Back with a few more questions.

[Tamnakz]

I'm hoping to put a small system together in the immediate future. This is mobile in a travelling vehicle, locations all around the US, light varying. I've settled at a 220ah 12v battery bank. I'll have regular but intermittent alternator charging, a/c shore charging when available, and would like to have a solar panel on the roof to negate some of my small daily uses.

Trying to buy from a local company, the best panel I've found is a REC310, and I'm looking at using a Victron 100/30 carge controller. I haven't decided on what type of isolator I'll use from the vehicles charging system yet, I need to do a bit more reading between shunt style and the newer voltage sensing relays.

My biggest concern is equalization. I've got a 100a alternator w' an external regulator, and I know I'm not going to have great sun all the time. Can/will my alternator offer an equalization charge? With a proper isolator, do I need to worry about my alternator overcharging?

Thanks in advance for wisdom!

[Mike90250]

You are much better off with a decent battery bank (couple of 6V batteries in series, not 12V in parallel) and hauling a small inverter generator to charge them with a conventional 12V battery charger when your vehicle is idle. Rooftop PV will be inefficient because the panels are flat and therefor at the wrong angle, so their contribution will be very little.
Sorry it's not the sexy solar solution, but it will work for half the price and no roof leaks, and any Joe can troubleshoot it.

[Tamnakz]

I'm complete aware of the genny option, and I appreciate the suggestion, but it's not one I've explored and discarded. Money is not my primary concern in the decision.

The plan is a pair of Trojan T105re battery, two 6v in series. (which is actually 225ah I believe, but within margin of error for the math involved)

I'm fully aware my 310 watts of panels will likely rarely net me more than a few charging amps, for a few hours a day.

Thanks for your input, but my questions about battery equalization still stand.
Can/Will my alternator equalize a battery bank that size? Assuming they are fully charged before an extended drive.

I'm a novice... but logic and research makes me think an alternator and isolator will only charge a battery to full, it might not supply the necessary current to equalize, but I don't know the science well enough to know if I'm correct. I suspect that if I'm correct, there could still be a relatively simple solution.

[SunEagle]

My RV will easily charge my twin 6v 232Ah coach batteries either through the alternator or through the IOTA 40Amp converter/charger. So I don't see any issue with your handling the Trojans.

[Tamnakz]

My RV will easily charge my twin 6v 232Ah coach batteries either through the alternator or through the IOTA 40Amp converter/charger. So I don't see any issue with your handling the Trojans.

Thanks, Good to know!

[Sunking]

Let's see if we can get you on the right track. You derailed thinking about using any mechanical relay or Diode type battery isolator. You need to buy one made for your alternator. No big deal easy to do. More on that in a second. You want a Electronic Isolator that has the vehicle Voltage Regulator built in to replace your existing VR. As a minimum will have 2-Ports, one for the SLI battery, and one for the House Battery. They come with up to 4 ports. SLI battery voltage is fixed at factory 14.2 volts. House battery has selector for FLA or AGM.

Any battery isolator has only 1 charge mode of Constant Current, Constant Voltage aka CC/CV. In other words a FLOAT CHARGER, and any Float Charger has one voltage. Exactly what you want for the fastest possible charge from an engine/generator. Keep in mind about 30 minutes engine run time is about a weeks worth of a 100 watt solar panel. Depends on the size of the alternator. Think about that for a minute if you drive every couple of days. What value would a panel and controller offer?

Next get out of your 12 volt box. You do not want to use 12 volt batteries. Don't be silly. Use 2 6-volt wired in series of the appropriate AH capacity. If you want 300 AH, then buy 300 AH batteries silly. You cannot do that trapped inside a 12 volt box you are in. Trust me there is a wonderful world outside that box.

OK Sure Power makes the regulators. They come in 4 Groups. Find your vehicle manufacture Group number, and then Select the right Amp Capacity and number of ports you want. It is that easy.

[Tamnakz]

I'm looking at using a pair of Trojan T105re batteries. 225ah via six cells divided into two banks.

Thanks for the information about charge modes.

Back to isolator choice. I'm blindly unfamiliar with the idea of putting one in to replace of your vehicles voltage regulator. Do you mean that it makes the oem one redundant? ...or do you mean remove/replace?

I've got an old Ford. The book specs a 100 amp alternator. I have looked and verified it's externally regulated, but not the output. Presuming I purchase a Sure isolator their site specs for my vehicle, would you install it after or in place of the stock regulator?

[Mike90250]

research makes me think an alternator and isolator will only charge a battery to full, it might not supply the necessary current to equalize

A vehicle alternator will not produce the VOLTAGE needed to Equalize a battery. Maybe Sure Power does something special, to allow EQ voltage to the house battery and not fry the engine computer. Sunking or SurePower should be able to answer that, Otherwise, take a long drive for morning coffee, and after all the batteries are charged, the solar can do the EQ on the house bank.

[Tamnakz]

A vehicle alternator will not produce the VOLTAGE needed to Equalize a battery. Maybe Sure Power does something special, to allow EQ voltage to the house battery and not fry the engine computer. Sunking or SurePower should be able to answer that, Otherwise, take a long drive for morning coffee, and after all the batteries are charged, the solar can do the EQ on the house bank.

Thank you, that goes along with what I know. The Sure Power isolators seem to be just an OEM quality isolator, I don't see where they do anything special. I could be mistaken. I'll wait for Sunkings' response to his info, just in case.

If I wanted to be able to equalize from Shore power... Do you have any personal recommendations in terms of a quality charger that's also capable of equalizing? I'm operating on the assumption that, like my alternator, a standard three stage charger will not equalize for me. I'm budget conscious, but would like to choose a best bang/buck Shore charger that can/will also equalize for me. Given the isolator and my uses, I don't believe I'd need more than a 15-25amp charger to run off AC. Equalizations afaik needs the higher voltage charge, and I know I need a charger capable of being set to do this... do I need a current minimum given my bank size(200-240ah), or will a small charger cabale of equalizing do the same job?

[Tamnakz]

I really like the idea of using a bench power supply to equalize, but I worry about using it as a shore charger when I'm not paying 100% attention... more reading...

[inetdog]

I really like the idea of using a bench power supply to equalize, but I worry about using it as a shore charger when I'm not paying 100% attention... more reading...

If you use a bench power supply as a shore charger, and it ONLY offers voltage regulation, you need to set it to the recommended Float voltage of the battery bank. At that voltage you could forget and leave it connected for days without damage to the batteries.
If it has both a regulated voltage and a current limit it would be perfect for Bulk charging at the regulated current, and finishing with regulated voltage at the Float voltage.

Equalize needs to be watched no matter what the charging source is.

[Tamnakz]

I was bench dreaming about a variable supply as my shore charger, but after more reading realize they're probably more of an upcharge from a charger than initially anticipated.

[Tamnakz]

Sunking? Can you please help me in terms of an isolator with a voltage regulator that ?replaces? my vehicles voltage regulator?

The site you linked groups isolators by charge system type, but does not explain why. Anywhere else I've looked for isolator information says just pick based on the output of your alt, oversize if you so choose.

Based on your info it looks like a Sure 1202 will suit me perfectly. I would just really like to know why it will suit me perfectly. Is there a circuitry difference to account for the different voltage regulator types?

[Sunking]

The site you linked groups isolators by charge system type, but does not explain why.

You have to buy based on how your vehicle manufacture Voltage Regulator works. On your Alternator you will have one large conductor for the output. There will also be a connector with 2 to 3 wires that plug into the alternator. That is the VR, you unplug it, and then plug the connector that comes with the Isolator and use the Isolator VR. You are replacing the vehicle VR with one of your own.

You are right, no other Isolator does that and why you do not want them. Most Isolators just use Steering Diodes which drop 1 volt. So if th evehicle alternator is set to 14.2 volts, house battery only gets 13.2 volts which is not enough unless you have a Gel battery. The Sure Isolator is going to give your SLI and House battery the proper voltages. .

I have used them for years in Trucks with special Electronic equipment. Competition Ear Drum Busters use them in their vehicles with 4000 watt amp Stereos, and Low Riders use them for their hydraulic pumps. You also find them in Wreckers with winches and high power chargers. .

[Tamnakz]

You have to buy based on how your vehicle manufacture Voltage Regulator works. On your Alternator you will have one large conductor for the output. There will also be a connector with 2 to 3 wires that plug into the alternator. That is the VR, you unplug it, and then plug the connector that comes with the Isolator and use the Isolator VR. You are replacing the vehicle VR with one of your own.

You are right, no other Isolator does that and why you do not want them. Most Isolators just use Steering Diodes which drop 1 volt. So if th evehicle alternator is set to 14.2 volts, house battery only gets 13.2 volts which is not enough unless you have a Gel battery. The Sure Isolator is going to give your SLI and House battery the proper voltages. .

I have used them for years in Trucks with special Electronic equipment. Competition Ear Drum Busters use them in their vehicles with 4000 watt amp Stereos, and Low Riders use them for their hydraulic pumps. You also find them in Wreckers with winches and high power chargers. .

Ok, maybe I'm dumb... but following the site you linked, specs me a Sure 1202 isolator. It has three connections, one incoming from the alternator, and two outgoing, one for each battery. Is not this just a simple steering isolator?

http://www.ase-supply.com/Sure_Power...2.htm?CartID=1

This to me looks like a unit that's going to create voltage drop. Am I wrong?

I drive an older Ford with an external voltage regulator. Not sure if this plays in at all...

[Tamnakz]

You are right, no other Isolator does that and why you do not want them. Most Isolators just use Steering Diodes which drop 1 volt. So if th evehicle alternator is set to 14.2 volts, house battery only gets 13.2 volts which is not enough unless you have a Gel battery. The Sure Isolator is going to give your SLI and House battery the proper voltages. .

I have used them for years in Trucks with special Electronic equipment. Competition Ear Drum Busters use them in their vehicles with 4000 watt amp Stereos, and Low Riders use them for their hydraulic pumps. You also find them in Wreckers with winches and high power chargers. .

So... I've spent a few hours reading all literature Sure has available to me, as well as from a bunch of other sources...

Best as I can gather, the isolator Sure sells for my vehicle IS a diode based isolator. They list it as a 'solid state' and don't go into detail past that...
The voltage loss of the isolator seems inevitable, but I can account for it by placing my voltage regulator sensing wire AFTER the diodes instead of before them, the nice thing being on my vehicle this is easy to do while making the computer see the proper voltage, not the pre-diode voltage.

[Tamnakz]

To anyone who might find this later, I've answered my own question.

On my vehicle, Sure specs a very basic isolator. Three studs, one for alt, and one for each battery. This is because the voltage regulation circuit in my vehicle (external voltage regulator) will come AFTER the isolator once it's installed. There will be a voltage drop, but my alternator will see it and account for it.

Thanks a ton for those of you who pitched in, took me one giant friggen circle to figure this one out...