pros and cons of installing a 2nd car battery?

Old 06-28-14, 06:12 AM
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pros and cons of installing a 2nd car battery?

So I'm thinking about installing a 2nd car battery (in the trunk) because
I don't drive long distances daily and my 2-channel car cam seems to stop recording some days due to low voltage (it has automatic shutdown when it detects the car battery is getting low to not drain it and leave enough power for startup). Mine is a chevrolet spark 2011.

I'm hoping that a 2nd car battery will allow me to run things like car cams and
maybe some LED lights while car is off and parked.

I've never done this before, don't know much about batteries, so it would be helpful if anyone can mention what some pros and cons about doing this are. I'm only looking for about a 45 AH battery or so as the 2nd battery.

Not sure if I'm accurate on the pros and cons but here are some that I think may be relevant:
Cons: extra weight (30-40 pounds?), maybe more stress on the alternator?

Pros: having more power to run equipment off of while car is parked and off, so as to not kill the main battery.
Old 06-28-14, 06:28 AM
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Trucks with campers and RVs do it all the time. Usually, they'll have a switch to isolate the extra battery so if it runs down the main battery is still charged and can start the vehicle. I wouldn't be concerned with the extra weight. I don't know if it's harder on the alternator.
Old 06-28-14, 07:54 AM
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You should look into a small deep cycle battery. As long as you don't keep discharging that battery real low your alternator should handle it fine.

I would recommend using an isolation relay as opposed to a charge isolator block. When you're ready I can give you specifics on the relay.

You would need to run a cable from the front battery to your rear battery. I use #4 for most of my generic dual battery systems but you can use smaller. You would install a fuse at the main battery and at the aux battery to protect the wiring against shorts. The isolator relay goes under the hood and is activated only when the key is in the run position.

I have three batteries in my work van.
Old 06-28-14, 08:13 AM
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Like PJ said. deep cycle batteries is your ticket. Optima brand is likely the best, but it'll cost you pretty pennie.
But why? Get a solar charged battery tender and simply have it connected. Or, should you park inside and solar is not feasible, simply any battery tender. Much cheaper than battery.
You MUST clean your battery terminals and cables and lubricate and seal them. Dinky little LEDs and car cam should not drain your battery at all. Not sure, btw, why your car cam is running with car shut down. I have 2 of those, and they both shut down minute or so after car is shut down. They both have G-sensors to turn on when vehicle is shaken, for security purpose, so they are in stand by, but stand by is off built in LiI battery.
I'd say, instead of entire project running you several hundred bucks and major electrical work, simply clean everything, and replace your car battery with quality deep cycle one. Will last and last.
Old 06-28-14, 08:39 AM
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Wasn't this question discussed and answered before? In the alarms section?
Old 06-28-14, 09:19 AM
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Old 06-29-14, 05:22 PM
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Sorry, I think it may have been overlapped. Most of what I've been asking is related to one another so maybe I've been asking similar questions, just from a different angle. "The quality of your answers is based on the quality of your questions" ....

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