Nps second alternator

[Cuddy]

Refresh...

Ok, so I will only be running one dc charger in the caravan which is 25 amp at 12 v. It will run through the 6 b&s cable- around 8m in length. The feed will come directly from the truck start batteries -24v. So the max current on this circuit will be 25amps ( at 12v) - as mentioned relatively simple/ common setup

There will also be another 12 v battery on the truck using the same setup-same dc charger output.

I am more concerned about the additional load.

With this setup I am assuming the total added draw on the alternator will be approximately 30amps at 24v.

Do other truck owners have similar added loads to there alternators without any problems ?

Thanks again for of the input

 

[Cuddy]

I am about to install a second alternator (120 Amp) in order to charge my 6x 12v deep cycle batteries on the FG84 whilst on the move.

The only challenge I understand is finding space for such a large alternator, they normally fit 100 Amp alternators to trucks or so I am told.

I am having the add-on alternator installed by a truck refrigeration specialist who makes up the engine mount etc it is something they do on a daily basis.

I could obtain some details and a photo once installed but can suggest that you speak to a supplier of truck refrigeration units as these trucks are often fitted with a second alternator.

The Isuzu has plenty of room on the passengers side of the engine, this is where the compressor to run freezer bodies is usually mounted on the nprs. As you mentioned these guys make up brackets daily so I was going to look for one at a wreckers to modify to suit an alternator, but I am now thinking my standard alt may do the job.
Good luck with the mod.

 

[SkiFreak]

With this setup I am assuming the total added draw on the alternator will be approximately 30amps at 24v.

What's the max current output of your standard 24v NPS alternator?
Is that additional 30 amps continuous or intermittent?

 

[Cuddy]

80amp 24v. The load would vary as the batteries reach different states of charge, I am assuming. The only constant will be the fridges- (estimate around 7-9 amps 24 v draw)
Cheers

 

[javajoe79]

Have you considered a high amp alternator that doesn't have a vacuum pump, then add an electric vacuum pump? That is what I am doing on my Cummins swapped NPR. I considered mounting an NPR alternator but was surprised to find they are quite lacking in amps and there is no affordable high amp alternative with a vacuum pump. I bought an electric vaccum pump for a couple hundred dollars that has a vacuum switch to turn it on when vacuum gets low. It does 24hg

 

[gait]

just a thought ..... the Redarc can supply 25A at 12v to van battery and fridge. Fridge takes 14A (I think from first post). Which leaves about 10A for battery charging.

What size battery, what is it used for, will there be enough driving time to recharge, any other source (like solar)?

 

[trackadda]

did you say if you have any solar panel panel on the van or truck, it wouldn't take a lot to push in say 15 amp/hour via solar while traveling and still putt it in when stopped, maybe one more battery and some solar, gas can get pricey and hard to get in some places. just my thoughts, feel free to ignore if you wish

 

[Cuddy]

Hi Gait, Van battery is 100ah. Runs lights, 12v tvwater pump, 12v stereo. Has 80 watt solar. Not huge power requirements.

The way I see it I need to be able to run the fridge when I am driving. As far as I know the gas should be turned off when towing van, so fridge must be run on 12 v. To do this I need to convert the 24 v to 12 v. Seems like the best way for the money is the dc dc charger, this way I can get I can also get a bit of charge into the battery, even on shorter drives. I am also thinking the draw from the van fridge will be less if I haven't got it cranked right up, leaving a few more amps for charging purposes.

Trackadda, I had thought about the extra solar/batteries but I think the cost will be a bit more than my budget is allowing, plus van will have to be parked in sun. I will Also have a 160 w mobile panel set up that I will connect when stopped up. Think the fridge will be reasonably efficient on gas....hopefully, will know in the next week or so when van arrives

Thanks

 

[gait]

sounds like a reasonable balance to me. I just thought it was worth checking.

 

[dan85]

hey Cuddy, I havent read through everything so im probably going over whats been said. 14amp would be your max draw from the fridge not normal running draw. In my old patrol i had a 105AH 12v battery that i used to run a fridge/freezer, led lighting, radio, charging of phones tablets and camera batteries. I used a CTEK D250S DC-DC charger and never had an issue the battery was always well charged from the stock patrol alternator which is i think 90amp/12v. I had a 120w folding solar panel that if we parked up for a while i would put out and it was able to supply more than enough power to keep the battery topped up. If the Redarc DC-DC charger is the same as the CTEK you can attach input from solar panels and the alternator and the ctek does the rest. which means if your drawing alot of amps for whatever reason from the alternator the charger will auto swap to the solar panels if they are producing more power.

 

[Cuddy]

Hi dan , yeah red arc will do the same. I have just ordered all of the gear to start getting everything set up so we will see how it goes.
Cheers

 

[JohnRogers]

My 2008 and 2010 both run 80amp alternators but no vacuum pump on them so upgrading is easier