Chassis battery not charging

russncath · 03-30-2019, 08:51 PM

So, just swapped out the 12 volt house batteries for two new 6 volts the other day on my 2015 Windsport S.Took the rig to a campsite for the wife to camp tonight, went to use the levelling jacks,with the engine running, low voltage message came on....quickly checked the inverter, says 12.6 volts. Plugged the shore power in and tried the jacks, ok now, and voltage shows 13+, which tells me the converter is working..Looking like the alternator is not charging? Had no time to check anything today. Seems like too much of a coincidence for the alternator to pack it in right after a battery replacement...Any ideas? Any relays, fuses etc that could have popped and cause a no charge situation when not plugged in?. Thanks for any and all help !

javelin · 03-30-2019, 09:06 PM

Hi, do you have a voltmeter available? If yes put it on the chassis battery with engine running and see if your alternator is working OK there. Next leave the engine running and put the voltmeter on the coach batteries (with no shore power). Is the alternator charging the coach batteries? So, if the alternator is working to charge the chassis battery OK but not the coach batteries then it could be the interconnect relay is not closing to connect the alternator and chassis batteries together…….or fuses in that control circuit. I don’t know which battery control system you have, but a generic schematic is attached that may help you visualize (it happens to be a BIRD by Intellitec). You could also test the interconnect relay (also called the emergency start relay) by running the engine and closing the emergency start relay; (you should hear it operate); then measure voltage on the coach batteries for 13.1 or higher.

javelin · 03-30-2019, 09:37 PM

Oooops, I should read my text before posting....the interconnect (or emergency start) relay connects the chassis and coach batteries together....I said alternator and chassis.....my bad.

Beau388 · 03-30-2019, 10:20 PM

2X

russncath · 03-31-2019, 01:53 AM

Thanks , I will check this out tomorrow and let you know the outcome

russncath · 03-31-2019, 06:47 PM

Well, I have 14.5 volts at the chassis battery when running, but only 12.6 at the house batteries...Had the wife hold down the emergency start button while running, and still only have 12.6, can feel the relay clunking when the button is pushed, so I guess that tells me it is working...It does have a bird relay mounted in the battery compartment also, the wires head off into a harness that leads somewhere!! Any more ideas?!!

javelin · 03-31-2019, 07:01 PM

So you have proven that the alternator is working and is charging the chassis battery OK. You seem to have proven that the interconnect (or emergency start) relay is operating (makes noise at least) when the emergency start button is operated by the DW…….but that relay operating is not connecting the chassis battery to the coach battery as it should. So I would suggest finding the interconnect (emergency start) relay and verify the contacts are good on it (might be burned or damaged) and also that your power cable connections are good on both sides of the relay as a start.

russncath · 03-31-2019, 07:07 PM

The emergency start relay is right in the battery compartment, so easy enough to check. So really, there should be 14.5 volts on one side of that relay if I am understanding you correctly, and for whatever reason, only getting 12.5 out the other side?..
.

javelin · 03-31-2019, 07:18 PM

I should have mentioned that the schematic I included in a previous post shows the "isolator" relay which I call the interconnect or emergency start relay.....just to clarify.

Also I suggested checking the tightness and cleanliness of the power connections on that relay first to make sure this trouble is not a bad connection first. If all is clean and tight and you still see 14+ volts on one side of the relay and only 12.6 volts on the other side when the relay is operated (closed) then the relay contacts are bad and it probably needs replacement.

javelin · 03-31-2019, 07:34 PM

When the relay operates it closes its main power contacts which should directly connect the coach and chassis batteries + terminals (via cabling) together. So you should then see the same voltage measured to ground on both sides of the main power terminals of the relay...which would be 14.5 when alternator is charging (engine running) and more typically 13.1+ when the converter is charging the batteries (via shore power/engine off).

russncath · 03-31-2019, 07:49 PM

Well, I think that relay is the problem..wont make a sound half the time now and have 14.5 on one side and only 12.6 on the other, connections all appear ok so, I'm thinking new relay. Nothing special about the relay is there, could use something like a Ford starter relay? Thanks alot for your direction!!

russncath · 03-31-2019, 08:14 PM

Lordco has a continuous duty 85 amp solenoid that should work

javelin · 03-31-2019, 08:19 PM

Hi, well I would suggest trying to match it with existing part number if possible....safest and less need to change wiring if required to accommodate a different replacement part. In a short term pinch/emergency you could probably use a high amp Ford starter relay. It boils down to current/voltage rating of the contacts and how long the relay stays energized (could overheat if it is intended for short duration use like a starter relay). These are not latching relays.

russncath · 04-01-2019, 01:09 AM

Well, swapped out the relay and installed a new one, all is good now. Voltages are fine. Had a Trombello relay in it, spelling? That is a manufacturer name so, I think the one I installed will be fine. Mounting of the connecters was a little different, but worked ok. No mention of amperage ratings on the old solenoid, but 85 amps should be ok I would think? Thanks again for your help!!!

javelin · 04-01-2019, 02:45 AM

Glad you got it working. As a side benefit you also just fixed your emergency start function if you ever need it (coach batteries starting the engine if the chassis battery fails).

Judge · 04-02-2019, 11:19 AM

Somewhat related to the topic title.....

I just installed this device yesterday on my Outlaw 29H. Apparently it is / was standard on Winnebagos but works on any motorhome where the shore power does not charge the chassis battery. It uses the house batteries and acts like a battery maintainer without using a 110V unit.

Ultra TRIK-L-START Starting Battery Charger/Maintainer

The install was very easy. I actually installed mine inside the cab on the same panel as the Emergency Start switch so I can easily see when it is is Maintaining or Charging the chassis battery.

I connected it across the emergency start relay and added this 15amp automatic reset circuit breaker per the recommendations when adding additional wire length.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Now when its sitting for large periods of time, the chassis battery will remained charged.

lwmcguire · 04-02-2019, 12:24 PM

Quote:

Originally Posted by russncath

Well, swapped out the relay and installed a new one, all is good now. Voltages are fine. Had a Trombello relay in it, spelling? That is a manufacturer name so, I think the one I installed will be fine. Mounting of the connecters was a little different, but worked ok. No mention of amperage ratings on the old solenoid, but 85 amps should be ok I would think? Thanks again for your help!!!

The Trombetta was at least 200 amps or higher

Be careful you could overheat the replacement if you hold it in for a run down battery situation

javelin · 04-02-2019, 01:05 PM

That's why I always recommend replacing with like part number (assuming the part is OEM). Attaching the Intellitec relay part numbers and ratings for comparison. Also sometimes ordering items off Amazon and eBay "may not" always deliver the equivalent goods....so be careful.

russncath · 04-02-2019, 01:27 PM

The 85 amp is all I could get on a Sunday, to verify this was the issue.. will be replacing it shortly with a 200 amp, which I see is their largest one. Will check and see if the part # is visible on the old one..Thanks!!

PictureTheSouth · 04-06-2019, 08:07 PM

FWIW, we have a similar issue on our '15 Windsport 27k. So far, we haven't tracked it to any specific power or battery issue. Our leveler panel constantly goes into a "low voltage" or "return for service" status. Had service techs look at it last fall, and all they did was reset the panel. It works like a charm with no errors at all as long as we're on shore power; but wouldn't trust it on coach or generator power.

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