dual battery set-up

[Wes Harden]

I'd deff spend the money for a battary isolator. easyier on your altenator. with the soliniod set up, when the soliniod is closed you have 1 big battary to charge. If your main is drained down and your Aux is up the aux bat will be over charged.
I have some 8.5 work vans that were built w/ solinoids, the equip on these trucks will kill the aux batt in 45 mins. When the truck is started the solinoid closes and the altenator starts a heavy whine. On numerous occastions the system voltage was to low to run the computer. (GenIII GMC chassies). I have chewed out our Fleet engineer for allowing the truck to built like this and we will have to rewire 65 trucks to remeady this problem.
Well my 2 bits anyway
Wes

 

[Hannibal]

problem fixed

Thanks for the help guys. It turns out i had a problem with the "excitor field" on my alternator so I fixed tht by having my alternator fixed up with a self exciting field,(1 wire hook-up) then I put in a new colehersee 24143 200 amp continuous duty solinoid with some revamped wiring. Everything works.... for now...

 

[MarcS]

Divicored set up is the simplest (=reliable) and cheapest to do. Painless a little more expensive, but is basically the same, just in a nice kit. Hellroaring and others are a waste of money in my opinion.
(Opinions are like asses, everybody has one)

Diodes have a voltage drop across them. I have had power problems on my boats multi batt system because of this.

The voltage of a fully charged battery and a dead battery is only around
1 volt. Most diodes have about a .7 volt drop. The battery is usually undercharged because of this.

Switches are cheap and easy, but I don't think you supposed to turn them while the engine is running.

 

[Jagged]

Switches are cheap and easy, but I don't think you supposed to turn them while the engine is running.

You should be able to disconnect your battery and the alternator supply the current to run the engine and necessary electronics, so flipping switches really shouldn't affect anything.

 

[keith]

You should be able to disconnect your battery and the alternator supply the current to run the engine and necessary electronics, so flipping switches really shouldn't affect anything.

 

[MarcS]

Look in boating catalogs at the switches. Some have a some type of disconnect (can't remember the name) so they can be switched while running. Otherwise you blow the regulator I think.

 

[diesel4me]

smokes the diodes..

If you run an altenator in an "open curcuit"or "no load",(like pulling off a battery cable with engine running,or turning that switch to "off" with it running)--subjects the diodes in the altenator to voltage surges that can pop them!..thats why they tell you not to do that..

I've "tested" a good many altenators that way and never hurt one,and then I see people online making altenators into welders with no ill effects! ..but I guess it could hurt the diodes like they claim..

 

[Hannibal]

I've asked a few more electrical types and a couple mechanic buddies and the consent seems to be that you CAN switch under load because in this case you typically have the alternator constantly hooked up to the primary battery/wiring with the second battery used for extras and wired seperately. When the switch is "on" the alternator sees a need to charge where-ever it is needed (which ever battery is low) and when the switch is "off" the alternator only sees the primary circuit. Turning the second battery on is no different than turning on your headlights.

 

[MarcS]

Yeah, that makes sense. As long as one battery is always connected, there shouldn't be a problem. A switch has an off position, thats where the problems happen. As for the charge current, each battery will use only what it needs to charge. With Divicored setup, one is always charged to self jump yourself. There will never be 2 dead batteries. (Unless you kill them both jump starting).

I have a 55 amp alt on my boat for years now with 2 deep cycle batteries and never had any problems like I had with diode isolaters. Your alt is HUGE compaired to that.

 

[jekbrown]

good tech to know. I am seriously pondering getting a marine switch and running dual batts that way. I don't really need self-jumping capability or any wizz-bang-foo-foo features... just want both batteries to charge and to be able to switch over to a single battery as needed.

j

 

[ryoken]

same.... considering i have my choice of free switchs from work... we have a few floating around.. its the free, simple solution in my case...

think i'll run mine out in the engine compartment, keep my cabling short.. can't think of any reason that would be too much of an annoyance...

 

[jekbrown]

while we're on the subject, Im pondering getting one of those keyed marine switches I posted a link too.... is there really any reason to run anything but both batteries? When the key is pulled, both batteries are disconnected... and the rest of the time they are both charging and/or being drawn on. Why not run 2 all the time? I have a warn 8274 winch, will it be able to kill both batteries if the engine is running? I haven't had a winch before now, and the trail rides I've been on where one was used, no one ever killed a battery. Thats the only "problem" i could see here that would actually make self-jumping capability worth anything.

j

 

[ryoken]

thats a blue sea switch... good quality stuff.. we run Perkos at work.. right now i have my choice of the standard 4 pos one or the HD one...

i'd actually like the keyed one for that added killswitch security... maybe one will come in...

i'm pretty certain you can bang between 2, all, and 1 without hurting anything while running. but not the off position. but i very well could be wrong, wouldn't be the first time...

my intentions where to mostly just bounce back and forth between 1 and 2 every couple days.. i'm certainly under the hood enough..

only downside to running in all, all the time i would think would be when that joint cca amperage suddenly gets low on a pull where you can't run the motor.. but i don't know sh*t about winches yet...