Aux battery for beginners

[randalieren]

Hi folks. I want to install an aux battery and solar kit in my new-to-me '84 Vanagon. I was hoping to buy the kit from GW, but they are sold out and the more I read, the more I realize it might not be the best build. So it's looking like it's going to be a project for the autumn.

I'm pretty handy and I worked for a while on a (residential) solar installation crew, so I have some basic knowledge. But I'm not an electrician or an engineer and I'm a little bit overwhelmed by all of the options and schematics.

Is there a step-by-step resource out there for putting together a system from scratch?

Much thanks.

[valvecovergasket]

blue sea has good diagrams that accompany their equipment

but you need a combiner of some sort and a second battery. id keep the chemistry the same as it makes things easier.

then a dedicated fusebox for your house battery loads is a good idea.

thats pretty much it for the most basic system.


have a look here
https://www.bluesea.com/support/articles/58/Battery_Isolators_and_Automatic_Charging_Relays

i did a similar system to whats shown above. common ground bar for the house stuff, going back to the house batt with one large lead.

a blue sea fuse box for the house stuff, as well as moving the factory westy loads to that fusebox, a bluesea ACR to combine the house and primary whenever either the engine is running, or i have the charger (which is hooked to the house batt) plugged into wall power, via the plug on the side of the van.

adding a remote solar tap to this is as simple as adding another lead into the secondary batt's fusebox.
i swapped to the GW hookup panel in place of the original city water, and left a fuse for a future solar setup on ours. idea was to use a solar suitcase and plug into this.

it all becomes pretty modular once you have the battery, the ACR, and the secondary batt's fusebox.

a few pictures of the van install to give some idea

the battery, with ACR and the two fuses as shown in the diagram, mounted to a little panel to the side. i had a spare vdo gauge in the parts bin so wired that up to show batt voltage on a switch, its a little more precise than the 3 led westy battery indicator

the fusebox and ground bus bar up front under the sink

iota charger and its breaker

the house batt is a cheap-o $150 autozone special.
no complaints so far running a webasto, engel fridge, various charger outlets in the van, overhead kitchen led lighting, sink pump, etc for 2-3 day trips.
_________________
MegaSquirt resource - SpitfireEFI.com

gone, but not forgotten: '83 tdi westy - swap thread

[jmillsj]

When I did mine a few years ago, I started with AM Solar: https://amsolar.com/

They have expanded their offerings and now have kits for vans. They have wiring diagrams and their support is great. When I did this, all they sold were Victron batteries. I bought my batteries from Battleborn directly, and am very happy. AM Solar now sells Battleborn batteries.

Battleborn has a lot of form factors, many more than when I built. You may also want to check them out: https://battlebornbatteries.com/

My system has an onboard charger, inverter, solar charge converter and two 100 watt solar panels. My battery bank is 200 ah and that’s plenty for my needs. With solar panels, I never run out of juice, and could have gotten by with 100 ah most likely. In any case, I am very happy.

One thing I did was separate my system from the start battery. I think this simplified things and I don’t have to worry about drain on the starter battery. I don’t need the alternator to charge, since I have solar panels, and my onboard charger allows me to fill the batteries through my shore power connection. My only regret is the inverter. It rarely gets used and takes up lots of space.
_________________
1985 Vanagon Westfalia EJ25
Vanagon owner since 1995

[dabaron]

[Vanagon Nut]

To help us help you, what do you want in, from, the system? Will aux battery be SLA, Lithium, AGM ?

Based on hindsight, were it me, I'd design a simple system with location of parts - physical space, wire size capability, that allows for future upgrades, added loads. Start simple to get rolling, add as you find what your true needs are.

I didn't look too hard, so didn't see any obvious relevant links but there should be info here:

https://www.thesamba.com/vw/forum/viewtopic.php?t=525798

Good info can be buried in a thread or in a thread with a somewhat unrelated looking title. Use key word searches within a thread really helps, search gallery for images that make sense to you, search for posts from user name on image.

Neil.
_________________
1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[fishgo]

[valvecovergasket]

[randalieren]

Hi everyone, and thanks for your replies. I know there's a lot of info buried in old threads, so I apologize if I'm retreading on well-worn territory.

I want to run lights/radio, and to have 110v power available to charge phones and/or laptops. Ideally, I would like to be able to run the stock fridge if necessary, but I am also replacing my LPG tank, so i will have that option for when I'm not on shore power. Nothing too fancy or powerful needed -- I just want to eliminate any chance of killing my main battery at camp, and to have reliable 110 v available for casual domestic uses, preferably even when we are on the road.

[izzydog]

[quote="valvecovergasket"]

[dabaron]

[zoti]

I know ow to install things but not familiar enough with solar and correct wiring setup.

Here's what I would like to do and maybe someone can help.

As far as consumption I plan to run:

- 12V fridge
- Maxxair fan
- Charge cellphone , iPad etc. (no computers)
- Led lights
- 110v inverter (optional)

I was planing on a 100W panel and 100AH battery. My trips will be a few days long at most. I'm thinking of keeping the option of adding another 100AH battery and and optional extra 100W folding panel that I can set up next to the camper if I need the extra charge.

I would like the solar to be able to charge both the aux and main car battery and same with the alternator.

Is there a good schematic I can work of and a good list of parts I will need?

Would this kit e a good place to start? (I'm not looking to spend thousands on a setup).

https://www.amazon.com/ECO-WORTHY-Controller-Inver...amp;sr=1-7

[Vanagon Nut]

[izzydog]

Ok, this is good start.

You don't really need to charge the start battery with solar. If you are worried about your start battery being charged enough to start (in case there is a mystery drain on it) you can always jump your start battery with your aux battery. Done it a few times myself.

A 100AH lead acid battery is really only 50AH of usable battery if you only allow a 50% discharge to your aux battery. 50AH might be enough for a day or two depending on how much sun is shining on your panels. I have two 100W panels and a 100AH lithium battery. As long as I can get a good, long day of sun, I can run my fridge and lights for many days. Lithium batteries are expensive up front, but pay for themselves in the long run when you consider replacing lead acid batteries every 3 years or so and that's if you've taken care of them and not discharged them too deeply.

My panels are the thin, flexy type that I store in the upper bunk when traveling. I have a 50ft cord exiting the license plate door (via Anderson plugs) that allows me to put the panels in the sun and the van in the shade. Mounting them to the van means you have to park in the sun. Not a great idea out here in CA when temps get near 100F.

I still have an inverter in a box from 10 years ago that I've never used. Most everything I have runs off 12V these days so no need for the inverter.

My solar controller and battery monitor are made by Victron and, via bluetooth, allow me to monitor what's going on with AH left in the battery and watts coming in via the solar panels. These are good things to know in the middle of nowhere and you are not sure what's left in your system. Having a battery monitoring system is another plus for lithium batteries.

If I were you, I would buy components that could be used with a lithium battery and when you are ready to jump from lead acid to lithium, you'll already have what you need. This is the bluetooth solar controller I use: https://www.amazon.com/gp/product/B075NPQHQK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Hope that helps...

[SSWesty]

[zoti]

So how would you run a fridge for a longer period of time?

[SSWesty]

For the stock fridge propane will get you about 2 weeks of runtime depending on the amount of cooking you do with the factory stove. To gut it out with solar and batteries it would seem like 400 watts of solar might keep up if you have sun. Stock fridge on DC with the engine off is the wrong tool for the job.

[zoti]

[dabaron]

[metropoj]

Beginner here raising his hand too !

I also spent a lot of time perusing through SO many threads

I hope this isn't seen as a hijack ( not intended ) but thought maybe my questions may help the OP as well ?

I got a TF49 new so cheap that I couldn't say no. NOW the real money is in the system to run it !

I took lots of info from several threads and decided to try a diagram with a Flooded Group 31 under rear bench, a Shore Charger > 6 AMP, a White Rogers Relay 120-902 Isolator, some fuses here and there and wire the fridge direct to the house battery for now ( will consider the fuse panel later on ). Will use wire feed from the old Westy Relay under drivers seat or wire into fuse panel for ignition on trigger for White Rogers 120-902 Isolator

I see many run an additional wire from the Isolator to the Start battery. Why is that ?

If I don't want to combine the 2 batteries to the Isolator. Is that ok ?

I thought my 120A Alt will charge both system separately and without the need to "combine them" so that is what I don't get. Did I get that wrong ?

I used Visio and some incorrect drawing shapes to represent different things ... can't be any worse than an outboard motor shape, lol !

Comments and hope it helps out the OP too.

_________________
John.
86 TiiCo powered Westy.

[crazyvwvanman]

There is an issue with or two your diagram.
The control wire to the 120-902 should NOT be from 'ignition on'.
It should be from a source that is 'off' during starting but on when key on or engine running.
This is easy to do.
The fuse could be 5 amp.
Also, the 120-902 needs a small gauge ground wire, not shown.

The starter motor stud is nearly directly connected to the starting battery so using it instead of the battery is fine, even preferred in this case.

Mark