Battery Isolators... (1 Viewer)

[woody]

I've got a SurePower installed in the rig right now, but the bloody thing soaks a full volt...14amp at the alternator, 13 once it gets split to the batteries....even with clean connections and good quality fine strand wires...

Who's got a good one out there? (this one was a cheapie...)

 

[Rich]

All of the diode based isolaters have pretty much the same voltage drop. The solution is to wire the alternator so that it senses the voltage between the battery and the isolater, otherwise, the batteries do not get the intended charging voltage, as you have discovered.

At the cost of greater complexity, go to one of the relay based systems. For simplicity, use a manual dual battery switch.

 

[Waggoner5]

Manual, less things that can go wrong.

 

[Beowulf]

Woody,

I'm considering the Hell Roaring unit. Yomama has been using one for about 3 years and he is very happy with it.

-B-

 

[Junk]

My late friend Mike Schroth had the hell roaring in his 80 and loved it. Damn I miss that guy.

Woody, I have a SurePower in mine now. They are pretty good. I don't know if they have different lines or not if all are of same quality. I thought the most you should see is about .4 amp drop and that's it. If you're running duals though, it should not be a huge deal should it?

 

[LandCruiserPhil]

Manual, less things that can go wrong.

I agree

Seen several dead dual battery set-ups with those high price isolaters. Plus no voltage loss when you go manual.


Phil

 

[woody]

manuals a good choice...now, tell me how to wire two batteries in so one is exclusive to the winch, the other exclusive to the rest of the rig, and so both get charged....

 

[Junk]

shees Woody, you want them to stop over and do it for you too?

 

[Exiled]

Actually, I'd love to hear the explanation too, that's *exactly* what I want to do with mine, right now I have a dead Mean Green isolator and an unused deep cycle Optima, I want to use a switch and get it over with, tired of fiddling with the isolator and I'm not spending a chunk of cash on one of those solenoid-based systems.

 

[Rich]

Here is how I would (will, when I get more ambition) do it. Blue Sea marine dual battery switch. Has 4 positions, bat 1, bat 2, both, and off. Run the positive cable from each battery to the switch. Ground both batteries together. Connect all electrical loads to the output from the switch. Now you can choose to run everything off of either battery, or both batteries. When you want, you can switch all power off by turning the switch.

When you winch, if you want to use only one battery, the turn the switch to the battery you want to use. You get to choose either battery or both if necessary.

In order to charge both, you need to have the switch set to both. This is the simplist setup, but requires you to manually combine or isolate the batteries as needed for use or charging.

With the addition of a single solenoid, also from Blue Seas, you can set it up so both batteris are paralleld for charging when the engine is running. With this addition, both batteries get charged when the engine is running, regardless of the main switch setting. If you do this, then you need to wire up a disconnect for the solenoid if you want to be able to winch off of a single battery with the engine running.

 

[LandCruiserPhil]

I also use a constant duty relay to connect the batteries together via 1/0 cable. A 3-position switch to control them. 1st position batteries connect when ignition is turned on. 2nd position batteries are not connected under any condition. 3rd position batteries are connected under all conditions.

Phil

 

[ParadiseCruiser]

I would side with Rich and others in using a solenoid switching system. Christo has a wiring diagram on his site that can be used as is, or modified for your particular application.

The schematic is here.

I have used a variation of this set up for some time, with winch, radios, etc. and it works quite well. Here are the advantages as I see it...

1. Less expensive;
2. Installs in a smaller space;
3. No voltage drop;
4. When discharging, batteries are isolated only when engine is not running...

This last point is significant (to me) because when you have a high current demand with the engine running (winch, lights, radio [in transmit], etc.), you are better served with a pair of batteries in parallel, than just a single one - or the other - depending on how you have wired them.

The major "disadvantage" of potential inrush of current from a charged battery to discharged battery is mostly hype, and can be avoided if you wire the system so the batteries do not "see each other" until after the alternator is actually putting out a charging voltage.

Cheers, R -

 

[Mike S]

manuals a good choice...now, tell me how to wire two batteries in so one is exclusive to the winch, the other exclusive to the rest of the rig, and so both get charged....

Woody - that is WHY you use an isolator. The isolator allows current to flow one way only - from the alternator diode input to each battery. One battery is hooked to the regular engine loads, the other to the winch. They both charge from the same source, but do not share power. IMHO, this way better than a manual switch, since it is always available, and you can't forget to switch it back to regular configuration.

The Hell Roaoring product is very good, and they will help you to design the circuit.

Mike S

 

[woody]

Been on Hellroarings site, looks like good stuff....guess it's shoppin time!

 

[skyshark186]

Does look like a worthy product. Just curious, besides winches and stereos what are you guys running that requires this kind of power. My 40 is still in the stone age, though its gaining tech fast.

 

[Junk]

Shark186 - I have all my aux stuff running off the 2nd batt. Leaves the main full charged for starting. I've run things off it like the ARB fridge, all the accessories including microwave, toaster oven, weed trimmer, power tools, backed up to the house and ran the fridge off of it while upgrading the service to 200 amp in the house etc. 1 battery is not an option for me.

 

[badkarma]

speaking of dual battery systems...

I just finished the install on my 69 fj40 using the Painless 250AMP kit. Contrary to what people have said (in this instance) it actually was painless.

I still have the stock alt. putting out 45-55 amps any suggestions/comments on upgrading this? Should I upgrade? How do I test to see what the alt. really is putting out? Yes, I have read the threads with some people still running stock alts. with dual batts. with no problem.

My plan is to add a pair of driving lights, stereo and CB. And of course it's gotta run the laptop for GPS.

 

[mobi-arc]

Before you go out and purchase a battery isolation device, we've designed a battery isolator that is more efficient than anything we've seen on the market. It's currently being ramped-up for production. Why should you consider our product over other products? Let's quickly look at ways to isolate batteries.

One way is a constant duty solenoid. Easy to use. Cheap. Guaranteed to have diminshing performance over time as the contacts arc every time it's switched.

Second way is a solid state device which commonly uses diodes called Schottkey diodes. There are no moving parts, which is good, but the diodes are fairly expensive and suffer from a substantial voltage drop across the diode. This voltage drop (i.e. resistance) manifests as heat which in turn has to be dissipated. This is why most isolators you see come in the form of a giant 3 pound aluminum extruded heat sink. They may annodize it a cool color, but it's not there 'cause it's pretty. It's there so the damn thing doesn't overheat. And as we all know, heat is what ultimately kills products.

Now, what's different about the isolator that we developed at MOBI-ARC?

For starters, its small (approx 4"x1"x1") which makes it easy to install.
There's no aluminum extruded heat sink....because we don't need one! It dissipates so little heat it's ridiculous.
It's scalable, meaning that you can stack isolator modules together and isolate from 100a to 1000a.
Some isolators are specifically designed to work with a particular alternator's regulator. Why? Because they drop so much voltage through the isolator that the regulator needs to be jumpered to the other side of the isolator for it to function properly. Not ours! The voltage drop is so miniscule that jumping the regulator isn't necessary.

We've simply designed the perverbial better mousetrap and we look forward to bringing it to market. Any comments or questions, feel free to e-mail us at info@mobi-arc.com

 

[ian]

mobi-arc:
Nice cheerleading session. Now give us some details on the tech behind your "superior" unit.

 

[mobi-arc]

Nice cheerleading

mobi-arc:
Nice cheerleading session. Now give us some details on the tech behind your "superior" unit.

70 millivolts at 200a. That's dramitically better than any solenoid, any solid-state isolator, any switch on the market. This is with no aluminum extruded fins, no chillers, no moving air; and it can fit in the palm of your hand. The product has a "patent pending" status and we look forward getting it to market. Should it be convenient, we'll be introducing and displaying some pre-production units at the Off-Road Expo in Pomona, CA next week.

Scott
info@mobi-arc.com