Minivan camper electrical system will this plan work?

[ccbreder]

Deka, made by East Penn are marketed here as Duracell. There are two, GC-2 @ 215 AH and EGC-2 @ 230 AH. The flooded cell battery are excellent and recommended. At this time, East Penn has not quite got the best AGM.

 

[Optimistic Paranoid]

At this time, East Penn has not quite got the best AGM.

It's interesting.  At one time, AGM were very much a specialty item, made by only a few manufacturers.  Now everybody is jumping on the AGM bandwagon, or trying to.  Even Trojan now has a line of AGMs . . .

 

[SternWake]

 At this time, East Penn has not quite got the best AGM.

yea, rated for 375 cycles to 50% discharge is at least honest.

Northstar and Odyssey claim 800 cycles to 50%, LifeLine 1000.

the trojan t-1275 flooded battery is rated for 1200 to 50%

This of course assumes the batteries are recharged properly after each cycle.

the true test of an AGM is when it is not charged correctly, how much capacity it loses. the better AGM will regain a good portion of capacity when recharged correctly after much abuse, the lesser AGMs no so much.

The Deka intimidator AGM apparently did very poorly in PSOC cycling compared to the other AGMS.

Partial state of charge cycling is starting the discharge cycle before the battery has had a chance to return to near 100%, preferably 100%.

Lead acid balloons need their skin stretched to their maximum often, or it shrinks, gets crusty and full of pinholes.

If filled often to their full capacity, they can provide many cycles, if not, then it is just a much shorter amount of time before capacity loss becomes noticeable and inconvenient, and then expensive.

Hail Mary recharges on an abused battery usually yield, at best, temporary improvement.
Usually the equipment and knowledge required to do a hail mary recharge, can keep the next battery much happier.

Best to not to have to learn the hard way, but that is how things are learned the best, it seems

 

[evoscot]

Not the Ideal battery by a long shot but I scored a matching pair of group 27 deep cycles today for $32 (the core charge).  I haven't tested or tried to charge them but they both had high 12's for voltage on a simple carbon pile 100 amp machine we have at work.  If they get me through the set up and testing phase of building my van I can use them for cores on my golf cart batteries in the spring.

My fridge showed up today (3 days late)  It's super quiet and it fits in my spot so I'm happy with it.  It's way quieter than I expected it to be.

I'm going to add new pictures and another video on my build thread.

 

[regis101]

Not meaning to drift off topic but I copy/pasted this from page two and am wondering how, considering the voltage can vary by a couple for battery charging.

*All these are RV converters, meaning they can both power DC loads as a power supply, And 3 stage battery charge without getting confused like a regular smart charger with alligator clips and a sexy plastic exterior and a bunch of lights.*

Is there some type of sensed equilibrium from the converter to/from the battery while the 12v appliance side is drawing also?

Sorry, and thanks

 

[ccbreder]

I have a ProNautic 1240P. It is a three stage charger with temperature compensation. Extra smart charger. It has a setting to use it as only a charger or to use it as combination charger/power supply. As power supply, it charges/maintains the bank, but will adjust output up to handle any loads.

 

[SternWake]

Is there some type of sensed equilibrium from the converter to/from the battery  while the 12v appliance side is drawing also?

The regular smart charger is expecting battery voltage to rise as it applies current.  If voltage does not rise, or a big load actually drags down voltage, the regular smart charger thinks there  is a problem and shuts down. 

The RV converter is a power supply designed to seek and hold a certain voltage, applying as much as it can to attain that voltage.  It does not know how much amperage is going into the batteries vs into powering DC loads, and does not care.

With a 45 amp converter one can apply a 45 amp DC load and switch it off and the converter will just return to the max voltage at whatever stage it is in.

They all have slightly different algorithms as to how they decide to go into boost ot regular or storage modes.

None are perfect, everything is a compromise, and nearly every automatic charger does not hold absorption voltage long enough on a deeply cycled battery.  This amount of time is highly variable, so they are basically making a lawyerly approved stab at getting to 95% or so and flashing the green light to soothe the human despite the battery not being truly fully charged.

Flooded battery owners would have less faith in that green light if they were to dip a hydrometer after a deep cycle when that green light illuminates.

AGM owners need to be able to measure amperage required to hold absorption voltage to determine full.

I use an adjustable voltage power supply as a charger, and I choose the absorption voltage and how long to hold it, or I choose the float voltage, and my battery is regularly returned to a true 100% state of charge and has ~400 deep cycles on it and is still performing very well.

That last few % of charge takes a long time to accomplish and has a huge effect on total number of cycles the battery can deliver.  As the battery ages that last few % take longer and longer and if it does not get there, capacity will drop off more and more rapidly, and at some point, will only then be noticeable to the average observer.

So when one plugs in a regular smart charger on their abused house battery for a while and sees that green light and thinks all is well. They need to unplug charger, disconnect it from battery, load battery to reduce voltage to below 12.8v and restart it.  Lather rinse repeat, and each time it will get the battery closer to a true 100%.  verify with hydrometer or Ammeter, but do not put any faith in that blinking green light.  It mocks the human who believes it.

If one does not want to babysit their charger and will be plugged in for a few days, and the charger has an AGM setting, choose this, even on a flooded battery.  The AGM setting should float the battery at 13.6v and will continue to charge, albeit at a much slower rate than at 14.4, but certainly faster than the 13.2v that it would choose on the flooded/normal/wet battery selection.

but again a smart charger left plugged in while DC loads are being turned on and off will likely go into fault mode and shut down, unless it has the power supply feature.

My schumacher sc2500a on the 12 amp setting would not shut off when my fridge cycled on and off, but voltage would dip to 12.9 when compressor turned on then climb back upto 13.6, and then shoot to 15.6 when compressor shut down.  it would take several minutes for voltage to lower back to 13.6 ish, and that time at 15.6v was abusive and unneeded and would make the battery use more water.

 

[regis101]

Good reading there. Thanks.
So it seems that if using a modern RV converter, all should be well to t-tap the converter out put with one lead going to the battery(s) for charging and the other going to the 12v fuse panel for coach accessories as long the converter is properly sized.
I am not able to calculate the battery charging amperage draw vs known coach load to be able to properly size needed converter.
Again, I hope this is not drifting. With regards to the OP, I think my inquiry is part of the equation.

 

[evoscot]

Good reading there.  Thanks.
So it seems that if using a modern RV converter, all should be well to t-tap the converter out put with one lead going to the battery(s) for charging and the other going to the 12v fuse panel for coach accessories as long the converter is properly sized.  
I am not able to calculate the battery charging amperage draw vs known coach load to be able to properly size needed converter.
Again, I hope this is not drifting.  With regards to the OP, I think my inquiry is part of the equation.

I'm all about learning this stuff and your question was good

 

[SternWake]

The house fuse panel, I would wire it directly to battery (+) and have a buss bar mounted next to  panel it for the (-).
 The converter outputs are Kind of sloppy being the crush stranded wire under a set screw, and thick wire puts a lot of stress on the converters output terminals. I'd not want the house fuse panel run through the dc outputs on the converter.
Thick wire is needed even at a short distance otherwise the automatic converter will see 14.4x but the battery could be 13.9v. They do not employ separate voltage sense lines to account for voltage drop, so it causes them to charge slower and if voltage drops at converter output, it slows even more.
Mount converter close to battery.
Fuse to protect wire size employed.

 

[regis101]

I like the idea of keeping everything close together.
I'm thinking then one wire from converter (+) to the battery, hoping out put is fused at the converter, then add auto rest circuit breaker at battery and continue that wire to a house fuse panel. Thus, instead of a t-tap with having one lead go far to the right and the other go far to the left, (battery and house fuse panel), The simpler way is to put the battery between the converter and house fuse panel?
I googled , RV wiring diagram, and got hundreds of pictures. Yet they all seemed a bit different. sheesh.

That you for the continued knowledge.

 

[SternWake]

Designing the circuits and layout of the appliances is personal thing. Just plan on thick wire, shortest practical wiring distances and minimal connections. Converter feeds battery, battery feeds fuse block, converter feeds fuse block indirectly through battery.

Some of the wiring I've seen in manufactured RVs is totally convoluted and asinine so don't hold them in high esteem.

Properly terminating the thicker wires with thick walled ring terminals or Automotive post clamps is where one needs to step up with proper tools like a hydraulic crimper, or have them made at geniune dealz or similar.

Do not buy Auto parts stores battery cables/wires. they are SAE gauge which is 8 to 12% thinner, and they use steel ring terminals which rust and are highly resistive and not a good deal anyway.

If bad crimps are made then you will get to redo it after it causes some sort of failure.

 

[ccbreder]

Most RV complaints are related to the converter over charging the battery. I still recommend a marine type smart charger. Set as a power supply/batery charger. Take all your loads from the battery. Charger cables only to battery. Use heavy enough cables to not have much voltage drop. Get your cables here; http://www.genuinedealz.com/custom-cables/custom-battery-cable-assembly
The only charger I would recommend would be by Sterling ProCharge, or ProMariner ProNautic.
And don't forget fuses, fuses, fuses.

 

[SternWake]

BS.

Magnatec converters from the 80s and 90s were single stage chargers that would charge too slow, and if left plugged in, would eventually overcharge the batteries.

Nobody in their right mind would buy this dinosaur for charging today. And no van dweller would plug in long enough for 13.6 to dry out their flooded batteries.

The other complaint is the WFco converters that come standard in many rvs today. They usually never go into boost( 14.4) mode and are a waste of time to charge the batteries on generator, and they have a high failure rate.