Delica Canada | Mitsubishi Van Club

I am wiring my deli camper up with a house battery system. Xantrex 1800w inverter/charger, shore AC wiring, and some very large batteries: two 6v trojan deep cycles, one over each rear wheel, at 120 pounds each! I'm getting 420 amp hours out of this set up. I have 90 watts of solar panels on the roof to keep them topped up, now I just need to get them charging from the alternator.

I have a motomaster battery isolator and I want to install it, but I'm a bit confused. I have found the alternator and there are a few leads coming off of it. One fatter cable, on a ring terminal with a red rubber cap, is on a threaded post. I assume this is the main lead to the battery, correct?

There are also a couple of smaller wires plugged into the alternator on a harness, I'm not sure what they're for or where they go. I have a couple of questions before I mess something up:

1. should I disconnect all of the smaller wires from the alternator, and put them on the starter side of the isolator? I figure that with the isolator diodes, when the engine isn't running, those wires won't get any power, whereas right now they are connected to the battery + when the engine is off.

2. Is it practical to change the voltage regulator? I have heard that diode isolators cause a voltage drop which can prevent batteries from getting a full charge, and a new regulator with a higher voltage cutout can compensate.

3. Have any of you put a battery isolator system in before? If so, where did you mount it? Any ideas for where to stick it?

Thanks for your help!
David

Having wired in a couple, have to say be cautious with rerouting alternator wires. The fatter ringed cable is always the main, were I've bought a nice new ring connector to crimp in the new 4-6 gauge wire, as DC needs thickness for amps.

Don't know about the voltage regulator, but that is a big inverter. Goggle battery isolator wiring and there is many different wiring configurations.

Kept the isolator close to the engine cause heavy gauge wire is pricey (and shorter is better). What about venting for your house batteries? Charging batteries produces some noxious fumes so would you need battery boxes and exterior venting? Don't know batteries very well, do newer ones not expel gases as they charge?

Someone around has gotta be way more help than me.

Cheers

dpd wrote:2. Is it practical to change the voltage regulator? I have heard that diode isolators cause a voltage drop which can prevent batteries from getting a full charge, and a new regulator with a higher voltage cutout can compensate.

Yes. The voltage regulators that come stock in these tiny alternator's are &^%#&$.

Just a note here, those 6volts require a pretty skokum charging system, and from what I've read about the alternators in the Delicas, I'm not sure that they are big enough to charge up the batteries if you drain them down. You'll want to check the batteries with a hydrometer, and if they aren't charging up properly with your solar panels and alternator, you may need to put a manual battery charger on them to get them fully charger.

Also it is possible that they may burn your alternator up.

Templar wrote:Also it is possible that they may burn your alternator up.

I had my alternator rebuilt twice. Both times the voltage regulator went.

Running everything stock except for a mini-compressor and a 9k lbs warn winch.

The shop that rebuilt the alternator both times said that it's rated at 75 amps but in reality it's a small alternator compared to similar sized vehicles.

I'm in the process of shopping for a larger alternator to fit so that it won't have to keep being rebuilt / voltage regulator blowing.

Not to hijack this thread but I have similar concerns re alternator output. I notice that my small powered sub alone puts added load on the alternator and am wondering about effects of more load with the a/c running in the summer (if summer ever arrives...).

Dunno if I want to get into paying for a higher output alternator at this time though. Can the stock units be rebuilt on a budget to produce moderately increased output?

torchard wrote:Dunno if I want to get into paying for a higher output alternator at this time though. Can the stock units be rebuilt on a budget to produce moderately increased output?

Not according to the shop I took it to. That was my 1st question when I brought it in. They are a major alt/rebuild center.

The voltage reg/bearings/alt parts are commonly available at any shop. A rebuild should not cost more than $150 which would include a voltage regulator, new bearings and a rewind or at least cleaning the brushes.

After two rebuilds, a larger output alt is looking to be a cheaper solution in the long run.

Docsavage did it last year.

http://www.delica.ca/forum/100-amp-alte ... alternator

jfarsang wrote:

Templar wrote:Also it is possible that they may burn your alternator up.

I had my alternator rebuilt twice. Both times the voltage regulator went.

Running everything stock except for a mini-compressor and a 9k lbs warn winch.

The shop that rebuilt the alternator both times said that it's rated at 75 amps but in reality it's a small alternator compared to similar sized vehicles.

I'm in the process of shopping for a larger alternator to fit so that it won't have to keep being rebuilt / voltage regulator blowing.

Already with Granola?

Thanks to all for the feedback.

jfarsang: Do you know of a drop-in replacement alternator with better specs? Even $$$ mitsubishi special order? My alternator is stock, 18 years old, looks like crap. A 100 amp replacement would be nice. Can you remove the regulator on the stock alternator without dissassembling the whole alt?

jfarsang and bcdelica: so what do you think about the additional wires on the alternator? Should I unplug them and put them on the starter-side of the isolator, or leave them as-is? If I leave them on the alt, they won't get any current unless it is spinning, so if they're voltage meters or glow plugs or something, it might be a problem to isolate them from the battery... does one of the wires connect to the regulator, or does the regulator sense current from the main? If there's an extra regulator lead then I have to relocate it for sure or the house battery will never charge.

bcdelica: yep I'm using some fat wires, 2/0 AWG from iso->batteries, 1/0 AWG for all high current appliances (800w stereo, webasto heater, fridge, inverter). They're damn expensive at a stereo or RV store...like $15/foot for 2/0! At the welding supply store, same or better quality stranded cable is $2-3/foot for 2/0 AWG, $1.50 for 2 AWG!!! I'm venting the batteries out of the fridge exhaust through the floor, I read that the batteries vent hydrogen, which is not just noxious, more like kaboom! when the inverter or fridge clicks on so good advice

Templar: There's no difference between 2 series 6volts and a 12 volt. They're both 6 2v cells in series, charging them is the same problem either way. A 60 amp alternator, at 100% output, will take 4 hours to charge the house batteries from 50%... so point well taken about burning out the alternator. I don't think it will run 'harder' when higher Ah batteries are attached, but it might not like running without a break for a whole day! My roof is 60% covered with detachable solar panels in hopes of keeping the house batts reasonably full on their own.

BCDelica wrote:

jfarsang wrote: I had my alternator rebuilt twice. Both times the voltage regulator went.

Already with Granola?

Nope. That was with Paj (Pajero) same alt.

I didn't rebuild the alt. I'm not sure if the volt reg can be removed easily.

I don't know of a drop-in 100A alternator.

I wish there was one, but I haven't seen anyone source it, if it's out there.

The best bet I would think would be to do what James did. Have a separate electric vacuum pump and a generic 100A alternator.

Just takes some work but in the long run it looks like a better option.

Replacement/rebuilds would be cheaper too.

I have a similar setup on my sailboat. 12 volt starter battery and two 6 volts in series as a house bank. I also have solar panels hooked up through their on their own regulator.

I'm not using an isolator, because like you mentioned I've been told the isolated batteries won't receive a full charge. Instead I am using a battery switch and have to remember to turn over to the house bank when the motor isn't running.

I was wondering if you need to hook up to the alternator at all? Couldn't you hook the house bank up to your starter battery in parallel and have the isolator located in between the two banks?

Hopefully Jay from Tardisdeli could jump in here. He does this for a living and we were discussing this very thing on the May long weekend meet.

Good luck
Zissou

If I wire the battery banks in parallel with a one-way isolator, the house battery will equalize with (drain) the starting battery which I want to avoid. (If current can flow from alt->starter->house to charge the house batts, then it follows that it can also flow from starter->house)

Isolating the other way, the house batts will be parallel for engine starts, damaging deep cycle batteries that don't like that kind of cranking amps.

The solution is to isolate both ways (no bank flows to the other at all), the dual-isolator does this, but allows one-way flow from the alternator to both banks. Supposedly the bank with a lower state of charge will cause the isolator to flow current into it, and not into the other, so the regulator senses voltage from the bank that is charging.

It seems like an ideal solution and I think it's widely used in RV setups, just has the problem that the voltage drop from isolator to battery will keep the alternator from charging it all the way. But from what it sounds like with our lackluster Delica alternators, this might be a good thing, sparing the alt and using it for a 90% charge, and then letting the solar top it up long term (solar has its own regulator). As far as not charging the starter battery fully, I think the smartest thing is just to over-spec the starting battery... I need a new starting battery anyway, I'm looking at a big, single AGM spiral cell for this.

The problem with a switch, be it manual or automatic engine-on solenoid, is that as soon as the contacts join the battery systems together you can get massive flow from one to the other as the battery banks equalize. Bad for the batteries, fuses can blow, etc. It's OK though if the charge states are kept fairly high, or close to each other, but one low bank and one high bank and a direct parallel connection can be bad news with large banks.

Disclaimer for everything I'm saying though, this is all research and theory on my part, I don't have much real-world advice to go on, so I would love if Jay and any other pros would join in!

It's OK though if the charge states are kept fairly high, or close to each other, but one low bank and one high bank and a direct parallel connection can be bad news with large banks.

In theory you are quite right, but in practice car batteries, even deep cycle ones, can generally handle that sort of thing quite well, (this is why you don't damage things when you use booster cables for example)
Make sure any wiring that could make a path between the 2 batteries is very large gauge though, just because the batteries can handle it doesn't mean the wiring can!

Add up all of the cable runs everywhere... alternators, solar and AC chargers, inverters, inter-battery cables, fusebox, ... I've been using online voltage drop/wire gauge calculators in choosing wires and I'm definitely convinced that fatter is better. Whenever there's 60+amps, it's 1/0 or bigger, 2/0 for long runs. For 20 amps or less I'll relax about it :) It's amazing how fast you can lose 10-20% of your power with inadequate wire. With charging and spending losses combined, I didn't spend $700 on batteries to lose 20%+ of the capacity (or worse, use the same power but drain the batteries 20% flatter every day and kill their life expectancy that much faster)

Green1, this brings me to my alternative plan, if I can back it up with research or a professional opinion:

Buy the solenoid-type relay isolator which joins the battery banks from key-on. But instead of key-on, wire it to the alternator so that the connection is made when the alternator is charging. That way the battery banks are joined, only when the high voltage of the alternator's charging current is present. I don't think I'd have a problem with battery equalization at all in this case, would I? The 14v of charging current would keep the batteries in check, and the lower charged battery would naturally draw more current? That's the theory anyway... and no voltage drop or overheated diodes in the process. The key-on solenoids are $30 at can tire or my local RV store.

The wiring is simpler too; leave alternator and starting battery alone, just add in 2 wires to the solenoid, 1 for charge sense and the other for main to battery. I won't break anything

It all depends on having a lead on the alternator that is hot when charging, off when not... in other words not continuous with the main power. Maybe one of the pins on the regulator. I'll bust out the multimeter tonight...