TheSamba.com :: View topic

Mon Jan 03, 2005 6:40 pm

mightyart wrote: I agree don't need to start no Fights this is a matter of personal preferance. Most people say the Optima batteries are the best (Sears about 150-190.00). for extra batteries. I got a new diehard for my starting battery, and am going to use the old battery to get everything up and going. Them I may buy an Optima, I'm still not sure.

An Optima battery was on sale in December at AutoBarn in NY . It was $130 for the yellow one (deep cycle) best one they had. You can leave it sit for long time, and still revive it without crusty deposits on contacts or having it die from leaving it sitting. You can mount it on its side if you want, too.

If you try to buy the 75 amp alternator instead of the 55, it is double the $$$ and you will not be able to find the boot that goes on the back to air-cool it. Not sure how a 55 amp alternator will do charging the 2 batteries. Best bet might be to recharge it in your garage with a regular battery charger after your trip.

and now you know why I haven't done this yet...

Mon Jan 03, 2005 7:12 pm

Hey here's what I did with a 73 Westy I built. It started out as a Kombi but ended up a Westy. :wink: I took it all over the place. Did an 8k miles+ tour of the US in it in 96 with zero problems. :wink:

At the time, I could NOT find a battery isolator that would work with the Bosch internally regulated alternator. It just was not available. So I went to my local electronics salvage warehouse and found me a big ol switch... read on. :roll:

I installed a good quality Interstate battery in the drivers side engine compartment. Nearby on the gastank cover, I mounted a 60 amp rated gang switch. You know, one of those Frankenstein switches with the big contacts! It was about the size of two cigarette packs. When the switch was on, both batteries were coupled to the charging system in paralell. When I parked for camping, I'd flip the switch open and the battery would be 100% physically isolated.

I connected ALL of the camper electrics to the auxillary battery as well as the 300 watt stereo. The reason the stereo went on the aux batt circut, besides the obvious reason of listening to the tunes when camping, was so that the battery had a draw when driving down the highway and it would therefore accept a charge. Batteries are funny like that...

Total price?? Less than $100 for everything. The aux battery lasted about three years. Not bad considering I would pretty much take down to near nothing on a three day campout... and I did a lot of camping in that Bus. I miss it. Sold it to a hippe painter dude for $2500 cash.

Anyway, it was easy. Get to the campsite, flip the switch and camp out! Two mornings later, start the bus on the good battery, flip the switch and let the aux charge up! If I flipped the switch before starting, the load of the weaker battery would bring the voltage down and it would crank slow...

so there's another alternative and it's cheap and reliable...

Mon Jan 03, 2005 9:25 pm

I currently use the 55A alt. to charge both batts. Was able to get a complete wiring harness at slavage (ended up re-wiring anyway), had to get a new Bosch relay for it to work.

For the charging, not sure how well it works while driving, though the onboard charger device helps when connected to land line! I plan to add one of those Optima Yellow batts soon, but they are quite pricey.

http://www.optimabatteries.com/publish/optima/amer...specs.html

Mon Jan 03, 2005 9:44 pm

Hell, keep it simple, and do it like Westfalia did. Buy a relay at your FLAPs for $5 and a battery. Wire the relay so that it closes (connects the two batteries) when the alternator starts charging. Get power for the relay by splicing to the blue wire from the voltage regulator. It will only connect the two batteries when you are charging, so you cannot accidentally drain the main battery.

The second battery automatically charges whenever the engine is running, you can run it dead and still start from the other battery, everything without having to remember to use any switches or swap batteries, etc, etc.

Apply the KISS threory whenever you can. Overcomplicating things just gets you in trouble. ;-)

Tue Jan 04, 2005 5:50 pm

Don't even get me started on this topic. :twisted: Optima's are great but expensive, true deep cycle batteries are great too. A bigger problem is keeping the battery charged, how you separate them, the load they take and alot of other things.

Please do a search on this, I know for a fact Ive dumped more knowledge on this exact topic than I care to repeat. I will try to do a search myself and post some of those links.

So I did the search, here are the links. Its funny but the first three I ran across I also wrote to do a SEARCH on the topic. Not to be mean, but if you can read up on it first you can ask a more detailed question or not have to ask at all.

My System:
http://www.thesamba.com/vw/forum/viewtopic.php?t=65215&highlight=
Fridge Setup:
http://www.thesamba.com/vw/forum/viewtopic.php?t=64766&highlight=
Optima Question:
http://www.thesamba.com/vw/forum/viewtopic.php?t=61728&highlight=
Another Optima one and setup answer:
http://www.thesamba.com/vw/forum/viewtopic.php?t=62965&highlight=
General Isolator and Battery:
http://www.thesamba.com/vw/forum/viewtopic.php?t=60201&highlight=

Tue Jan 04, 2005 6:24 pm

ut oh he got started on the topic!!!

Tue Jan 04, 2005 7:24 pm

:wink: Yes, yes I did.

Wed Jan 05, 2005 1:00 am

Okay... Let's pretend this is a FORUM for talking to PEOPLE about BAYWINDOW related topics. You know, it's a place online for asking questions and getting advice. That's the point of a forum. Correct me if I'm wrong.

If I didn't want to know other people's opinions, I wouldn't have asked. If all I did was want to read past discussions and the information of people who are offended by simple questions, I'd be limitting myself to a select group of people's ideas and ways of doing things. I've found that by asking for EVERYONE's opinions I can get better ideas and easier ways of doing things than reading one person's personal opinion.

And since when is it a crime to ask a question on the forum? If you don't want to read stupid questions, then don't. My question was meant to be generic so that I can get many opinions. If you have more knowledge than you care to share, don't share anything at all. I'll ask as many questions as I want and everyone else should, too. You keep searching and stop typing if it's such a big problem...

Anyways everyone else has been really helpful and I appreciate them taking the time to type a few sentences to give me some insight. I have to sort through all my options... ;)

PEACE, LOVE, UNITY, RESPECT...

- Chris

Wed Jan 05, 2005 1:42 am

I had an aux. battery in my Westy.
My aux. was connected with the original Westfalia relay. This is simple and works fine. Now I prefer the only one battery; Now, I think I have less "dead batteries at the wosrt time".
However:

I wonder about "battery matching". You know that charging voltage depends of battery technology.
In theory both batteries should match the voltage regulator for a balanced and full charge.

I wonder if the deep cycle marine battery is OK together with another mostly used car battery.

Note that we already are using regulators designed for old battery technology with new battery technologies asking for a little higher voltage.
Is this really working efficiently ?

Wed Jan 05, 2005 1:54 am

When using an isolator.
What are the voltage drops thru the isolator ?

I hope, an isolator is better than a two diodes set up....
Diode drop is 0.7 volt.
Where can I find an isolator schematic ?

Wed Jan 05, 2005 7:56 am

Simple battery Isolator schematic bottom of page:
http://www.hellroaring.com/rv.htm

Wed Jan 05, 2005 8:39 am

twinfalls wrote: When using an isolator.
What are the voltage drops thru the isolator ?

I hope, an isolator is better than a two diodes set up....
Diode drop is 0.7 volt.
Where can I find an isolator schematic ?

Most standard isolators are just that, two diodes which won't have much voltage drop (.7V sounds high but that still isn't enough of a voltage drop to worry). In schematics that little triangle with the line on one side is a diode, diodes are just one way gates, voltage goes one way but can't go the other.

You shouldn't have to spend more than $25 plus the battery for an isolator and even less for a relay. A relay just requires more wiring knowledge since you have to power it whereas an isolator is plug and play. Hook up the alternator to one post and a battery to each of the other two.
You also don't need an extra fuse block if you power your original fuse block off of the second battery leaving just the starting circuit hooked up to your original starter battery.

Optimas are great IMO but only worth the money if you have a large load, a winch, lots of lights, etc. Anything you have in a bus will work just great with a $60 standard deep cycle marine battery. Just remember the more amp/hours the longer it will last. You can actually calculate how long the battery will last if you know your load.

Wed Jan 05, 2005 9:37 am

Thanks to Mightyart's link to Hellroaring.
This is what I was looking for: Quote: The Hellroaring battery isolator / combiners BIC-75150A and BIC-75300A do not drop significant voltage like a typical diode isolator does.

Instead, they act more like just a few feet of large gauge wire when it is switched ON!

When full charge is approached, a diode isolator still drops from 0.55 to 0.7 Volts. This voltage drop reduces the voltage available to the battery which inhibits full and complete charging within typical operating times.

Now the Good News!

When using the Hellroaring BIC-75150A or BIC-75300A, the voltage drop is expected to be less than 0.005V at full charge (Our test vehicle measured about 0.001 Volt across a BIC-75150A. ) This difference is insignificant to the battery charge! To put this in perspective, there will usually be more voltage drop in the wires to and from the battery!

Indeed there are isolators of two kinds:
The dual diode setup.
The no drop isolator.

Wed Jan 05, 2005 10:23 am

I must have missed an argument (or at least a jab), but that's no surprise. :D

Chris, you asked for opinions which are hopefully based on either research or first-hand knowledge.

My opinions are based on mostly research and some experience with my set-up.

1. I lose about .7VDC through the isolator.
2. Deep cycle batteries are intended for LB use.
3. Deep cycle batteries "like" longer, "weaker" charging.
4. Use a seperate fuse panel on your LB with a big fuse or breaker mounted close to the battery.

I don't visit here that often anymore, and I won't engage in an argument.
What I've learned by reading lots and lots of information from people who know this stuff far better than I is that a starting battery will not hold up in a heavy cycle of repeated dishcharge/recharge. If you're running lights and other light stuff, this may not be a problem for you. Starting batteries can take the full force of the alternator, deep cycles don't handle it well. Use a lighter guage wire to feed the LB. The down-side of this is that you could spend 40 hours driving to recharge your deep cycle after heavy use.

Once again, my favorite saying in these matters: "The good thing about the internet is that there's all this information available. The down-side comes in trying to figure out what's valid."

Opinions are fine, real-world experience is better. That's why Colin's (Amskeptic's) posts are of value to me. He's approaching a half-million miles on his engine. I can still disagree with him on occasion, but you have to believe he knows what he's talking about.

I hope this helps somebody.

Wed Jan 05, 2005 10:28 am

Westy Racer,
Thanks for that advice, sounds good, cheap, and reliable -everything I could ask for. It sounds like what i would do to keep it stock the best way, but I won't put any holes in my bus' body. I would mount a piece of wood somehow to existing holes, like adding a blocking near the volt regulator in those holes? Got photos? I like.

Adventure wagen,
I hear what you're saying, and I appreciate your info in the past threads, and don't want to fuel the fire, but I still have questions on the 70amp vs 55amp alternator with specific batteries and the charge rate, the availability of the boot used for cooling it, its consequential value and my necessity for it, and want to weigh all my options before I hack shit up...

I like to see pictures too. I am not into hack jobs. I would rather post a thousand times than hack shit up because I thought I knew. There can be more than just one answer, and in time someone who posted an answer previously MIGHT HAVE HAD A MELTDOWN since. Good thing I didn't go off the advice of that old thread.

One time I searched a thread on tires. The thread recommended Yokohama 356 ? tires. Great advice, but they don't make those anymore.

The knowlegeable guys here hate the new unknowing-naive-bumbling bus drivers for not knowing their shit. Its natural, and I can take it. I do what it takes for my bus to live forever, even if I have to act like a di.C-k.

There are lots of variables in this subject, and it might not be so cut and dry, especially when everyone has different needs, electronic demands, budget, hack-job avoidance factor,etc...

I use search function also, but why re-post the old thread? Is it OK to have to sort through 4 pages of old bullshit that you just said you already read and advised just to get to the one new post at the end ????????
Maybe I'll do an example.

If its clearly a search related issue, I'm with you. Flame away.

Wed Jan 05, 2005 10:59 am

One of the other things you might want to think about... how many amp hours do you need? You could go through the trouble to calculate it all... and figure out how long one battery is capable of going before needing a charge.

The problem? As the voltage of the battery drops it does so in a less than linear way! You've got a small working range of voltage before your battery is no longer capable of powering the devices you want to use!

So... the boating solution is take two 6 volt deep cycles (HUGE... 60-70lbs a piece.) and tie them together to make 12 volt. The two batterys have more total amp hours than a single 12, the problem with these... is weight.

Why? If you can discharge a battery 80%, discharge one battery 80% vs discharging 2 batterys... 8)

Crash course:

1 amp over 1 hour is 1 amp hour. In 24 hours if you use an amp over the course of an hour you use 24 amp hours.

Heres a boating based guide: http://www.fourwinds-ii.com/12%20volt%20requirements.htm

Watts divided by volts = amps

Example: 60 watts divided by 12 volts = 5 amps

Your lights, stereo, tv... anything hooked up uses power. You lose voltage to heat over the wire as well... so you have to take that into account as well! The more power you push through, the higher the resistance goes! Oversized wires are your friend when it comes to getting the most time out of a battery bank.

Hella has some pretty slick interiour lights that are LED's... check west marine, but they run in the 20-25 a piece! Never change the bulb... and use next to no power though :D

Wed Jan 05, 2005 1:48 pm

Sorry to all if you thought I was too mean on the Search rant. I still posted some of the better old threads so I wasn't trying to be a biatch 8) Old threads aren't always the answer but they can definately give you good background to start a new thread.

Anyway, in regards to:
Quote: but I still have questions on the 70amp vs 55amp alternator with specific batteries and the charge rate

Charge rate will be dependent mostly on your charging system (alternator), and should determine your battery (flooded lead acid instead of Gell). Both batteries are good, only bad thing about gell is they require a precise charging which the alternator can't provide and they are more expensive. They also have on average a shorter lifespan which is compounded by poor charging from the alternator, but this is not to say there aren't other options for charging your batteries (Solar or generator with charge regulators).
So you say 75 or 55 Amp, if you can afford the 75 it can't really hurt to have a bigger charger, but my not be necesary depending on what you want to run. You can charge your battery with a huge jumbo 200Amp alternator but if your running a PS2, fridge, and 40"TV (Pimp my ride style :evil: ) one puny battery is not going to do it. So first question is what do you want to run and for how long. I think RocknRod got it up to speed about determining your load. RV'ers have a rule of thumb of about 70AH per day per person. This is however a bus and you don't need to run a microwave, so maybe figure the number of lights you have, most original old style Hella's take 3Amps!!! to run. Your stereo will suck alot more and a fridge (4+Amps) at say 6-10hrs running will use 25-50Amps/day.

So considering I haven't really answered your question I wanted to point out one other thing about the isolator and the whole .7VDC drop. I don't disagree that this happens on some units, the question is whether or not it makes a difference. Charging a battery correctly (with a regulator or some charging unit) happens in three stages: Bulk, Absorbtion, and Float. To fully charge your battery you need to meet each voltage requirement for each stage. An alternator is not smart enough to differentiate the charge of your battery and what it should exactly get but its easy to figure out where the limiting factor is. Bulk charge is in the range from 10.5 to 15V, doesn't really matter where it happens. As the battery gets charged and the current begins to drop off from internal resistance, the alternator needs to supply 14.2 to 15v to the battery. If 14.2 is not getting to the battery is won't charge to 100% plain and simple. So the question is, if your alternator is putting out 15V but you have a crappy .7 drop in your isolator you still should be getting 14.3V to your battery which is enough. the other thing to think about is the guage of the wire going from the alternator to the isolator to the battery. You can measure what the battery has for a charge and then measure what its getting at its terminal while charging. So you should be able to determine how nice of an isolator you need to get before you buy one. Again if you can get one with little or no voltage drop probably the better :) Final stage is float or trickle charge which is at around 12.8 to 13.2, this is going to vary depending on your battery but the alternator can't handle this so charging won't be as efficient as it could be. Not a real problem for Lead Acid deep cycles but more of a problem with Gell.

I have alot more info on charging, bigger batteries in parallel and AH ratings for stuff if you want it. Ask away. I have my head out of my ass today so Im not as disgruntled as I was yesterday. As long as the dialogue progresses and more information is shared another post on the same topic is fine with me.

Wed Jan 05, 2005 5:55 pm

In addition to what adventure talks about... you can use some passive techniques to save power as well.

One way is to limit your number of plugs, and reduce the length of the wiring. This causes you to be "Forced" into using fewer things at once.

The other thing, is to use a boom box in place of the in car stereo. This saves the hassle of wiring it in with switches/fusible links... because normally the stereo doesnt get a hot 12v at all times! Wire it so you have power to it at all times, you'll leave it on, and discharge the battery.

The other thing that "I" would do, is set up your auxillary battery bank so that it is seperate from the starting battery. Using the diodes as talked about earlier... But when your camped, have a sissor battery cut off on both your starting battery and your auxillary. When your leaving, open both of them... no discharge!

ALL cars have a slow drain in some part of their electrical system... most times its measured in miliamps, but over time... this is what discharges the battery. You can track them down, or you can use a battery cut off!

Almost the end... "I" would use a boom box in place of a stereo... they are real easy on batterys, and rather than powering a couple speakers a reciever... external CD player and whatever else, save the amp hours for lights!

Ok, well almost last... Your fridge is one area you can save some power... a thermometer is your key! You can set up an electric fridge on a timer. For a given outside temp, the time needed can be very low to keep the inside cold. The other saver is to know whats inside, where its located and what you want ahead of time. Open the door, get what ya want, close it! A fridge with a higher R factor keeps stuff cold longer than a lower R factor fridge. Ice helps keep stuff cold... some of the hard case coolers are getting into the "Days" where theres still ice floating around in the water ( :lol: )

Ok, LAST...

Solar panels are helpful. The problem, you need lots of them and many hours to see any real difference. Solid (not the flexible type) are the most efficient panels. Flexible is easiet to store and lightest... but not nearly as good at capturing light. BUT, they are expensive per WATT they produce! You've got to really think about doing solar... instead of just firing up the engine to charge up your batterys.

Hope this helps you figure out what you want to do...

8)

Wed Jan 05, 2005 6:06 pm

Good post Rocknrod, lots of good tips. Only thing I will add is the refigerator should not be a problem as most only use 12volt while driving.
mine gets swiched to propane when parked, also here is a good link for solar power for vw's:
http://www.rvsolar.com/vanagon.htm

Wed Jan 05, 2005 9:41 pm

Quote: Good post Rocknrod, lots of good tips. Only thing I will add is the refigerator should not be a problem as most only use 12volt while driving.
mine gets swiched to propane when parked, also here is a good link for solar power for vw's:
http://www.rvsolar.com/vanagon.htm

My fridge is only electric, but I have a solar panel that I got from the link you posted. Those guys are really good, I had a problem with the regulator and they fixed it and sent me a new one.

You are also correct about the solar panel being a serious option. If you get to the point that you determine you need larger batteries than a single aux. deep cycle battery then you run into the problem of charching them. I have two 6v batteries (240 usable AH's) in mine that could never be charged by my generator, so I looked into it and got the solar panel. Its an 80 Watt panel that provides 5Amps. Once you get large enough batteries you pretty much have only three choices to charge them, solar power, generator, or shore power.

Good advice on having fewer plugs and shorter wire. Kill switches are great too. Ive put one in for my fridge and for both sets of batteries. Ive found that most everything has a ghost draw, and if your goal is to be 100% dry camping then you definately need to conserve energy. After living in mine for about 7 months I really came to have an appreciation for the amount of power we consume.