Expedition Power Subsystem Diagram for Feedback

[Kiomon]

hey guys,

Need some help from the electrical gods. We are preparing to film 36 non-profits across europe and africa traveling overland in a VW Vanagon Syncro. You can find out more about us at fmfac.org if you are interested. I am laying out the electrical system, and i need some help. I am laying out the "subsystem" and then the circuit separate.

Here is what i am trying to accomplish. I want a battery bank consisting of a main and a smaller aux. that can both be charged by solar, engine (alternator), and shore power. I will be laying out all of the circuits and gear/ appliances in another post for feedback, but want to nail this first. For reference the engine as a 120 AMP alternator.

Here are some considerations
- Both of the house batteries are AGM and i want them to be properly multi stage charged
- I size up the solar charger because there may be another panel that can be installed and then packed away during travel. But the 215 Watt will be permanently mounted on the roof.

Here are my questions
- The 25AMP Magnum Battery Charger is intelligent and multistage which i like, but its only 25 AMPs. Can i get more charging "intelligently" from my alt with another device?
- You will note nothing is connected to my positive bus bar. Can move all of the positive connections from my battery to the positive bus bar (leaving the "sensors" direct to the battery)

Would love some feedback, i am still learning, and while i know i should go to a pro and pay for all of this to be installed, i really want to learn and do it ourselves, so we can actually afford to make this happen!

vanagon-electrical-system1.jpg

[UK4X4]

Just a quick look,

the combiner charger does not mention being able to charge an AGM battery- there is a diferent regime for diferent types of batteries- it looks to me like wet cell only

You have 3 diferent types of batteries, normally batteries don't play nicely together if diferent types.

Looks to me to be very complicated and could be simplified - but don't have time right now

Look at a Few RV setup diagrams

start battery and the optima can both be used on the combiner
together and will play nicely

having start and backup

Solar and electric with the house batteries can be looked at seperately

take a look at the xantrex SW charge controller too


DUH optima is AGM. ignore some above - still no time !

[Kiomon]

Will definitely double check on the combiner and charger. I thought it was AGM compatible, and fully adjustable even to stage voltages.

And definitely like the idea of simplifying so i will check out some RV diagrams. Right now i have just seen simplified diagrams.

[dwh]

Yea, too complex.

Some comments in general...


The alternator/voltage regulator is not going to do a multi-stage charge unless you use a multi-stage voltage regulator(*), such as from Sterling Power Products:

http://sterling-power-usa.com/advancedregulators.aspx

That unit can apparently be piggy-backed on to the factory voltage regulator - but if the factory regulator is internal to the alternator, may require an alternator shop to mod the alternator to add external connectors.

(*) But that's okay - unless you are actually draining your starting battery a significant amount on a regular basis (you really shouldn't do that), then you DON'T need a multi-stage charger for it anyway. If all you are using it for is starting, then the factory alternator/voltage regulator will maintain it just fine.





For simplicity and reliability, what I'd do is:

This for charging while driving:

http://www.expeditionportal.com/foru...y-setup-for-50

I personally run a dumb solenoid split-charge relay setup in my own truck.

If you really must have multi-stage charging for the aux batteries while driving - and I can't object to that, it is after all a good thing (though not needed for the starting battery), then run a couple of multi-stage DC-DC chargers. There is an off-topic mini discussion of those here (post #203 - #208):

http://www.expeditionportal.com/foru...roblems/page21



This for charging from the solar:

http://www.solar-electric.com/modubachco25.html

Use it for the two aux batteries. You don't really need solar for the starting battery unless you are doing something silly like actually draining it rather than just using it for starting.

The Duo should be plenty large enough at 25a, even with the second panel added. If for some reason it turns out that it's not big enough to handle the second PV module - then run one Duo for the 215w permanent panel, and a second Duo for the portable panel.


This for charging from shore power:

http://www.chargingchargers.com/chargers/12volt/sec1230.html

It can do up to 3 batteries at the same time, though only 30a shared between them. That's okay, the smaller batteries will reach full charge voltage pretty quickly, and then most all of the output current will be going to whichever battery is still low.

The only caveat, is that with the Samlex, if you charge two (or three) batteries at the same time, then you have to switch it into 2-stage mode instead of 3-stage mode. So it will bulk and then drop to float and omit the absorb stage.

Fine, no big deal - the solar can take care of the absorb when the sun comes out if you aren't driving, and the alternator can take care of it if you are.

The reason to use 2-stage, is that when charging two different batteries (i.e., not tied permanently into a full-time bank), one will be full before the other, and so by the time the lower battery is fully absorbed, the higher battery ends up overcharged. So you set the charger to 2-stage and then it runs the bulk stage until all three batteries reach 14.4v and then drops to float.



I've said it before, and I'll say it again "AGM Specific" is marketing BS. Almost all AGM batteries take the same charge routines and voltages as almost all FLA (flooded lead-acid). If you look at the manual for the SunSaver duo charge controller I just linked, and also look at the manual for the Samlex charger I just linked they both have switches to set them. The switch positions are:

AGM/FLA
or
GEL

What works for AGMs works for FLAs and vice versa. The only caveat to that, is that with an FLA, you can push it to a higher voltage (as recommended by HandyBob, and I concur with him on that), but you'll use a bit more water. You shouldn't do that with (most) AGMs - they might pop their seals.

But only a programmable charger, or one pre-programmed for that (such as an Iota with IQ/4 module) will push a battery that high anyway. The SunSaver Duo and the Samlex will both bulk the batteries up to 14.4v which is what is recommended for 99% of the AGM and FLA batteries on the market. (Though, the Duo is in fact programmable though the use of Morningstar's interface and software so you could use it to pump the battery higher if you wanted/needed to.)


And also, batteries of different make/model/type/age/religious faith/etc WILL play nice together if they are only tied DURING CHARGING. It is only when tied into a full-time bank (series or parallel) that they must be identical.

Well, any mix of AGMs and FLAs will play nice. GELs require special handling (lower bulk voltage) and should never be mixed with anything except other GELs.

Of course, that's true only as long as you are using either a constant voltage charging system (like an alternator/voltage regulator), or a 2-stage charger. 3-stage is only for single batteries, or multiple batteries tied into a permanent bank.




Okay, so that's my recommendation. But perhaps you've already decided how you're going to do it, and are just looking for someone to check over the schematic for gotchas.

That's okay. Lemme see...well...gee...it looks complicated. Kinda scary. So...um...what's this job pay anyway? Is there hazard pay?

Just kidding.


Don't worry about getting more amps. Optima recommends 10a anyway, and their Optima branded charger only does 12. Some AGMs can handle ungodly amounts of charge current - such as Odysseys which are rated to handle an unreal (and likely impossible to achieve in the real world) C*4 charge rate - but most specify C/4 or less.


You can go crazy trying to engineer the most perfect system - but at the end of the day, you're still just dealing with a hundred pounds of lead, water and sulfuric acid. I.e., batteries are all limited lifetime junk. Focus on simplicity and reliability and build a system that is "good enough to get the job done".

[BigJimCruising]

For some reason (probably me) I can't get the diagram to enlarge enough to give you a lot of details but I will offer a few observations based on my travels.

1. Ditch the solar entirely. In real life and given a choice most people will not camp in the sun! Use the savings for batteries. No matter what else you do it all still comes down to batteries and amps. Fit the biggest batteries you can squeeze in there and make all the batteries in each system identical. Also use the types of batteries that will be the easiest to locate in the more remote areas you will travel. Nothing worse then using high cost batteries only to have one fail and need to wait days, weeks or longer to get it replaced. I'd stick to common types of auto batteries since these are easy to find anywhere and you won't need to deal with multiple types of chargers. (you can run everything off the alternator and an inexpensive battery charger).

2. From what I can make out your system is very complicated. You need to make this as simple as possible with the least amount of parts possible. In the field not everyone will be able to trouble shoot or repair a system with so many parts and wires. Remember the KISS principle and the people who will be using your vehicles.

3. Before getting to much into this system you might want to find out what types of connectors and voltage's will be required by the different crews, they might not all be the same. And you can never have to many outlets!

4. Again, remember KISS!

Good luck! Jim.

[Kiomon]

Thanks guys for all of the help. It's definitely a complex system, the main items that I seem to be adding the complexity is my desire for monitoring. Let me think about eliminating some stuff. Luckily Most of the add ons can fail and the system still run. The big item is the inverter and that's driven by the type of battery charging we need for the camera batteries.

@BigJimCruising Good idea on potentially using more readily available batteries and wiring them to make a bank. Let me check the layout and see if I can fit them all and the weight impact. Also you can try this link to see if the diagram larger. http://fmfac.files.wordpress.com/201...al-system1.jpg

@dwh thanks for those links. I like those simplified diagrams and also those dc to dc chargers, was looking for something exactly like that.

Keep the thoughts coming.

[BigJimCruising]

Ok I got a little bit better look at your diagram and must admit to a bit of jaw dropping awe. That's quite a system which seems designed by and for an engineer! Since I don't think that you'll have to many engineers operating your VW I think you'd better break this down even further. Here's more ramblings from a simple guy.

1. I'd sure stick to a starter battery and as many similar coach batteries as possible. One big cable from whatever type of isolator you choose going back to the coach batteries.

2. Ditch the combo charger/inverter. Check out some of the chargers made for RV's. Should be no problem finding one around 65 to 95 amps.

3. Try to get a number of how many watts all this gear will require and get a separate Inverter to handle that load. You might be able to use a "dirty" inverter like the kind you find at some Walmarts and some auto parts stores. Will depend on your future users equipment. (I don't know jack about film equipment) Anyway my reasoning here is much like my previous post. It's easier to replace individual parts then using a harder to find multiple component unit.

4. Still ditch the solar. To few watts for only a few hours a day. Plus the whole camping in the sun thing.

Question: how often will your users being moving locations?