bestbowl Posted August 1, 2011 Share Posted August 1, 2011 The auxiliary battery in my '94 Warrior for some ridiculous reason has a 10 (maybe even 12) gauge wire for the positive post and about a 2 gauge for the negative post...? I would think if anything they'd be reversed if not the same... Anyway, I would love to put at least 4 gauge on the positive post as I have recently installed a 130 amp alternator and I pull 400-800 watts constantly out of the auxiliary battery while driving to charge electric bike batteries. Would this be an easy task? It doesn't seem to easy to get to the wiring harness for the auxiliary battery charging system. Is there some way I could do it thru the breaker box or would I have to run it directly to the under the hood battery? Thanks Quote Link to comment Share on other sites More sharing options...
waiter Posted August 1, 2011 Share Posted August 1, 2011 To gain the full benefit, you need to run a #4 all the way from the battery to the Alt (or truck battery). The path will take you through several circuit breakers (or fuses) that will need to be increased in size to handle the higher current flow. And the path also includes the Isolator, If its a standard mechanical solenoid type, it should handle the higher current load. If the intent is to charge you other batteries through an inverter. You might consider wiring that inverter to the truck battery through its own isolator. This will effectively do the same thing but should be easier wiring. John Mc 88 Dolphin 4 Auto Quote Link to comment Share on other sites More sharing options...
Maineah Posted August 2, 2011 Share Posted August 2, 2011 Usually it's a #8 good for around 30 amps. I agree with waiter wire the inverter to the truck battery just bring a 120 volt cord inside the cab from the inverter under the hood buy another isolator relay and wire it to the key power. The breakers are 30/35 amp you'll need to fuse your coach wire at 135 amps or less that's a wopper of a fuse if you are going to use a #4 and take advantage of the current if you don't one of two things will happen the battery will blow up or your MH will burn to the ground if there is a short. I think most of the older isolators had 75 amp ratings and yes it has to go to the front at around $5 a foot + connectors I would not use THHN because it is not flexible enough for vibrations you'll get with a MH use proper #4 battery/automotive cable if you are going to do it. Quote Link to comment Share on other sites More sharing options...
Maineah Posted August 2, 2011 Share Posted August 2, 2011 Usually it's a #8 good for around 30 amps. I agree with waiter wire the inverter to the truck battery just bring a 120 volt cord inside the cab from the inverter under the hood buy another isolator relay and wire it to the key power. The breakers are 30/35 amp you'll need to fuse your coach wire at 135 amps or less that's a wopper of a fuse if you are going to use a #4 and take advantage of the current if you don't one of two things will happen the battery will blow up or your MH will burn to the ground if there is a short. I think most of the older isolators had 75 amp ratings and yes it has to go to the front at around $5 a foot + connectors I would not use THHN because it is not flexible enough for vibrations you'll get with a MH use proper #4 battery/automotive cable if you are going to do it. Quote Link to comment Share on other sites More sharing options...
bestbowl Posted August 2, 2011 Author Share Posted August 2, 2011 " I think most of the older isolators had 75 amp". I installed a 130 amp alternator already. Does this mean I need to install a 130 amp isolator? Also where exactly is the isolator located and do you have a link/ know of a website where I could buy a 130 amp isolator if one is needed? Thanks again Quote Link to comment Share on other sites More sharing options...
bestbowl Posted August 2, 2011 Author Share Posted August 2, 2011 " I think most of the older isolators had 75 amp". I installed a 130 amp alternator already. Does this mean I need to instal a 130 amp isolator? Also where exactly is the isolator located and do you have a link/ know of a website where I could buy a 130 amp isolator if one is needed? Thanks again Do I have to install something like this? http://www.dealsourcedirect.com/41450.html Quote Link to comment Share on other sites More sharing options...
waiter Posted August 2, 2011 Share Posted August 2, 2011 Your original solenoid Isolator should be good for 150 amps continuous, 300 surge. JOhn Mc 88 Dolphin 4 Auto Quote Link to comment Share on other sites More sharing options...
Maineah Posted August 2, 2011 Share Posted August 2, 2011 Very common isolator relay http://www.colehersee.com/home/item/cat/168/24059-08/ The rating is more about heating at 65 amps, will it stand 100 or more? probably but it will get hot . You will be OK with the relay because you are charging two batteries also it depends a lot on the size of your wire you can't push a lot of current down a small wire and you likely will never see your battery requiring 130 amp charge all at once. Your amp rating is current draw the alternator does not put out 130 amps all the time but it is capable of producing 130 amps if there is a need. Quote Link to comment Share on other sites More sharing options...
bestbowl Posted August 2, 2011 Author Share Posted August 2, 2011 Thanks for the info. It makes more since now. I will keep the OEM isolator till I get back from the road in Sept. and then put in a larger amp rated one. I just hope my MH doesn't "burn to the ground"... ;-) Quote Link to comment Share on other sites More sharing options...
craige Posted August 4, 2011 Share Posted August 4, 2011 What was the cost of the new alternator? Does the larger alternator use more of the engines HP? Quote Link to comment Share on other sites More sharing options...
waiter Posted August 4, 2011 Share Posted August 4, 2011 746 watts per Horse Power. 130 amps @ 14 volts = 1820 watts = 2.4 HP 50 amps @ 14 volts = 700 watts = 0.9 HP John Mc 88 Dolphin 4 Auto Quote Link to comment Share on other sites More sharing options...
bestbowl Posted August 10, 2011 Author Share Posted August 10, 2011 What was the cost of the new alternator? Does the larger alternator use more of the engines HP? http://cgi.ebay.com/ebaymotors/120667409633?ru=http%3A%2F%2Fmotors.shop.ebay.com%3A80%2Fi.html%3F_from%3DR40%26_trksid%3Dm570.l2736%26_nkw%3D120667409633%26_fvi%3D1&_rdc=1 90 bucks Quote Link to comment Share on other sites More sharing options...
Bob C Posted September 8, 2011 Share Posted September 8, 2011 As I recall, the larger alternator will use more gas when it is putting out full power. However, as the battery gets charged, the power use drops off. Is this correct or am I reliving the 70's again? Quote Link to comment Share on other sites More sharing options...
waiter Posted September 8, 2011 Share Posted September 8, 2011 Bob, Yes. you got it. If your running electrical loads that require 50 amps (lights, AC blower, Electric frig, etc) then your engine is devoting 1 hp of its energy to generating electricity. Not a lot compared to the hp required to move the Toyhouse down the road at 60mph. If your interested in how much hp your touyhouse is generating while traveling down the road at 60 mph. here are some rough calculations. ******** WARNING - MATH AHEAD ********************** .45 lbs per hp per hour (Brake Specific Fuel Consumption for Gasoline - This number varies depending on engine efficiency, timing, mixture, etc- Between about 0.35 and 0.55)) 60 mph 13.5 mpg Gasoline = 6.1 lbs per gallon (varies slightly with blend and temperature) 60mph / 13.5mpg = 4.45 gallons per hour 4.45 * 6.1 = 27.2 lbs gasoline per hour. 27.2 / 0.45 = 60.5 hp (For extra credit - My 1997 Toyota Camry gets about 33mpg while traveling down the road at 70mph - How many hp is it generating?) John Mc 88 Dolphin 4 Auto Quote Link to comment Share on other sites More sharing options...
Sunrading Arkansas Posted February 21, 2013 Share Posted February 21, 2013 @Waiter: 28.754 Hp (retaining the constant that engine efficiency, timing, mixture, etc. of a Toyhouse = that of a Toy Camry...ha). Woo Hoo! I CAN MATH! Love this forum, it's so in-forum-ative. Quote Link to comment Share on other sites More sharing options...
waiter Posted February 21, 2013 Share Posted February 21, 2013 Pat, You win the prize. I would guess between 20 and 30 hp. The .45 is probably high for an efficient fuel injected engine.JOhn Mc 88 Dolphin 4 Auto Quote Link to comment Share on other sites More sharing options...
zero Posted February 22, 2013 Share Posted February 22, 2013 http://cgi.ebay.com/ebaymotors/120667409633?ru=http%3A%2F%2Fmotors.shop.ebay.com%3A80%2Fi.html%3F_from%3DR40%26_trksid%3Dm570.l2736%26_nkw%3D120667409633%26_fvi%3D1&_rdc=1 90 bucks The link isn't working . . at least not for me. I put a 120 amp alternator on my 2.2 Toyota. I wanted the 50 amps at engine idle, not the 120 amps at full charge. Quote Link to comment Share on other sites More sharing options...
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