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I would like to install a kill switch somewhere in or on the vehicle to interrupt the ground cable. It might be the hot side, but my friend suggested it is the ground cable.

Our Rav sits for long periods and it is hard on the battery, so I use a charger on a timer that goes an hour a day, to top it off. I would prefer to use it with the system disengaged, because I have heard that it can damage the alternator.

I think I recall that some systems reset themselves when the batt is disconnected and I am not concerned about the clock.

So I would like to install a night switch similar to what large trucks use or like an aircraft master switch or a motorcycle or skidoo kill switch.

A friend had one on his antique car. Great for antitheft also.

I see night switches at Battery Disconnect Switches - Electro-Wizard Automatic Battery Disconnect Switch - Combination Battery & Alternator Kill Switch - Combination Magneto & Battery Kill Switch but I figured there are some pretty smart PPL here who might know better.

Is it worthwhile?
Is my thinking right on pos/neg and
does the charger hurt the alternator?
 

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Well, I guess a switch would be one way to do it. I'd just pop the neg battery terminal off. I use a small battery maintainer.
 

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Well, I guess a switch would be one way to do it. I'd just pop the neg battery terminal off. I use a small battery maintainer.
If you are worried and absolutely want the battery disconnected then I would do as ravenuer indicated. That being said and to answer the next question, no the battery charger will not hurt the alternator.

This is probably the misunderstanding on the alternator. When boosting someone, the boosted vehicle uses the power from your vehicle. If they try and start their vehicle when yours is still running then there is a possibility of a voltage spike when their charging system kicks in and could fry a circuit board on your alternator. The way to make sure this does not happen is to turn your vehicle off prior to them trying to start theirs. As normal, your would keep your vehicle running while trying to charge their battery but then shut it off and with the cables still connected (still using your battery to help their vehicle start) they try their vehicle.

As long as the vehicle is off (like when charging your battery) you will not get the voltage spike back in the alternator.
 

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I would use a battery float charger since they monitor battery voltage and switch on and off, and is closely regulated to maintain the battery charge, rather than the sort of maintainer which outputs electrical current at a constant rate. The latter could damage the battery by overcharging while a good float charger will not. Disconnecting the negative cable will cause the vehicle system to lose its memory which will affect everything from how the vehicle runs when the electrical current is restored to radio presets. Antique cars did not have the systems which would be impacted by disconnecting the battery.
 

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Blogson.
Do you have a link to a good 'float charger'?
This sounds like something I'm looking for, to hook up to my garden tractor (housed in an outside shed with electricity, but no heat) between November and April.
Yep. 6 months of winter, but not this year, I think.
2 seasons here: hockey season, and road construction season.
 

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Everybody else has pretty much covered all of the reason why you shouldn't(or don't need to) try this.
I'll touch on a couple of more.

A properly connected battery charger, that is rated for auto batteries will not hurt your alternator one bit. This might be a misunderstanding about battery charging. USING your alternator to try to charge a completely dead battery is a bad idea. It puts a lot of strain on the alternator and definitely shortens its life.

Killing all the power to a modern vehicle will erase everything the ECU and transmission controller have learned and make them start all over, this will mean poor gas mileage and rough shifts every time you reconnect and start your car until everything is "learned" again.

Interrupting the ground circuit could cause other unwanted effects, you'll introduce some resistance into the ground circuit that, if it were to increase, could eventually cause damage to the vehicle's electronics. I wouldn't ever want to introduce something into a good chassis ground.

Rick
 
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dave_d: This link is to one supplier's float chargers. Even though the descriptions refer to use for SLA (sealed lead-acid) use they also are suitable for unsealed batteries. SLA Battery Chargers Types and Instructions Of course they are U.S. based and I don't know about exporting to Canada, but they may do so and probably even have a Canadian distributor.

Edit: A link to a distributor for Canada: http://ca.mouser.com/powersonic/

About lawn tractor batteries during winter season (rain here, rather than hockey!) I simply use a regular automotive battery type charger and every month or so connect the charger at 2 amps until the battery is completely charged. It must be working properly since the Walmart Everstart battery in our lawn tractor was manufactured in June of 2006 and is still working great.
 
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You can buy a black & decker float/trickle charger at Walmart. Just look in the automotive section. About $25 or so. Does a great job. It comes with both clamps or spade lugs for permanent installation.
 

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You can buy a black & decker float/trickle charger at Walmart. Just look in the automotive section. About $25 or so. Does a great job. It comes with both clamps or spade lugs for permanent installation.

This Schumacher offering from Walmart is billed also as a float charger, so it may do the job. I have one of these but use it only for charging my motorcycle battery if the bike hasn't been ridden for two weeks or so, and then disconnect it. Have not used it as a float charger so I don't know whether it actually works as advertised. Having tested a few similar items which were advertised as float chargers some output a constant electrical charge, which would be bad for many lead-acid batteries. Schumacher Automotive SpeedCharge Battery Maintainer and Charger - Walmart.com

From experience I have reservations about any Black and Decker charger which is advertised as a float charger.
 
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Thank you, guys.
My problem is that I can't get into my storage shed during the winter, because the door becomes frozen shut.
So I am looking for a charger I can connect in November and disconnect in March/April. Previously I have disconnected the battery and brought it into the house for the winter, but that is a PITA.
 

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dave_d - the Schumacher 1.5 amp charger noted in my previous post (#11) should do the job for your lawn tractor battery. It is supposed to have float charging capability, and although I haven't tested it extensively I have connected it to my motorcycle battery and kept an eye on it for a couple of hours, and it does what a float charger should do. It switches on and off after the battery has been fully charged and maintains the battery charge but does not charge constantly. If it were to charge constantly it could damage the battery.
 

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Thank you.
I just ordered it from Amazon.ca.
$51 !!!
 

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We're Canadians. We're used to it.
You won't be seeing as many of us this winter.
Our dollar is now worth $0.71 US.
On a GOOD day!
 

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Looks like it's a good time for us to take another holiday in Canada!:wink
 

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We're Canadians. We're used to it.
You won't be seeing as many of us this winter.
Our dollar is now worth $0.71 US.
On a GOOD day!
Now I understand why so many Canadian women of the night cross the border.
.
 
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