The mystery of the slowly dying batteries

[daveb]

Greg's correct. Almost all battery manufactures will tell you to charge their AGM's as wet cell batteries. It is all about the voltage the each type of battery needs. VRLA batteries are AGM's and you can go to the manufactures web site to check. Some AGM's like a slightly higher voltage, some prefer a lower setting. You need to match up the closest voltage the charger puts out for the longest battery life.

[mtbjonny]

Hi Dave & Greg - Thanks for the clarification - I'm certainly not going to argue with two experts here!

I'll post back when I get more information from further experimentation.

Thanks again!

Jon

[boywonder]

Originally Posted by mtbjonny

I'm going to keep the van & house separated. In a couple days (maybe next weekend), I'll try & turn it over.

Additionally, when I pull the batteries for load testing, I'll check to see how the aux battery on my van is configured & if there's a relay or something that I need to take into account.

Great plan.....FWIW my house batts are AGM and my starting battery is a Motorcraft wet cell and they are living happily together...at least for the last year and a half....

[ShuttlePilot]

I support the plan daveb is recommending also. My van had crazy phantom loads and charging for that mater when I got it (Used). The first owner had a pretty elaborate A/V system installed when new in 2006. Then he said it was stolen and he had a local car stereo shop put in a new one then he upgraded it with another stereo shop, a lot of "professionals" in the vans wiring.

So when I got the van in order to try to figure out what was happening I started by separating the batteries and clearly separating, as in disconnect one cable from the combiner. Then disconnecting loads starting closest to the load either at the fuse or power wire and working my way back to the batteries looking for the drain to disappear. What I found was I had two relays left over from one of the old A/V system in the wall that were stuck in the on position (always warm). And worse a cross connection between the house bank and the starter bank though the head unit via the SMB stereo switch. I have since removed all old wiring and rewired/fused the van much more simply.

I'm not saying your issue is in the stereo just that if others have been in your wiring what they worked on could be where the issue is. And separating all the players and even reattaching loads one at a time will likely show where the issue is. Even if its a chaffed wire grounding somewhere.

Finally I will echo that when it comes to charging and discharging a battery try to provide as close as possible exactly what the BATTERY manufacture states. Some times I feel people forget that all the equipment like solar, solar controllers, chargers/inverters are there to support and feed off of your battery not the other way around.

FWIW: I have two starter batts (6.0 PSD) AGM and house batt AGM. But flooded starters would be fine with AGM house.

[dhally]

Originally Posted by mtbjonny

Yes. It's a spring loaded switch. And when I released it stayed at 12.8V. Is that normal, considering there's no voltage on the van (van battery was disconnected).

You might want to check the manual for your separator, but I think it should only close when the emergency button is pushed in, or as suggested above it might stay closed for a few seconds longer.

[dhally]

Originally Posted by mtbjonny

Yes. under the side door step. There's a topic on this battery:

viewtopic.php?f=14&t=1917

Info in this tread suggests that the battery under the side door step is just for aux van power (trailer hitch relay). I may have jumped the gun saying it was attached to the alternator. I re-connected both van batteries & started the van up (with the house physically disconnected from the van). Checking the voltage on the battery inside the engine compartment shows 14.4V (as expected - alternator is charging it). But the battery underneath the side door step shows 12.8V (with the van running), so I'm not sure what it's connected to? How would it get charged if it's not getting charged from the alternator when the van is running?

The battery under the step might be dead. With the van running, I agree there should be voltage present. I also agree to disconnect it, since you aren't using it for anything. Unless you have a trailer that needs power when the van isnt running.

[Viva]

As Shuttle Pilot and others have mentioned, what I would do for the inverter dip switches is look at two things:

1) Look up your house battery(s) manufacturer's specs for the voltage they want to see in absorption (sometimes called acceptance) stage and in float stage. Then look at the inverter manual and see what it "gives" the batteries in the two different stages at the different battery type settings, and see which one matches up better. Use that one.

2) See if your inverter has temperature compensation available. If it does and it is hooked up, great. If it does and it is not hooked up, buy the optional temp sensor and hook it up. Here is why I say this: The voltage specs for absorb and float? Those are always given "at" 77º F. As long as your batteries are at 77º F, all is well. I find that mine rarely are, since my rig is not like a house that is kept at a steady temp (my batteries are inside). Even if it is 77ºF outside, the batteries are often still at 50º because those big hunks of lead get cold overnight. If you can (and do) use the temperature compensation, it will "adjust" the charging voltages to compensate for the amount you are away from 77º. This means more voltage when the batteries are colder, and less voltage when they are warmer. I figure if you are going to the trouble to set specific voltages because your batteries need them for best performance/lifespan, why have them only hold true at 77ºF?

If you ever replace your inverter/charger, two things to look for are custom programmable voltage points (so you don't just have to choose between two pre-decided settings) and temperature compensation.

[mtbjonny]

Hey everybody - thanks for the support here! Couple answers:
- Yes the inverter has a temp sensor for compensation & the thermocouple is taped to the side of the battery. Is there a better place on the battery to tape it to? OK with tape or do you guys go full on with thermal grease?

The house battery is a lifeline battery & if it's bad, it's still under warranty.

I'll remove the aux battery from the loop - but really want to understand what it is! Anybody actually know what it's for on the V10 E350s?

And Shuttlepilot - your process is exactly what I'm trying to do - so that's good! I hope I find something as (seemingly) simple as an old relay. We did have a stereo amp put in along with everything else (at Sportsmobile - it's subcontracted out to a 3rd party - I assume he was 'good' but i'll put it on the list of issues to check for). May need to check that out too. One issue I'm having is the load (amps) seem to vary over time without good reason. Is there a specific voltmeter brand/model you're using? Mine has a 10A scale, but I'm not sure if I trust the accuracy of these things (particularly for $30!).

Dhally - my emergency switch kept closed indefinitely (more than a day) after I hit it. Specs say that it should be closed when the battery voltages are within 12.65 --> 13.??V (Can't remember the exact #).

[Scalf77]

No thermal grease needed, it just needs to be taped to the side. I think all purpose duct tape was used on mine but it has been a while.

The switch input for the Blue sea 7620 works pretty straight forward, if it is left open the ACR is in automatic mode, connecting and disconnecting based on voltage level and time. If you tie it to 12 volts it combine the two batteries, as long as their both above the cutoff voltage of 9.7 volts. This also disregards if you are using the start isolation circuit. And if you ground that wire it will disconnect the two batteries and remain disconnected no matter what the voltage of either battery.

I have never seen a V10 that had the Ford extra battery, I am pretty sure it is only supposed to be tied to the starter, when it is running. There are various fuses and links that you have to make sure are in place. I believe Darryl above points to a good post on it.

I am not sure what your model solar power unit is, but it does not sound to me like anything you have as long as working correctly should be causing you issue. While I believe that combining AGM's and wet cell starters can cause early life failure on your starters, it takes time. The failure mode is predicated on the fact that wet cell will loose water if on extended float cycles. This would be more of a problem if you plug in all the time, a lot less if you just use solar. So moving to AGM starters or disconnected the ACR when you are charging the house would prevent that.

So separate the house from van ( check if you really need the second van battery?)I agree with shuttle pilot, the stereo system is easy place where things can get crossed up. You're $30.00 voltmeter is fine for voltage measurements, but I would not count on if for accuracy of if looking for a small parasitic load.

Happy Hunting

greg

[ShuttlePilot]

mtbjonny when you say the load amps seem to vary (I'm assuming up and down) over time for no obvious reason my mind keeps thinking a circuit is ever so slightly grounding somewhere. I've seen it happen often on heavy equipment where it would start during the week but after sitting over the weekend it wouldn't start. It's usually easy to find which circuit has the draw but then finding where it's grounding has often been the frustrating part. In your case it's different in that its proving difficult to find the circuit.

I'm looking forward to the "found it" post.

-Eric