House battery dead but system works with engine on

[danbr]

A couple of other comments . . . .


- By far the fastest way to kill a battery is persistent under-charging. Once it's sulfated, a new battery is in your future :-(. But having it go low and stay low a few times won't degrade your capacity much.

- A 10A charger is pretty small - the recommendation on the marine side (which is what I'm familiar with) is 20-40% of the AH capacity. We have 200AH house batteries in our SMB which equals 40-80A of charging capacity. But it doesn't matter at all until you hook up the shore power system :-)
- The alternator size matters, but most auto alternators should be more than up to the task.
- I would STRONGLY second the recommendation for a deep-cycle house battery instead of the dual capacity one.
- Can you check the "resting" voltage? ie, leave the van overnight (or for a few hours at least) with the house battery _disconnected_, and then check the voltage? A new AGM battery should be at 12.9 volts when it's fully charged. My guess is that without the van running it will be very low.


Last note: Interstate sells through MANY distrubutors, but they also have their own battery centers . . . including one in Brooklyn.


Dan

[REF]

Look around for a batteries plus, they carry rebranded East Penn/Deka batteries as Duracell RV/Marine deep cycle AGM, they’re sealed units and can better withstand extreme temp changes and discharges without damage. You’ll want to match the size, if it’s a big honker, most likely a 4D.
You’ll probably want to address the charger issue by getting a bigger charge unit, or get a charger/inverter unit so you don’t keep running into the same issue.
I can’t remember if you mentioned if you have solar or just the pre-wiring, add it if not, it’s the best way to keep things topped off and your battery happy if your rig sits outside between trips.

[HIGHCOUNTRYMIKE]

I had a similar situation with house battery. With engine running everything worked. Turned off engine within a few seconds the house lights, frig stopped working.
It was the house battery which when I checked records indicated it was plus 3 years old.
2003 E350 EB 4X4 SMB HIGHCOUNTRY MIKE

[Nathandeuel]

See the attached images. I found the breaker that had been tripped, likely by the local mechanic here in the Midwest who was working on addressing why my fuel tank is funky when filling up. Bad news: Fuel tank still cranky when fueling up, requiring me to drip gas in slowly. Good news: House battery system now fully operational.

Question: Local mechanic was concerned that the wires around this breaker seemed "green." He advised sanding and sealing with liquid tape. What do you guys think? THANKS

[Scalf77]

So yes, your connections are getting corroded. I would clean them up and apply dielectric grease at a minimum. The shrink tube looks to be non adhesive type, and thus that oxidation is now working itself back up the cable. What is the distance from the circuit breaker to the battery? I expect that it is the main breaker from the house battery. It should be close to the House Battery.

On a side note you have a Blue Sea #7611 BatteryLink Automatic Charging Relay. One particular feature of this unit compared to other ACR's is no "low voltage lockout" The majority of ACR;s have this feature, which would have meant the alternator wouldn't have worked either.

It is always good to disconnect your house battery the start battery system when taking it to a mechanic, as they many times will disconnect the battery if needed when servicing. They don't like surprises either.

I would also check the gouge size of the offshoot wire that goes house systems, and what possibly circuit protection provided. And the installation of a battery monitor Victron 712, Balmar SG200, or one of your choice. This would give you a voltage reading at the battery, helpful in diagnosis of issues, and aid in your battery health.

-greg

[daveb]

Yeah I agree with Greg. Also make sure the wire under the crimp is clean and tight. Many times the corrosion can be under the pressed connection of the lug itself and you might have to install a new connection.