Batteries in Parallel or Isolated?

This quote came from the choosing a winch sticky. didnt want to crowd the thread and get off topic.

ok so when wiring them in parallel you will need a regulator of some sort right? and if so does any one have a reference to some good ones. Also where is the right place and way to install it?


Now if the decision is to go with a dual battery setup and an Isolator you will not be doubling the Ah, just having a battery soley for winching is how i see it.

in this pic it is showing that the primary battery is wired only to the starter...the more common approach i believe would be to the starter and accessories and then the secondary soley to the winch and not "the fuse box".

What is the proper way to conduct this mod should this be the decision?
and should a person go with the diode or solenoid isolator.


I understand that the part of the decision to each setup is personal preference but what are some of the pros/cons to each in your opinion?

I am leaning towards "in parallel" but would like to know what lies ahead in each process before making a final decision.

Also i dont want to end up like this guy with wires running everywhere and no fuses or regulators to be seen!

 

Go with the isolator, batteries in parallel can be a drain on each other and tougher for the alternator to keep charged. Also with the isolator should one battery die you always have the other.

 

hmmm a drain on each other? shouldnt they be losing juice or gaining juice concurrently? one would never draw more or less than the other i wold think?

it being tougher on the alternator i can understand, but i think it would just take longer to bring both batteries to full charge, nothing else.

oh well interesting info, anyone else?

 

ok did a little research on voltage regulators and there is a million different types of 12v voltage regulators! i cant for the life of me find out what one i should use for this set up. someone has to be using a parallel setup...where did you get your regulator and what type?

 

From my understanding, direct parallel connection is fine only if the batties are the same model, make, and age. Optima says the same thing on their site basically as well. No reason for any regulator here.

I would not hook up a regular battery to a different brand (or even the same) deep cycle though

From what you have drawn, it looks like you really should use an isolator, which is pretty much just a diode setup to keep the batteries seperate but both recieving a charge

There are a few different kinds

The simplist isolate the two completely and always, allowing your alternator to charge both. You can have your regular battery doing its regular job, plus and additional for whatever your wanting (winch?)

Others have a 4th post that you can use to either tie into your ignition to have both on with the ignition, the starter relay to have both on for more starting power, or manually with your own switch. Using a manual switch is probably the way I would go. If you need a short burst of more power for winching you would have it, just watch it since you would be draining both batteries. Also, if your main ever died, you could hit the switch and basically jump start your self off the other battery. If I had a setup it would be this if I decided against a parallel config.

If you get an isolator, whatch the amp rating. It has to be at least equal to what your alternator can put out. Personally, I would get a 200amp one if you can find one or at least close to the alternators rating. They arent that cheap though. I havent seen any under 100 for a 200amp one


You can also achieve this via a solenoid. Just make sure its rated for what you want it to do. Some are not built to be left on for long periods of time and are more for starting or short burts (like the old ford ones). Painless has one, any many go that route because its cheaper. If you need to charge the other battery, you just have to connect them together




All said and done, I would parallel wire two new optimas if I had all the options. You could probably buy 2 new batteries and the short wiring for near the same as the other options. Look at diesels, they are just straight parallel, just gotta replace them all at the same time with the same types of batteries.

2nd choice would be the isolator, just spend the money and get the right one. Search around for them. Marine shops, RV's, diesels, and Semi stores sell em.

 

oh..and to directly answer your questions


parallel with the batteries you have would likely ruin both eventually.

isolator (diode) charges both all the time. splits the alternator to both batteries. potential con could be alterntor couldnt charge up your main as normal if splittling with the aux. but really it would just be like charging a huge single battery. ie 2 x 1000amps as 1 2000 amp battery. same as a parallel setup. the models with the toggle feature, basically are acting like an isolator and solenoid combined.

solenoid doesnt normally charge both at the same time. basically acts to connect both together temporarily. i dont get the pro of this really since it wont charge both unless both connected. i suppose its cheaper and typically the amps are higher rated. your main battery would actually discharge somewhat into the drained battery as well, something you dont have with an isolator set up.

and regulator? i see no reason why you would need one at all.

 

yeah thanks for the input you've been a big help. i started looking around and learned a little bit about the concept of batteries and stuff. i think i just took a crash course that is college level! after reading about it i realized that as long as they are the same exact battery and are both at the same exact point inthier life the batteries will not be fighting eachother. they will be acting as one battery. as for a regulator i irealized that was not needed but it was still never actually stated anywhere till you confirmed my feelings.

Again thanks. i think i will go with 2 yellow top 750cc in parallel. seems like the best setup and simplest.