or in reverse order maybe? Also, is that bad to have 2 batteries connected at the same time?

 

Yes, same orientation, connect the new battery positive and negative terminals with the jumper cables to the corresponding positive and negative cables (not the terminals). Having two batteries in parallel will not cause drama for a few minutes (just like you were jumping a car) unless the original is shorted, in which case, you wouldn't be doing this anyway because the old battery would be providing no voltage.

With my jumpers, I could potentially keep the lower part of the terminal connected while mounting the battery cables. So, there's a tricky maneuver to 1. disconnect the cables from the old battery terminals while keeping the jumpers connected to the cables (easy), 2. move the old battery out of the way (more difficult to keep everything connected), 3. reconnect the battery cables to the new battery terminals while not dislodging the jumpers until you make electrical contact (much more difficult), If you had a second set of cables, at this point you could connect the old battery back to the battery cables to provide voltage support. 5. disconnect the jumper cables.

All theory, of course, since I've never done this. And there are other ways to do this (for example, I have a power supply that would suffice or some other cabling scheme), but I'd simply reset. I like driving it anyway, under ten minutes to teach it idle and reset the windows, and and it always gives me an excuse to zoom down the motorway and cruise around the neighborhood giving it the 'varied' conditions it needs, or that's what I tell my wife.

 

I am curious why it would be important to maintain power. I never have in the past and have had zero issues as a result.

 

there are inexpensive adapters that can be used to power the car through the OBDII connector. some in areas with emissions testing find this a good option as readiness codes and adaptations are not lost with a battery change.

 

If this is such a major problem.... Couldn’t you just run the car, take out old battery, with engine running, and put the new battery in.

Alternatively, with engine off, why not plug in any battery to the connections under the bonnet, and then swap in a new battery in the trunk?

 

Don't do the former! The car needs the battery to smooth out voltage spikes / provide a load for the alternator.

 

I keep seeing those gizmos that you plug into the cigarette lighter that are supposed to maintain settings when a battery is removed. Do those actually work and serve that purpose?

Doug

 

I didn't know they had it. That definitely would facilite the switch. But are cigarette lighters live on these cars with ignition off? It's for a 04 xkr btw.

Thanks for all your help btw, really appreciate.

 

My 2009 XF is giving me hell with this parasitic draw.

It was diagnosed by the dealer a few years back as a faulty battery. They were wrong - though the battery was shorted due to the constant dying-recharging scenario. Like many Jags, my cell phone interface was faulty but the car would search for the phone. I tried to disable this from the software, but probably to no avail.

Over the years, I have parked my car and thought everything was powered down, only to go for a walk and as I passed my car on my driveway, I noticed a light on....it was the touchscreen, and the computer system was clearly on, doing God knows what! (Draining the battery.)

The relay from my hood latch is faulty, which though latched - it sends a warning light that it is not latched. A far more brilliant mechanic (than wannabe mechanic me) has noted this could be one of the parasitic origins. Anyway, the charging and recharging demands fried my alternator - which I had replaced (FYI: tough reinstall of this part) - but this may occur again.

I'm tempted to put a trickle charger on it for the time being (the brilliant mechanic can't take my car for a month) but this is only a temporary bandage and no cure for the problem.

It will take some time to analyze the cause of the parasite. Until then, I would like to disable the boot(hood) relay, the cell phone - whatever else. The cell phone is particularly troubling, but its under the seat and I don't want to remove that seat due to fears it won't go back in the same way as it came out.

Electrical parasitic draws are a big problem inherent to the design. If anyone has a simpler solution, I would be grateful to hear what you think. (Just put another new battery in!)