adding batteries

[Jason Young]

This may be a stupied question , but I have bought a 98 blazer that I am going to use for next year ( better on gas than my GMC 1500 ) . I am going to add a battery in the back to power my 4 radios and a 750 watt inverter .
How do you tie the two batter's together so that the second one can charge ? Thank's

 

[Darren Addy]

A battery in a vehicle doesn't really run your radio or your power inverter (unless the engine is off). All the battery REALLY does is provide the juice to turn the starter and get the engine started. After that, the juice for your headlights, your heater/AC fan, your accessories (etc.) comes from the alternator. You might look into the output of your alternator and consider getting a higher-capacity alternator, and you might want to wire up some additional cig. lighters for your power inverter (etc.) but I don't think a 2nd car battery is necessary (or a very good idea).

Others with more experience will (no doubt) chime in.

 

[Jason Young]

Yes that is a good piont . I keep running my battery down in the last car I used while i was parked and had my ham and inverter ( laptop ) going . I have a bad habit of showing way to early and thinking of more a safe guard for this year.

 

[Jim Saueressig]

I always did 2 batteries one on each side by adding an additional battery tray opposite of the original and stringing the cables across Positive to Positive (or you will double your voltage and kill equipment), negatives to ground. I am not sure what all would be in the way on the opposite side of the original battery on newer vehicles though. Just keep it under the hood if possible and matching amp battery pairs are the only way to go IMO.

Make sure the batteries are tied down and the cable cannot be pinched or rubbed through and a quick disconnect on the cable out to the second battery from the first is also a great idea. This way you double your battery use time with no other cable to equipment modifications.

Some people will choose to hook up their equipment to the second battery only and turn the disconnect off when the vehicle is not running so that it will only drain the second battery and leave the first to start the vehicle, this however requires you to do a lot of switching on the disconnect over time and is hard on the second battery. I know you used to be able to get a device to shut off equipment if batteries were getting near the point of no restart but it's slipping my mind this late at night what it is called. The first idea is the best all around option.....

 

[Tyler Allison]

I run dual batteries with a Hellroaring Battery Isolator/Combiner /w remote module

BIC-95150B

I will never run my car again without it. It has saved my bacon from a dead battery twice since I installed it. I can now turn my car off and run all my gear and be sure that the car will restart when I need to get to a safer place.

My second battery is an Optima Yellowtop (not spillable) in the back of my Subaru Outback. Full break down of the power hookup:

.....Hellroaring Battery Isolator/Combiner+Remote Module [ BIC-95150B ]
…….Optima Yellow Top D34 Auxilary Battery
…….Stinger SBTM Battery Terminals (1×0g,1×4g,2×8g)
…….Stinger 4 Gauge Pro Series power wire
…….Stinger 4/8 Gauge Inline AGU Fuse Holder
…….800Watt DC-AC Inverter

 

[John Erwin]

I run dual batteries with a Hellroaring Battery Isolator/Combiner /w remote module

I run an almost identical setup and agree with Tyler's sentiments. This is an excellent setup for those who need to power their equipment when the car is not running.

In my case though I also elected to upgrade the alternator (I purchased a high output model from Mean Green for my '96 Jeep Grand Cherokee). This really is the best option for high-current needs when the car is running to insure your battery(s) are not being depleted when they should be getting charged.

If you install a battery in the passenger compartment make sure it's a sealed type (ie the Optima type that Tyler mentioned) since they will not vent hydrogen gas into the compartment.. a really bad thing. Also make sure it's tightly strapped down since you don't need a heavy projectile like that flying around in a crash.

I do not recommend simply wiring in a second battery in parallel with the current battery; even if the batteries are matched reasonably well charging problems are highly possible, especially if you elect to also use a switch or relay to isolate the second battery for non-engine running use. Best to use a quality battery isolator since this will manage the charging/use of the second battery.

 

[Gene Moore]

If you have too much equipment for one battery a second one is a good move. You've already had some recommendations, I'll add that any high quality "marine deep cycle" battery will do fine, they will last much longer than a typical starter battery and can be bought at WalMart or Autozone. I like Autozone (if they still carry them) because they've replaced two of my batteries free.

Also you should buy a device that will isolate the second battery from the charger battery. Thus, both will charge but if the equipment battery runs down it won't drain the main battery for starting the vehicle, very important! These devices are not too expensive; I think I paid about $45 for it 4-5 years ago at NAPA Automotive. Also, just an opinion, I would not put the second battery in the vehicle passenger area, keep it under the hood. If you have an accident or worse a rollover you'll regret

having a battery in there with you. You can keep it under the hood and bring #10 or heavier wire into the vehicle.

 

[Tyler Allison]

Also, just an opinion, I would not put the second battery in the vehicle passenger area, keep it under the hood. If you have an accident or worse a rollover you'll regret

having a battery in there with you. You can keep it under the hood and bring #10 or heavier wire into the vehicle.

I completely agree. Unfortunately in my case, the Subaru outback does not have enough room for a second battery in the front, and it doesn't have a trunk

 

[Brandon Sullivan]

I have a Heavy Duty 160 Amp Alternator, 1000 Amp Deep Cycle Battery. And it is nothing to run my equipment all night.

I do recommend getting a ChargeGaurd or Battery Buddy. These will shut off your equipment when your battery gets low, leaving you with enough to start your car.. And, the chargegaurd will turn on your equipment when you start your car.

But Sounds like Tyler And John have some pretty sweet setups, so you could try whatever they do as well.

 

[Joey Ketcham]

I don’t mean to burst anyone’s bubble, but why would anyone want to place themselves in an enclosed area with a car battery? It is very stupid to do and places all occupants of the vehicle in danger.

Car batteries are full of sulfuric acid which releases clear, colorless and odorless fumes which are very toxic and you will be breathing these fumes in without even knowing. Sulfuric acid is also corrosive and can become airborne as small droplets or can attach to other small particles in the air which you will eventually inhale. Car batteries can also leak and if you come into contact with the sulfuric acid it can cause severe chemical burns if not washed off immediately, may not be very fun if for some reason you come into contact with the sulfuric acid from the battery when out in the middle of BFE Kansas surrounded by nothing but open fields with no place to immediately go to so that you can wash your hands off.

Aside from the fumes, you also have the risk of having the battery explode. When concentrated sulfuric acid is mixed with water the solution becomes very hot and can catch fire or explode by coming into contact with other chemicals or metals. And just in general you have the risk of having a car battery explode or catch fire. Also if you are a smoker you risk having a car battery explode or catch fire by smoking around it. My dad is an automotive tech and has been for over 35 years and he has many horror stories of car batteries catching fire or exploding, he knows people who were seriously injured by having a car battery explode or catch fire.

If you want an electrical system inside your vehicle to power up your equipment either have an automotive tech do so for you, or someone else that is good with electrical systems. Placing a car battery inside the vehicle with no protection between you and the battery is not the right way of doing it and will only be placing you and all other occupants in unnecessary risk. It is only going to be a matter of time before someone has a battery catch fire or explode during the middle of a chase.

There is a wealth of information if you do a google search about the dangers of car batteries. I'm surprised that so many people are quick to put car batteries inside their vehicles without even thinking about the risks and dangers involved, there are other ways to achieve getting power to your equipment without having to put a car battery inside the vehicle. Luckily for me my dad is an automotive tech and he helped me get my vehicle setup so that I could power up all my equipment safely and it has worked well for me over the last couple of years.

 

[Tyler Allison]

Not all car batteries are created equal. Much like some people are comfortable being 100 yards from a tornado, some are not. It's a mater of risk tolerance. Generally speaking I would agree...but it's not a black and white decision.

If you are that concerned, you can purchase and install a Moroso 74050 sealed battery box. It's NHRA approved for installation inside the driver compartment.

 

[Joey Ketcham]

Not all car batteries are created equal. Much like some people are comfortable being 100 yards from a tornado, some are not. It's a mater of risk tolerance. Generally speaking I would agree...but it's not a black and white decision.

If you are that concerned, you can purchase and install a Moroso 74050 sealed battery box. It's NHRA approved for installation inside the driver compartment.

It's a stupid idea regardless, car batteries have improved over the years but there are still risks of having exposed car batteries in an enclosed area with no protection. But you are right, I guess it is much like someone who wants to get 100 yards from a tornado, I would just rather not chance inhaling fumes from sulfuric acid or having a battery explode, I've just heard of too many horror stories from my dad and know of people through him who suffered injuries related to fires or exploding car batteries.

I don't know anything about the Moroso box you speak of, but I guess if that is a sealed battery box I'd rather be in a vehicle with that than an exposed battery. I'm just simply saying saying that I think chasers who are throwing car batteries into their vehicle may not realize the dangers of doing so, if they chose to do so than oh well, but I just wanted it to be known that it is dangerous, but hey.. so is storm chasing.

 

[John Erwin]

It's a stupid idea regardless, car batteries have improved over the years but there are still risks of having exposed car batteries in an enclosed area with no protection.

You need to do some research Joey. I think I was quite specific about the precautions required if you need to install a battery in the passenger compartment, but there they are again:

1) You MUST use an AGM or other sealed type battery (ie. Optima). These do not use liquids (Acid or otherwise) and do not vent any gasses during charging.

2) You MUST secure the battery properly. There are battery boxes and strapping systems designed for this purpose.

Obviously keeping the battery under the hood would be preferential, but some of us have no choice and it is quite safe to install one in this manner if you do it properly.

Please be careful throwing around terms like "Stupid" unless you are familiar with the topic concerned. Some of us know what we are doing.

 

[Joey Ketcham]

John, none of my comments were even directed at you or anything you said about any precautions. It was directed at those who just throws a car battery in the back which I know for a fact there are a few who do, that's what I call stupid. If you take the necessary steps to secure it and provide the added protection, then obviously that is being responsible. But I know many people who arent and simply throwing exposed, unprotected batteries in the back thinking it's safe to do.

Some knows what they're doing, but I would suspect that some doesn't even know the dangers of doing it. Throwing an unprotected battery in the back with no protection between you and it is stupid, it is what it is.. sorry if that offends you.

 

[John Erwin]

Throwing an unprotected battery in the back with no protection between you and it is stupid, it is what it is.. sorry if that offends you.

Obviously throwing a standard, unrestrained battery in a backseat is irresponsible, so I am not offended by any discussion on that.

Now that you've further narrowed down what you consider "stupid" I assume we can drop this or take it offline.

Cheers