First time intro & Electrical Problem

[Siskiyou]

Hello everyone,

I’m new on this list. I live in rural southwest Oregon. I’ve had a 2006 Eagle 4WC for about 2 years. I use it for pleasure and work (as I do biological consulting – mostly wildlife work - that can require a good bit of travel and field work).

I’ve been checking this forum out for a while and get both inspiration (to get out and explore) and practical advice. Thanks very much.

I am gearing up for a 3 week trip down to the south California desert (Death Valley, Mohave Preserve, maybe Anza-Borrego). We love it down there. I’ve made a few modest improvements.

For one thing, I installed a double battery/ isolator system. Found a place under the hood of my 97 Nissan (4WD, 4 cyl, 5 speed) truck for the second battery. Took out the stock windshield-cleaner liquid container (and put a smaller one in a different place) and fit the 2nd battery there. I used a 50 amp-hour (20 hr. rate) AGM battery for the second (RV) battery.

I am having an electrical problem (not, to my knowledge, connected to the dual battery system) and, maybe, someone has some insight.

I lent my camper to friends last summer. They were getting married and needed xtra sleeping spaces for friends & relatives visiting for their wedding. (This was before the dual battery system was installed.) I had the electric line plugged in and, when I retrieved my truck/ camper, the battery was dead. I figured they left a light on for too long though they claimed otherwise.

Recently (and after the dual battery system was installed), I left the electricity to the camper plugged in and the RV battery dropped to low voltage in a matter of days. Nothing was turned on. The only things I knew taking energy were the alarms (one for CO; the other for Propane).

I found on line manuals with specs for these 2 alarms (CCI – model 3400 for CO alarm and CCI – model 7770 for the propane leak detector). According to the specs, together they should draw only about 1 watt. I have a clamp on DC amp meter. There appears to be an approx. 20 watt (1.4 amps) draw coming out of the RV battery and nothing (except the alarms) is on “that I know off”. When I pull the 30 amp main fuse in the 4W camper panel, the draw out of the RV battery drops down to zero.

Having a continuous 20 watt draw is unacceptable. I can pull the main fuse but that’s not a great option for when you want to turn on the light at night, etc.

Does anyone have an explanation for where the juice might be going? Or a way to figure out the problem? Thanks for your help.

Romain

 

[pods8]

I'm wondering if you maybe have a short some where that is burning battery power through resistance in the camper or such. Do you have a fuse block for each individual circuit to check to see if its only in one circuit or in the mainfeed line? Might help narrow down what it could be.

Also when you say plugged in do you mean to a 120V charger? I'd be shocked if that couldn't keep up with that small of a draw so while you need to address that you might what to make sure your charger is actually charging (who knows that may have an issue and its somehow discharging the batteries rather than actually charging them???).

Few more details and we may be able to track things down.

 

[Siskiyou]

Thanks for the reply and the suggestions, Pods8.

A short does make sense. I'll try your suggestions and see if I can narrow it down by seeing what kind of draw I get when I try the 3 other "branch" circuits. (Why didn't I think of that?)

When i say "plugged in", I just mean the connection that joins the 12 volt cable from the RV battery to the cable that leads into the RV's 12 volt system. The battery does seem to be charged by the alternator (voltage gets higher when engine is running and with higher rpms). I'll double check with my dc clamp-on ammeter.

I'll get back after I check out the individual circuits for amperage draw.

Thanks again.

 

[DirtyDog]

Welcome to the board Siskiyou. You done much exploring down in the Trinity Alps area?

 

[pods8]

The battery does seem to be charged by the alternator (voltage gets higher when engine is running and with higher rpms). I'll double check with my dc clamp-on ammeter.


FYI another good check on that front is check the voltage in the battery after its sat for a while (over night would be ideal) and see where its sitting. A lot of deep cycles fully charged will be 12.8-13.1+ volts.

Let us know what you find on the circuits.

 

[HERR42]

pull all the circuit fuses....leave the main fuse in place.

put your meter on the battery.

add fuses back in until you indentify the specific circuit drawing power.

let us know what you find.

divide and conquer!

 

[Siskiyou]

Thanks for all the good advice. Gave it a try with my meters and now I'm really confused! When I re-inserted the main (30a) fuse and took a reading (with my clamp ammeter), I only got a .4 amp reading (not the 1.4a = ~20watt readings I had 2 days ago). Took several readings and that's about what was happening. Pulling the individual fuses on the 3 branch circuits did NOT take the .4a reading down. (Pulled all the fuses and tried fuses individually.) Only when I pulled the main fuse, did the reading go down to zero?

I took a reading on the charge when the motor was running/ alternator was going and both batteries showed about 4 amps going in to each battery. I guess that's beleivable considering the batteries are probably near full? The voltage (for both batteries) with the motor going was about 14 volts and about 12.8 with the motor off.

Oh well! I'll just keep alert, take some more readings later, etc. The .4 amp draw may be "normal" and small enough to not be of concern?

Thanks again.

Siskiyou

 

[Siskiyou]

Hello DD,

Thanks for helping with this forum.

I backpacked in the Trinities many years ago but I'm not that familiar with the area. I"ve backpacked more in the Marble Mountains (but, though I still like to packback occassionally, don't do it as often as I get older & older).

Besides going to the Coast (NO CA & SO OR) a few times, I've been pretty much home bound. Last real trip was June, 2009. Wife and I (and friend) spent about 12 days in Lake County - Hart Mtn. Refuge, Summer and Albert Lakes area, headwaters of Deep Creek (Fremont Nat. Forest). Fyfishing, birding, etc. Love that country but the mosquitoes were fierce this time.

cheers, Siskiyou

Welcome to the board Siskiyou. You done much exploring down in the Trinity Alps area?

 

[pods8]

Thanks for all the good advice. Gave it a try with my meters and now I'm really confused! When I re-inserted the main (30a) fuse and took a reading (with my clamp ammeter), I only got a .4 amp reading (not the 1.4a = ~20watt readings I had 2 days ago). Took several readings and that's about what was happening. Pulling the individual fuses on the 3 branch circuits did NOT take the .4a reading down. (Pulled all the fuses and tried fuses individually.) Only when I pulled the main fuse, did the reading go down to zero?


I'd give the wiring between the panel and your batteries a good look over, you might have a short that is making more/less contact as things may get bounced around.

 

[HERR42]

clamp on amp meters are less accurate at low current readings.

it my not be a problem....do you have a DVM that can be put in series with the battery for testing? ...with a 10 amp scale?

check this out... http://www.powerwerx...-dc-inline.html

this gives very accurate real time power consumption data, voltage levels, peaks, sags, etc.....

 

[pods8]

check this out... http://www.powerwerx...-dc-inline.html


Thats a decent looking meter I'm going to read up on that. I fried my lascar digital volt meter a while back and was going to eventually get a new one but for a few bucks more I may have to consider this. Just need to read the manual to make sure it fits my needs (seems like it does but doesn't hurt to verify).

 

[HERR42]

i suppose what would be good is a definitive listing of the true power consumption of the various items, furnace, lights, etc. ....and done with one of these quality measuring devices.

i use mine for my amateur radio stuff....i run on batteries a lot.

i was thinking that i would wire a pigtail (my meter has powerpole connectors) to the camper battery and run a test. i could get watt hour requirements for each device....each test could be...a minimum of 5 minutes and the meter will average that out while also recording peak consumption.


that company puts out another version of the product...it has a different set of parameters reported....and a higher current rating. not true, just different params.

 

[Siskiyou]

Good ideas, Herra 42 & Pods8, I'll send a message when/ if developments occur. The Watts Up & Doc Wattson both look like useful products for auto and rv electric stuff. Best & thanks, Sisk

clamp on amp meters are less accurate at low current readings.

it my not be a problem....do you have a DVM that can be put in series with the battery for testing? ...with a 10 amp scale?

check this out... http://www.powerwerx...-dc-inline.html

this gives very accurate real time power consumption data, voltage levels, peaks, sags, etc.....

 

[Jack]

I installed a 50A, 50mV shunt in line with the battery when I installed my solar panel. Shunts can be had for $12 on eBay. You can then easily measure the voltage across it to get current any time you want with a $25 radio Shack DVM. (Amps = Volts / shunt resistance). I also installed the Whats Up meter at the distribution panel to measure camper load and other parameters.

 

[HERR42]

what has the max charge current been?

Specifically, the charge current from truck to camper ... after the camper battery has been run down. i.e. with the camper battery @ low charge, and during the first few minutes after the truck alternator is given the load by the battery isolator

thats the only thing left i have not measured....i would have to reverse the watt's up....your shunt allows you to do this.

running the battery down to 11.5v prior to testing should be a good test. FWC puts a 30a series thermal breaker in line and i wonder how much margin exists. it seems there is enough margin to support a second battery.... but i wonder.