House/chassis battery issue

As I understand it the problem is not that unusual and is likely due to leaks in the high pressure fuel system. I don't think there is any danger to the engine just an unusual long crank when cold as it gets the fuel pressure high enough that the ECU allows it to start. It is a late '07 motor and has 124k km so about 77k miles on it and runs well otherwise. Faster cranking speeds (from fully charged batteries) do make a difference - thus the idea of keeping the batteries charged. Because I have a solar system on it I can use it to always keep the batteries charged but needed a way to include the chassis batteries which the new interconnect takes care of...

Off topic here but have you done much research on the Ford 6L diesel of that vintage?They can be a fantastic motor but many are major problem prone.There is a whole industry dedicated to fixing these inherent problems.While costly,maybe cheaper than replacing a blown engine in the middle of nowhere.Google Ford 6L diesel bullet proofing. How many miles on it now?

No. I have added a separate relay. I do normally use the dash emerg start tor cold starts as it provides a better cracking rpm that reduces start time on the 6.0 diesel. This issue is related only to my motor and would not apply to most. I am hoping that the ability to keep both sets of batteries charged helps with winter storage.

Dash interconnect
Do you mean the Emg jump start button ?
That is there to Boost the chassis battery from the house batteries,
If the chassis battery is too low to start the engine

To complete the picture I have now added my own version of a trik-l-start - essentially my own interconnect relay that I can control with my on-board data system. Once the house batteries are charged (in float) I connect the batteries and let the solar charge the chassis batteries. Exact logic to be determined but it seems to work fine. I plan to use this approach to maintain both sets of batteries over the winter although the effect of heavy snow may need to be considered.

Glad to hear you found that before spending bucks casing ghosts. Fingers crossed that's it. :C

Problem has been resolved. It seems that the dash battery interconnect button must be pressed with the key off. I was pressing it with the key on just before turning to start! My solar system keeps the house batteries fully charged so with the button I get good cranking speed and a start in maybe 2-3 seconds rather than 5-6 seconds. I will leave as is for now but will continue to look for the current leaks. Thanks to all for the discussion.

I believe you said your batteries were new. It is possible you might have gotten a dud. I had that with one. I also currently have no radio b/c something in it went south and was causing a pretty quick drain. Definitely have an electrical check done. Could be a simple/cheap fix and nix having to do anything further.

ramsaymike wrote:

And somewhat related to the last comment it seems that the house batteries are under the entry step (2007 Coachmen Concord M275) while the chassis batteries are further back in a compartment. I thought it should be the other way around and actually took the unit back to the dealer to confirm but was told that it was correct. It seemed odd to me. Can anyone confirm that this is correct?

On a class C motorhome, which this model seems to be per a google image search, the chassis battery would be under the hood in the front. More generally, I'd generally expect the chassis battery (or batteries) to be in fairly close proximity to the engine on any motorhome, though I'm sure there may be some makes and models that have them in strange locations. House batteries can be most anywhere; under the entry steps is one quite common place.

ramsaymike wrote:
Well I think the Trik-L-Start is a DC-DC trickle charger...no?

TLS is a combiner. When it senses voltage high enough to charge it will combine the batteries electrically at that charging voltage and allow up to 5 amps to pass through.

Typically an actual DC-DC charger is a bit different. A DC-DC charger will boost the voltage to give a faster charge. However this could drain the supply battery to 10 volts or less. A DC-DC is designed to boost voltage from a continuous power source to charge a battery at the end of wire that is a bit too long and too thin for proper charging. Also since the DC-DC charger creates a differential of voltage you could create a charging loop with multiple sources. Anyway this is not really what you need.

Trik-L-Start will work great.

However you may also need to look into why the battery is getting drained so fast. This will take some real time and deliberate investigation to isolate the issue.