Batteries Discussion

[Zach Woods]

The following is archival.

*****

Re: Battery Questions


Hello -

I think I can answer most of your questions - see answers below
after your questions. If I am not confident of my answer I have
marked that in my answer.

I am basing my answers on both experience with my Westfalia and my
understanding of the Westfalia electrical system.

Zach Woods
zwoods@...

--- In sprinter_westfalia@yahoogroups.com:
>
> Hi All,
>
> I'm planning a one-week dry camping (no electric hook-up)
experience
> in the boonies this spring with the Westfalia and want to make
sure
> I understand the battery situation so I don't get stranded. Here's
> my thoughts...are any of these incorrect?
>
> 1) The Westy has 3 batteries total - 1 vehicle battery and 2 coach
> batteries - and all are somehow interconected.

Yes.

> 2) The vehicle alternator, if the Sprinter is running, will charge
> the vehicle battery AND the coach batteries?

Yes.

> 3) The excessive use of the coach batteries will NOT run down the
> vehicle battery...i.e. I will still be able to start the vehicle?

Yes. But keep in mind that some electrical drains are likely
running off the vehicle/ starter battery. I am not 100% certain but
I am pretty confident that the vehicle stereo, the engine pre-heater
(dashboard switch - exhaust located in the right front wheelwell),
and the cigarette lighter outlet in the dashboard will all drain the
vehicle/ starter battery.

> 3)The generator will charge the coach batteries AND the vehicle
> battery?

I am not 100% certain on this but I am reasonably confident that the
generator will charge the coach/ camper AND the vehicle/ starter
batteries. I know that when you plug in to shore power you are
charging both the coach/ camper AND the vehicle/ starter batteries
so it stands to reason that the generator would also be charging all
of the batteries.

> 4)What battery powers the generator starter..vehicle or coach?

I do not know but I would assume the coach/ camper batteries.

> 5)An electric hook-up will charge all 3 batteries (I am pretty
> certain this is correct)?

Yes.

> I just want to make sure that even if I do something stupid (short
> of leaving the vehicle lights on), I will still be able to start
the
> vehicle and/or the generator to recharge.
>
> Does this all sound correct?

See above.

> Thanks for the advice!!

[Zach Woods]

Re: Battery Questions


Agree with the answers below. Probably figure on starting up
something every 3-4 days or so (generator or engine).

1. Watch your battery gauge (10 bar gauge on central console) and
voltage reading on central console. Some folks suggest that for best
battery life, you don't use batteries below about 12.4 volts (which
looks like 4-6 bars battery)--not very realistic in a Westfalia 2
battery system. Don't want to totally discharge the batteries as it
apparently shortens the lifespan of batteries (some things go off
automatically when the coach batteries drop down to 10.something
voltage--the heater and fridge, if I recall correctly).

2. As between the generator (which sends 120 volt electricity to the
120 volt battery charger) and the 200 amp engine alternator, it seems
that the alternator seems to charge the engine and coach batteries
faster.

3. When it gets to about 4 bars, you may want to crank up the
generator and let it run for awhile. The generator uses the coach
batteries to start-up (so the coach batteries need sufficient charge
to do that). Before heading off on your trip, crank up the generator
and let it run awhile. The more time between uses of the generator,
the longer it'll take for it to start-up (could be the need to fill
the propane lines???).

You'll have to run the generator for awhile (2 hours) to get back up
to 10 bars (although the batteries can really take much more charge
beyond the 10 bars, but you'd be running the generator for way too
long). (That's probably why I think the Westfalia manual may have
said something about plugging in once a month or so for 48 hrs to get
a really full charge???)

Alternatively, you could start up the engine and drive it a bit--
about 45 minutes. Keep in mind that if you're running anything else
(any A/C or other heavy drain), the alternator will be supplying
current to that and less able to charge batteries as fast???

4. Emergency--engine battery dead.

Options include

--cranking up the generator to recharge engine battery, or

--jump-starting from coach batteries (use lots of caution to avoid
shorting out stuff connected to coach batteries--maybe best to turn
off all 12 volt system using red lever next to sink, disconnect one
coach battery cables, and then use as standalone jumpstart battery--
don't know if alternator will still try to charge the coach batteries
when red lever is off).

5. Emergency--coach batteries dead.

Just crank up the engine.

6. Emergency--coach and engine batteries dead.

Out of luck. Call Auto Club.

In the future, maybe buy a jumpstart kit with built-in sealed battery
(from Costco or elsewhere; Consumer Reports rated these awhile ago).
These can be recharged from 12 volt or 120 volt.

Or, a solar panel (the 5 watt dinky ones probably aren't enough to
recharge a battery; just enough to maintain).

[Zach Woods]

Re: Circuit breaker / gel batteries


Howdy -

I have hooked my Westy up to 110 without testing the GFCI circuit
breaker and everything worked fine.

I am assuming that what is listed in the Motorhome Supplement
concerning the above is there first and foremost to cover all the
legal bases for Daimler/Chrysler/Airstream/etc.

It can't do more than slow you down to perform this GFCI test when
connecting to 110 and it could turn up evidence of a problem with
the GFCI circuit breaker before it was uncovered the hard way - by a
person being injured due to electrical shock. The GFCI circuit
breaker is intended to turn off the 110 if the circuit grounds
improperly/ suddently and thereby increase safety.

I do not know of a specific way to test how "healthy" the gel
batteries are. I am going to try to maintain mine as best as I can
(follow the recommendations in the Motorhome Supplement) and figure
that I will notice when they appear to be functioning below what I
have come to expect.

Zach Woods
zwoods@...

--- In sprinter_westfalia@yahoogroups.com:
>
> Happy 2006!
>
> What's the rationale for resetting the circuit breaker everytime
you hook up to the 110 network? Is it necessary everytime?
>
> Is there a test to determine how "healthy" the gel batteries are?
>
> Thanking you in advance........

[Zach Woods]

Re: Circuit breaker / gel batteries


The GFCI breaker--like the little ones in the bathroom and kitchen,
you're supposed to test every once in awhile (monthly???)--so maybe
the powers to be figure that by putting the instruction in--you'll
effectively have tested the breaker everytime you hook-up (and maybe
breakers need to be switched on/off to keep them working properly???
and not get stuck???).

There was a long thread in RV.net awhile back re hooking up to the 30
amp/50 amp sites. Folks argued that one should turn off the 30 amp
circuit breaker in the campground box before plugging in your power
cord, then after plugging in cord, flip the box circuit breaker back
on (and similarly, turn off that circuit breaker before
disconnecting). Maybe that's the same thought re vehicle GFCI on/off
when hooking up. Also, lots of discussion re whether that was
good/bad for the circuit breaker as to whether it was designed to be
an on/off switch.

Get 10 bars after fully charging (try charging for 48 hours straight
on 120 volt electrical outlet). Maybe lower bars after fully
charging is an indication of how "healthy."

[Zach Woods]

Re: [sprinter_westfalia] Re: Circuit breaker / gel batteries


A good source of info on gell-cell batteries (and auto and RV batteries in general) is the battery FAQ site: http://www.batteryfaq.org


The gell-cell specific info (with links to more) is here: http://www.uuhome.de/william.darden//carfaq7.htm#gel


I've never really paid that much attention to the battery gauge other than make sure it has more bars on than off. Even after a night of running the heater, fridge, and inverter I don't think I've ever seen it below 5 or 6 bars. When storing it I do make sure the battery is off since the propane detector is on whenever the battery is connected (was in my case -- my propane detector failed and I haven't bothered to replace it).


As for the hooking to shore power -- I've never noticed any problem. I guess I should check and make sure the breaker does indeed work -- it's never been tripped. I've connected the van to 50-amp, 30-amp, and 20-amp outlets and never had any problem (I had a 50-amp outlet installed at our old house in New Hampshire for a previous bigger RV; use 30-amp service at most campgrounds; and our new house here in Oregon only has a 20-amp outlet outside).