Battery Isolators,Separators, and Switches?

[shenrie]

perfect! again, thank you for taking the time to write this up and make all the illistrations for everyone. super great info for the noobs like me!!

 

[Spoolin]

I just want to say thank you for this write up. I'm about to start tackling my house electrical and this has answered all my questions about what I had been wanting to do. A friend actually gave me a silicone based Isolater but think I'm gonna go with the Perfect switch. Not sure yet but this has put me on the right track! Thanks for the wonderful write up!!!

 

[E350-SMB]

Scalf77: As a completely different alternative, with the 7.3L we have two positions for alternators. And our alternators are not controlled by the PCM. So can't we have two completely separate charging systems? One which independently charges the starting batteries. And the second which independently charges the house battery. And, thus, forget this entire topic?

What are the benefits/risks/detriments to my suggested solution?

For later engines: If an engine has positions for (i.e., room to install) two alternators, and the first alternator (the starting battery alternator) is PCM controlled, why couldn't a second alternator which is regulator controlled (e.g., internal to the alternator) be installed in the second alternator position? They would be independent of each other so why would it make a difference if the PCM did not control the second alternator?

Finally, and most importantly, thank you for the great article.

 

[jumpshowhigh]

Yes, you could have two alternators with each alternator charging its own battery or bank....that would be an ideal situation but depending on the engine, a second alternator isn't always feasible.

Scalf77: As a completely different alternative, with the 7.3L we have two positions for alternators. And our alternators are not controlled by the PCM. So can't we have two completely separate charging systems? One which independently charges the starting batteries. And the second which independently charges the house battery. And, thus, forget this entire topic?

What are the benefits/risks/detriments to my suggested solution?

For later engines: If an engine has positions for (i.e., room to install) two alternators, and the first alternator (the starting battery alternator) is PCM controlled, why couldn't a second alternator which is regulator controlled (e.g., internal to the alternator) be installed in the second alternator position? They would be independent of each other so why would it make a difference if the PCM did not control the second alternator?

Finally, and most importantly, thank you for the great article.

 

[jage]

In the dual, separate alternator, what controls keep the alternator from over-charging each set of batteries?

I think I'd rather have normal dual alternator and a separator- a lot more flexible and you get the power of duals rather than running two separately.

 

[daveb-SMB]

I agree but I would like a better regulator.
Myself I have yet to have any issues with my heavy duty alternator. I can see issues with standard belts trying to turn big alternators but serpentine belts are fairly large. We have fleet vehicles with high amp alternator and haven't had issues but there might be a limit to size.
Guess time will tell :b1:

 

[E350-SMB]

In the dual, separate alternator, what controls keep the alternator from over-charging each set of batteries?

Correct me if I am wrong, but the same thing that prevents a single alternator from over-charging a battery -- a regulator. The alternators for the 7.3 have the regulator inside the alternator, so I believe they are stand alone units. The Ample Power alternators which Chance posted not only have their own regulator, but have temperature compensation so as to vary the charge depending on the battery's(ies') temperature (so as not to boil it over), and are "smart" in that they go from bulk charge to float charge, and they also have a remote LED monitor to display what the alternator is doing/battery charge condition.

See:

http://www.amplepower.com/products/alte ... index.html

 

[Scalf77]

I agree if you wanted to go the way of dual alternators, that using the amplepower solution would be the way to go. It would certainly turn it into more of a true charging system. While I agree with the benefits of temperature compensation, I am not sure that it would stop boil over. Not saying it still doesn't look like a good system. It probably deserves it own thread for real discussion.

Dual alternators give you two completely isolated systems, this could be a plus or a minus, but on average I would score it a plus. It would be easier to debug at least theoretically.

Dual alternators certainly give you more power, it would really depend on your needs, I think most of us can get enough power out of one of the higher power alternators available. If you only need a max of 180 amps having 300 amps available does not really matter. I do not think just using a standard internally regulated alternator for the second alternator makes it worthwhile if you could get the power out of one.

I suspect that having one alternator being controlled by the PCM and the other by its own regulator would be just fine as long as they were truly isolated.

So while I see benefits in doing this, it appears to come at a higher cost then just using a separator. That money may be better spent on a monitoring system and/or solar.

If you never plan on plugging in or having solar, then using the amplepower solution becomes even more attractive.

-greg

 

[BrianW.]

This thread is an amazing resource. Thanks to all who contributed!

Question: I have a 1998 Ford SMB 5.4 gasser with the older Sure Power isolator setup. Although I haven't had any problems with it, just to be proactive I'm thinking of replacing it with a separator. I don't have solar yet, but am hoping to add a panel or two in the future.

With that in mind, would I be better off going with the Surepower 1315 or 1314? Or are people liking the Blue Sea separators more than the Sure Powers? The Blue Sea has a higher price tag at ~$170 vs ~$100 for the Sure Power 1315-200. I would like the option of being able to use the house batteries to start the van in an emergency, but I've never had any problem with my van battery going dead.

Also, if anyone has the instructions from SMB-West about replacing the isolator with a separator, I'd love to get a copy. Calling SMB-W often can be a time-consuming came of back and forth.

Thanks!

 

[rockbender]

If going the SP route, get the 1314 to go with the solar. The reason being is that the 1314 only senses charge / connects when voltage is high on the starting battery side. Otherwise, with a 1315 that closes when it sees voltage over 13-ish from either side (I don't remember the exact number) you can have a scenario with very discharged house batteries and when the sun comes up the solar panels raise the voltage to a point on the house batteries that they connect to the van battery. Now you have your van battery and house battery trying to equalize each other and effectively discharging your starting battery.

Also, the isolator solenoid itself pulls about 1a. When you only are getting 2-8 amps (depending on sun and your solar array) the last thing you want to do is give up 1a just to power a switch.

I've got a 1315 but manually disconnect it while camping. This makes it not so much of an automated switch now! I might put a relay in that makes it connect when the engine is on to automate it a little more... or just buy a 1314/Bluesea down the road.

 

[daveb-SMB]

Myself, I have enough solar to charge both battery systems. I had nothing but trouble with Surepower and after several units replaced I went with the Blue Sea 7622. I have had no issues since. I also purchased the remote kit but if you have access to the separator it has full controls on it. By having the separator connect while the van sits outside not in use, the solar keeps both battery systems fully charged. Usually by morning my all systems are fully up w/I two hours. With the blue Sea, if either battery banks fall below 12.8, the separator opens. In the open position the solar only charges the house bank. Once the house bank is up, the separator closes and charges both systems as normal. The solar controller ramps down as the banks reach full charge. Batteries the routinely cycle up and down generally loose their life faster over time so solar helps unless there is a problem with one of the batteries. It's why you need to check the charge from time to time no matter how and what you charge with. One thing I did do was to install AGM starting batteries. I've never had issues with the Lifeline 4-d's I have on board but the wet cell starting batteries were nothing but trouble. My system is set to charge AGM's not standard wet cell types and I think that was possibly an issue but can't swear to that. After switching to AGM starting batteries I haven't had any electrical issues with my charging schedule(s) since 2009.

BTW, I never found the reason why the Surepower units failed. Many members use them with no problems and I'm not out to trash the product, only that my setup was problematic using them and the Blue Sea has been trouble free.

 

[LenS]

I use a Sure Power p/n 15778 120 amp isolator Installed it in April 2004 (9+ years ago). The OEM battery in the 2000 Express van was replaced for the FIRST TIME this year at the age of 13 years. Normal battery life for our vehicles has been in the 7-8 year range. I don't think the isolater added life to the battery...it just didn't take it away. When I added the penthouse I gave away my old 7 year old house battery and replaced it w 2 batteries that are now 5 years old w no noticeable capacity loss .... yet.

At idle the OEM alternator is supplying 15.2v to the isolator (center post) and the diodes have about a 0.8v drop (end posts). I am charging the house and vehicle batteries at about 14.4 volts.

i'm very happy w the Sure Power Isolator. Would be open though to try something different if the price came in about the same or better yet lower.

Price check: PPL Industries has a 55-9419 120A w exciter for $68 plus connector kit $23 plus shipping $10 ............ So a replacement would cost $101 (although as a replacement - not new installation = I wouldn't need a connector kit)

 

[Scalf77]

If I was to choose the Surepower separator I would go for the 1314-200 or if I was willing to spend more I might look at the Surepower 3104. It has more features, higher capacity and latching solenoid, and very configurable. You can make it bidirectional or unidirectional, plus more. The $300.00 price tag seems to be what makes questionable. I don't think the automatic bidirectional features of the 1315 make it a good choice with solar, but that is my opinion. I do really like the Blue Sea Units but they are a bidirectional. I do use a BlueSea 7701 instead of the Bluesea 7620 it is just the magnetic latch solenoid used in the 7620. It is a little more difficult to hook up, as it does not do the voltage sensing. The failure mode I had with the Surepower was pretty much in line with a high current solenoid, they did have a recall after having at least one unit catch fire, I believe they thought it was a manufacturing problem.

I would check to see if you are getting similar readings to Len on your current isolator. Not all alternator systems compensate for the diode drop as well as his. If your isolator is getting older, and you looking at a preventative replacement. I would certainly go with a separator of some version. I believe they are easier to trouble shoot and more configurable than an isolator.

To change over to a separator from a isolator, I would go back to a stock alternator to battery connection. The separator can be installed inside the coach, chances are that you are going to want to beef up the cable going to the house battery anyway, especially if you plan on using as an emergency jump source. You will want a fuse accordingly. The connections on the Surepower 1314 or 1315 are 3/8 while the Bluesea products are 5/16 (so even if you can use the existing cable you may need to change the lugs)

If you choose the *1314 or 1315 I would add a switch to the ground input. This will effectively disable. You can also add a switch to force it to connect, using the start assist tab. If I had the 1315 I would wire the start assist with a momentary switch, the 1314 I would be inclined to go with as standard SPST. In either case you want to make sure that these switches are located in a position that they can not be inadvertently switched.

-greg

 

[Ford_6L_E350]

I don't think the automatic bidirectional features of the 1315 make it a good choice with solar, but that is my opinion. -greg

Why do you say that? I really like the bi-directional feature. My solar panel keeps my starting batteries fully charged because of that feature, and I can't think of any drawbacks.

Mike

 

[Scalf77]

Mike,

I generally agree with the two posted by rockbender a couple of post back.

rockbender wrote:
Otherwise, with a 1315 that closes when it sees voltage over 13-ish from either side (I don't remember the exact number) you can have a scenario with very discharged house batteries and when the sun comes up the solar panels raise the voltage to a point on the house batteries that they connect to the van battery. Now you have your van battery and house battery trying to equalize each other and effectively discharging your starting battery.

Also, the isolator solenoid itself pulls about 1a. When you only are getting 2-8 amps (depending on sun and your solar array) the last thing you want to do is give up 1a just to power a switch.

.


The other thing is that it can tend to mask problems with the starter battery, until these problems become bigger and thus maybe causing issue's with the expensive house batteries they are connected to.

As far as keeping the starter topped off? does it really need that all the time, if I am going to leave the van parked for a longer period of time I can turn the solenoid on manually to top it off before a trip.

So for me the positives don't outweigh the negatives. That said, I would not go out and replace the 1315 to a 1314 for just these reasons. But, if looking to purchase new I would choose the 1314 over the 1315.

-greg

 

[Ford_6L_E350]

The batteries won't try equalize each other.

When solar charging has the house batteries up to 13.2V the separator will connect the house and starting batteries. The starting batteries will be at a float level around 12.6V and will start to accept charging. If the house batteries were so low that the starting batteries will discharge into the house batteries either the separator would never connect, or it would disconnect when the battery voltage dropped below 12.6V.

My van seldom gets used between trips and the self discharge of the starting batteries could be an issue if the solar panels didn't keep them topped off. Of course my van is a diesel and needs more battery power to start it, but I've had no battery issues and the starting batteries last 6+ years. And the fully charged starting batteries make life easier for the FICM.

I will agree the start assist feature can mask issues with the starting batteries and I have never connected that part of the separator.

Mike

 

[daveb-SMB]

I have to kinda agree with Mike on this. I really don't care if the battery banks "bond" together because I have AGM's all around. Sure they are different sizes but it hasn't become a problem for me since I made the change. One issue that I've already posted is that in the RV world (& boating world) the best solution is having completely separate solar charging capabilities for each bank and only a tie switch for emergencies to assist starting. I still believe banking different battery types is a poorer setup but I don't need the perfect solution; only something that works for me. Since my Blue Sea separator is configured to separate during startup I have no issues telling when the starting system is failing. Jeesh, if you think about it why not have separator between the starting batteries on a diesel to protect them from each other? Sometimes keeping things simple makes sense, but I have to admit I do like as much control as possible. The separator (when working correctly) keeps both banks at 12.8 or higher and today I'm OK with how it functions. YMMV.

 

[DosMars]

Thanks for a very informative thread, I've come back to it a few times to become more familiar with my vans electrical system. I've recently developed a phantom drain that leaves my starter battery dead unless I connect it to the trickle charger at night.

From what I've read, I must have a separator since my house batteries are not affected by the drain. I'm going to take it into the shop to have the issue tracked down and fixed, but I'm very interested in setting things up to use the house batteries as a backup to start the vehicle if something like this ever crops up while I'm out in the boonies.

When I picked up the van last summer, the previous owner gave me what I now recognize is a Blue Sea 7620 battery separator. The folks at Sportsmobile had sent it down to him as a fix to some electrical problem that he was having that apparently worked itself out (don't recall the specifics of the conversation as anything electrical tends to go right over my head...) Deductive reasoning tells me that I already have a Blue Sea installed and that it's working?

Question:
-Where would it be installed? I know I could follow the wires but it's pretty tight under the hood (2002 7.3L Powerstroke).

-Will the Blue Sea allow you to use the house battery to start the vehicle? If so, how do I go about this?

The van originally came with a full solar system. The original owner (not the owner i bought the van from) apparently kept the panels when he sold the van. It still has the solar controller so I'm hopping in the future I'll be able to simply mount and plug in new panels and be ready to roll.
-Will the Solar Boost 2000E my van has along with the Blue Sea I'm assuming is in there somewhere top off my vans starter battery as well as the house batteries; or would I need to rig up something additionally to make this work?

Thanks for any input & sorry if I'm repeating anything that was previously gone over in the thread. I re-read the original post but haven't gone through any recent postings since first finding this thread.

-Mark...

 

[Scalf77]

Mark,

Where would it be installed? I know I could follow the wires but it's pretty tight under the hood (2002 7.3L Powerstroke).
Being a 2002, it would not have had a Blue Sea Separator installed from the SMB, for that fact it would not have had a Surepower 1315 either as they started in 2004. I would suspect they used a surepower isolator, but it may have been changed along the way. Isolators are usually installed in the engine bay, while a separator would not have to be. Mine was installed inside the van, in close proximity to the inverter/charger. For my van that is under the side gaucho.

-Will the Blue Sea allow you to use the house battery to start the vehicle? If so, how do I go about this? .

Yes, it is possible to wire in a switch to give you manual control. I don't think SMB installed them with the switch unless requested.

-Will the Solar Boost 2000E my van has along with the Blue Sea I'm assuming is in there somewhere top off my vans starter battery as well as the house batteries; or would I need to rig up something additionally to make this work?

The BlueSea is bidirectional so it will do that by default.

There is a good picture of a isolator posted by Lens in this thread a little ways back. It goes between the alternator and both house and van batteries, while a separator like the BlueSea goes between van batteries and house batteries, with the alternator going to the van battery.

Greg

 

[DosMars]

Greg, thank you so much for the quick reply :b5: .
From what I remember of the conversation, it sounds like the Blue Sea was to replace the separator. He was pointing out under the bench to where it sounds like the separator would be found.

It looks like I'll be asking the shop to instal the Blue Sea with a switch while they're under the hood chasing down the short... I'll consider the extra labor to be coming from the money I'm saving not buying a shiny new Blue. :a1: