Agile battery separator

autostaretx

Erratic Member
on the 10 amp scale, "0.26" is 260 milliamps. (think: a quarter amp is 0.25 amps ... which is 250 milliamps)

If it was trying to show you 9 amps plus 260ma, you'd see: 9.260 (but the final zero is invisible)

So the two meters agree ... and that's far too much current. (any other NCV3 owners care to do a comparison measurement?)

I'm not 100% sure, but i think you're the first (or perhaps only 2nd) person to report the "sleeping" current :thumbup:

more math: let's call it 1/4 amp ... so in 24 hours, you'll have burned 24*1/4= 6 amp hours.
That shouldn't flatten a battery.
In 10 days you'd have gone through 60 Ah, which would be 60% down.

--dick ("far too much": at least twice what i'd expect, and 6 times more than my T1N)
 
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Inspector

2012 Roadtrek Agile
Thanks for jarring me back to seeing clearly, the 1/4A is indeed 250ma, why I got derailed must have been a brain stumble.
So it seems like something is pulling more than it should? I still have the separator ground wire off but I can't see where that would have any influence. The battery may be defective as well as a drain?

Thanks,
Steve
 

Inspector

2012 Roadtrek Agile
I looked back on the M-B. Work order that the tech wrote the parasitic drain values he found,which ranged from 21-36ma, within M-B specs of 50ma he wrote. I have to think he would read the meters correctly or maybe the test unit just spits it out. There sure seems to be a difference between them and what I'm reading.
 

BobLLL

Member
But didn't they initially see a bigger drain, then it was gone? Perhaps intermittent then, and getting more permanent now. I have no idea, though, what might cause that.

By the way, do you have a negative terminal disconnect for your coach batteries? If not, you should charge them once a week or they will run down too.
 

Inspector

2012 Roadtrek Agile
Yes, you are correct that they initially saw a out of spec draw but later said it was OK and it could have progressed like you said. I appreciate the tip on the coach batteries because I checked them today..12.5v. Question, if I reconnect the separator ground wire, will the coach batteries try to charge the depleted starting battery, dragging them down?

I really appreciate the help everyone is giving me as I have to rely on my wife for most checks/tweeks or the dealer, so it's a slow process. It is frustrating for sure

Steve
 

Inspector

2012 Roadtrek Agile
I will do that, I suppose I should leave the separator disconnected until I find the drain problem?
Thank you very much,
Steve
 

autostaretx

Erratic Member
Just out of the dark: do you have a trailer hookup on this thing?
If you have one, the NCV3 "snoops" the trailer wires every so often to see if the attached bulbs are OK.
Folks who put LED bulbs in their trailers report seeing the lights blink at times, even with the key out of the ignition.
So if you had one, that's another (completely left field) system that could be causing unwanted current flow.

As for "what happens if i attach the separator ground?" ... use the Voltmeter, Luke.
(but if you put a shore charger on the house side, it may well trigger it to join)
((why i really prefer the "driven relay" style of separator vs voltage-sensitive. Luddite 'old school'))

--dick
 
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BobLLL

Member
All Agiles come from the factory with trailer hitch, and a continental tire carrier with an extra tail light in the tire carrier cover, because the carrier partially obscures the left tail light. The extra light is plugged into the trailer outlet. The bulbs in the extra light are incandescent.
 
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BobLLL

Member
Steve, I wish I had something more to offer, but what I think I would do is monitor the situation to see if the drain is constant or intermittent.

Reconnect the starting battery, charge it up as best it will for 12 hours, disconnect the battery, and see if it runs down as quickly as it did before. If so, the drain is pretty constant and maybe it will still be there when you take to the dealer.

Maybe ask around town for an independent shop with a good rep for electrical diagnosis.
 

BobLLL

Member
I have an adapter that allows me to connect an ordinary extension cord to the shore power connector on the rv. So I can plug into a garage wall outlet that is too far away for the 30 amp cable. And it is a lot easier handling a regular extension cord than dragging out that heavy cable. This allows me to easily use the perfectly good charger built into the rv to charge both batteries at the same time. Just plug it in for a couple of hours, and its done. The charger only draws a few amps through the cord, so don't need a 30 amp cable. Just don't try to run the air conditioner or microwave at the same time through the extension cord.

The adapter is a Conntek 30222. Looks like this:
shore power adapter Conntek 30222-YW v2.jpg

You are not likely to find it in a local store. Can order it from Amazon and other places online. About $25.
 

Inspector

2012 Roadtrek Agile
We don't have a trailer but good to know, we just have the spare tire continental kit as BobLLL mentioned. I'll re-connect everything and see what happens, if the drain is consistent it's a lot easier to track like you said. If I find it I'll post back.
I liked the simplicity of the old diode chargers back in the day, they had their faults to but I don't remember to many issues.
I want to thank you gentlemen for all the guidance and time you have given, I sincerely appreciate it.

Steve
 

autostaretx

Erratic Member
If you have a trailer hitch, then you have the MB trailer module ... which DOES add a fuse to the system for its own power.

It's listed in my wiring diagram as "Fuse 4 in Fuse Block 3" which is 7.5 amps.
I'll see if i can locate which block is #3 in the fuse list (done).

Found it, driver's seat-side panels, upper left, 4th in from the left:

TrailerFuse.png


--dick
 
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Inspector

2012 Roadtrek Agile
BobLLL, somehow I overlooked the post about using a lighter duty extension cord and RV adapter. The charger that is onboard the Agile is the one you were referring to? Sure would beat the underhood nonsense. Does the monitor power switch have to be on to charge?

Autostarext, thanks for the information on the trailer monitoring circuit, I didn't know about that one until you brought it up, thanks!

If I connect my meter for measuring drain, I should be able to identify the offending circuit by pulling fuses one at a time, barring there aren't multiple problems.

Thank you!

Steve
 

BobLLL

Member
Steve: No, the switch does not need to be on during charging. Did you get that cigarette lighter voltmeter we talked about in another thread? It is a good idea to use that to confirm the separator has engaged and the starting battery is getting a charge along with the coach batteries. The Tripp Lite charger is rated for 45 amps, but the resistance of the long wires between the charger and the batteries reduces the typical charge rate to about 25 amps by my measurements. Even so, the charge cycle can happen pretty quickly unless the batteries are deeply discharged. The charge continues at full rate until the voltage rises to about 14.4, then switches to "float" mode at about 13.4 volts. It will continue in float mode as long as it is plugged in. A constant charge at 13.4 does not hurt the batteries, but probably not good to keep plugged in all the time as the separator gets so hot it seems like it may cook itself. I don't think the separator is designed for constant duty.

Bottom line: Charge at least once a week (maybe more often if your high drain situation continues- best to not let the voltage drop below 12.5). Leave it plugged in an hour or so, then if the cigarette meter has settled around 13.2 to 13.4, unplug the shore power. Also, the meter can work loose in the socket, so if the reading seems nutty, shove it back in and twist around a bit to make a good connection.

This system has worked well for me for almost 8 years.
 
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autostaretx

Erratic Member
A constant charge at 13.4 does not hurt the batteries, but probably not good to keep plugged in all the time as the separator gets so hot it seems like it may cook itself. I don't think the separator is designed for constant duty.
Given that warning, i'd buy a different separator (or, if it's a relay-style, perhaps add a resistor to the coil circuit ... but if the problem is heat generated by and/or damaging the heavy-current contact points: buy a beefier one)

--dick
 

BobLLL

Member
Yes, I replaced mine with a Blue Sea latching relay, which does not keep the coil powered except to latch on and off. But I think Steve's project list is full right now. And Blue Sea units are not cheap, and involve some drilling for new mounting holes in the firewall. There is plenty of discussion in older threads on here, and here is a link to installation instructions by RT.SS:
http://roadtreklife.blogspot.com/2015/12/battery-isolator-upgrade-to-blue-sea-ml.html
 

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