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crazyvwvanman Samba Member
Joined: January 28, 2008 Posts: 9895 Location: Orbiting San Diego
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Posted: Tue Oct 21, 2014 1:19 pm Post subject: |
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This seems like a good time to remind people to keep in mind that fuses in general are not exactly precision devices. For example the 100 amp fuse will not blow just because 110 amps flows through it. In fact the manufacturer says it would let 110 amps pass through for 4 hours or more before it blows and might not blow. It would even let 150 amps flow through at least 1.5 minutes and possibly for as long as 1 hour before it blows. It could let 200 amps flow for almost 2 minutes. The point I am making is that there is slack built into the fuses so don't make the fuse so large that it won't blow when you really need it to.
Here is a link to the specs showing the above.
http://www.mouser.com/ds/2/240/498-56949.pdf
Mark
thatvwbusguy wrote: |
I have been using LittleFuse MIDI/AMI fuses for a while on most projects that require 10AWG or larger wiring. They are tough, don't require the need for a mounting bracket and can be found in 30A-200A ratings...... |
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pushkick Samba Member
Joined: August 09, 2007 Posts: 1366
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Posted: Tue Oct 21, 2014 1:53 pm Post subject: |
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all automotive 12 vdc circuit have a fuse box for this specific reason. i really dont know what you are talking about. and about fuses they are designed differently for different applications. some are exact amount of current and instantaneous blow fusses that are sometimes used to protect devices ( like scr's)and some are heat over time fuses. they are usually designed for a particular application. if fuses are not used they consider the current and size the wire accordingly to handle full load current. _________________ i see said the blind man to his deaf dog
i am going to quit smoking and drinking and die a healthy man. gotta laugh
there is no deed to the planet earth
1990 vw automatic camper
Last edited by pushkick on Wed Oct 22, 2014 2:47 pm; edited 1 time in total |
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djkeev Samba Moderator
Joined: September 30, 2007 Posts: 32433 Location: Reading Pennsylvania
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thatvwbusguy Samba Member
Joined: April 18, 2007 Posts: 1712 Location: Newmarket, New Hampshire
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Posted: Tue Oct 21, 2014 2:42 pm Post subject: |
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With two 225Ah 6VDC batteries wired in series, you will have 225Ah @ 12VDC.
I have never seen an automotive fuse of any type that will blow at exactly the rated amperage, nor have I ever encountered a manufacturer's data sheet that claims that they will. If Mark posts something here, you can be sure that he knows what he is talking about.
Many people choose circuit protection (fuse/breaker) based on the maximum ampacity of the wire it is protecting. It is much better to choose the fuse/breaker based on the full load current of the circuit. This will allow the fuse to do its job long before the wire reaches it maximum current capacity.
As a real world example, say we are using fifteen feet of 12AWG wire to run from an auxiliary battery bank to power the stereo, interior lights and 12V socket. Based on readily available ampacity charts, we know that a 12AWG wire of this length can safely carry about 30A, but if the full load current of the circuit is only 15A, it would be much safer to choose a 15A or 20A fuse to protect the circuit. Fuses are much cheaper and easy to replace than crispy wiring or a burnt van if something goes wrong. _________________ Jay Brown
'85 Zetec Westfalia
Newmarket, NH
If you want others to be happy, practice compassion.
If you want to be happy, practice compassion. |
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PDXWesty Samba Member
Joined: April 11, 2006 Posts: 6235 Location: Portland OR
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Posted: Tue Oct 21, 2014 3:20 pm Post subject: |
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djkeev wrote: |
Electricity gives me a headache!
I'll do fuses as recommended at each battery and for the ground.
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You absolutely do not need to fuse the ground wires. Just the positive leads. _________________ 89 Westy 2.1 Auto |
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crazyvwvanman Samba Member
Joined: January 28, 2008 Posts: 9895 Location: Orbiting San Diego
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Posted: Tue Oct 21, 2014 3:29 pm Post subject: |
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Our vans have lots of un-fused circuits in them. It varies by year and more fuses were added over time but they all have major circuits without any fusing. You can remove every fuse and still start the engine and drive away.
If you have have a source for precision fast blow fuses of sizes and types applicable to this discussion please share that source and the data sheet showing just how precise and fast they are.
Mark
pushkick wrote: |
all automotive 12 vdc circuit have a fuse box for this specific reason. i really dont know what you are talking about. and about fuses they are designed differently for different applications. some are exact anount and instantaneous blow fusses and some are heat over time fuses. they are usually designed for a particular application. |
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crazyvwvanman Samba Member
Joined: January 28, 2008 Posts: 9895 Location: Orbiting San Diego
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Posted: Tue Oct 21, 2014 3:56 pm Post subject: |
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I think the only ground fuse in question is the one recommended by the manufacturer for the BlueSea 7610 internal logic module. Grounds don't commonly have fuses but they didn't provide them for the dual power inputs to the module and instead they expect the user to install one in the small gauge ground wire.
Mark
PDXWesty wrote: |
djkeev wrote: |
Electricity gives me a headache!
I'll do fuses as recommended at each battery and for the ground.
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You absolutely do not need to fuse the ground wires. Just the positive leads. |
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Howesight Samba Member
Joined: July 02, 2008 Posts: 3262 Location: Vancouver, B.C.
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Posted: Tue Oct 21, 2014 4:35 pm Post subject: |
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djkeev wrote: |
Electricity gives me a headache!
I'll do fuses as recommended at each battery and for the ground.
Ok, stupid question time again.......
2 batteries,
I understand two 6 volt batteries wired to produce 12 volts is a superior setup for amp delivery and long life. 6 volt Golf Cart batteries are made more stout and tolerate repetetive deep discharge well.
So, I get two 6 volt batteries, each one rated at 225 amps
When wired for 12 volts do I have 225 amps available or 450 amps available?
Or does the additional voltage push the amps out faster thus I don't even have 225 amps?
Just color me electrically challenged..........
Dave |
Hey Dave:
Many years ago it was true that very few 12V "deep cycle" batteries were any good. Back then, only 6V batteries were built with industrial strength internals. Now, however, you can have your cake and eat it too. There are a number of excellent quality 12V deep cycle batteries on the market. The benchmark, I think, is still Trojan, and their prices are still quite good.
The trouble with the multi-battery setup is that the weaker one can create a vampire draw on the stronger one. This assumes that either through manufacturing tolerances or damage to one battery, one battery becomes weaker. If you maintain your batteries well and buy quality in the first place, multi-battery setups can avoid these problems.
But the question remains: Why have two if one will do? _________________ '86 Syncro Westy SVX |
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ThankYouJerry Samba Member
Joined: September 01, 2012 Posts: 2271 Location: Shakedown Street
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Posted: Tue Oct 21, 2014 7:54 pm Post subject: |
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Howesight wrote: |
But the question remains: Why have two if one will do? |
One will do... but only for so long (not very).
Aren't you effectively doubling the Amp Hours using two 12V batteries in tandem vs. using two 6V batteries in tandem?
FWIW... my two aux batteries (DieHard Platinum AGMs independent of a solo Oddesey 1200 starting battery) will run my ARB Fridge, LED interior lights, and a bit of music for about 2-3 days without needing to be recharged with: alternator (driving), 120v shore power, or solar.
BTW... Why on Earth would anyone need 100A or 200A fuses in a Westy?!?! _________________ 1990 Multivan - "Ohana"
1.8T, Auto w/3.27 R&P + Peloquin TBD |
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djkeev Samba Moderator
Joined: September 30, 2007 Posts: 32433 Location: Reading Pennsylvania
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Posted: Wed Oct 22, 2014 3:58 am Post subject: |
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Thanks for the info!
I feel smarter already today.
While I am admittedly a tad battery challenged, I do have some first person experiences that make me lean towards the basic flooded 6v Go,f Cart Batteries.
I've got two 72 volt GEM Cars (2 POS's) and one 35 year old 36volt three wheeled EZ Go.
The GEM cars run 12v batteries and while I remove them for the winter and keep them charged they are an expensive never ending PITA!
I've had Trojan AGM's, Trojan Flooded, and more recently Eastern Battery Flooded.
I've literally spent $1000's of dollars on batteries over a ten year period!
My classic EZ Go? It runs six 6volt Deka GC15's, the same ones I bought years ago, just finishing up Summer six and about to enter storage for Summer seven!
I keep the terminals clean, water them on occasion, charge them and GO! It's EZ!
Maybe it's the over electronic nature of the GEMs but I'm ready to toss them in a ditch!
I spent hours reading about suggested RV Batteries and the overwheming consensous is 6v GC batteries!
Their plates are thicker and more robust, able to handle severe deep discharges and recover, etc.
I also,look at the amp ratings, it seems easier to get 200 + amps out of two 6volt units.
Imhave some 24 volt electric amusement ride units (small electric cars and electric boats) whose batteries have held up for a decade now without any pampering at all!
I Should open up one of the cases and see what battery is in there and the ratings of it.
I know they have two GEL 12volts strapped together.
So confusing! Worse than buying tires!
Dave _________________ Stop Dead Photo Links how to post photos
Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473
Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537
Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert |
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djkeev Samba Moderator
Joined: September 30, 2007 Posts: 32433 Location: Reading Pennsylvania
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djkeev Samba Moderator
Joined: September 30, 2007 Posts: 32433 Location: Reading Pennsylvania
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kamzcab86 Samba Moderator
Joined: July 26, 2008 Posts: 7893 Location: Arizona
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Posted: Wed Oct 22, 2014 12:59 pm Post subject: |
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djkeev wrote: |
figure 50% is useable (from what I read) |
Interesting. I read 80% is usable, which would translate to 184 amps.
djkeev wrote: |
Neither my electric Boat or Car batteries will do me much good!
Both are lacking in Amps! |
Yeah, well, the Odyssey 925 (I thought it was a 1200) currently in my van is 28AH. The big test for the ARB is this weekend. Will see how those 28AH hold up. _________________ ~Kamz
1986 Cabriolet: www.Cabby-Info.com
1990 Vanagon Westfalia: Old Blue's Blog
2016 Golf GTI S
"Real knowledge is to know the extent of one's ignorance." - 孔子 |
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djkeev Samba Moderator
Joined: September 30, 2007 Posts: 32433 Location: Reading Pennsylvania
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djkeev Samba Moderator
Joined: September 30, 2007 Posts: 32433 Location: Reading Pennsylvania
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Posted: Fri Oct 24, 2014 2:52 pm Post subject: |
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I talked to my parts guy the Deka GC15 is about $150,
The Deka GC 25 is almost $250!!!!
The rating difference is small......the price difference is HUGE!!
It has four more pounds of weight in it, I'm not sure it that makes it $100 better?
Dave
Edit: I just came across a brand new, but about a year or so old, but no longer needed.
It is a Car Quest (Made by Deka aka Eastern Battery), Farm / Commercial, Extra Heavy Duty, 12 volt, 31HDP30, CA@32* 1260, CCA@0* 1125.
I'm thinking that if this accepts a charge it is much cheaper than two new Golf Cart Batteries.
It has a very high cranking amp rating but how does that figure into a 20hour amp figure?
If it does at all.
I know it isn't a deep cycle battery but my needs are not severe. If I monitor it and don't let it drain below 70% or so, I'll hopefully get a few years out of it?
My electrical needs are few, been keeping track of my Truck Fridge running on a simple car Battery......
http://www.thesamba.com/vw/forum/viewtopic.php?p=7417236#7417236
One thing fir sure..... If weight = performance....... This Sucker is HEAVY! I'd guess pushing up to around 65-70 lbs.
HECK!
It's free! When I brought it home it still had 12.2 volts and the factory plastic terminal covers in place. I have it on a slow charge right now, I'll see if it builds back up to 12.6 or so.
I will then load test it and see how it holds up.
(It even comes with a dead Stink Bug! The BEST kind of Stink Bug!)
One intriquing thing to me about this battery is that it is set up for a remote gas vent hose........
Dave _________________ Stop Dead Photo Links how to post photos
Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473
Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537
Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert |
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djkeev Samba Moderator
Joined: September 30, 2007 Posts: 32433 Location: Reading Pennsylvania
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djkeev Samba Moderator
Joined: September 30, 2007 Posts: 32433 Location: Reading Pennsylvania
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singler3360 Samba Member
Joined: February 25, 2009 Posts: 1191 Location: Corvallis, Oregon
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Posted: Sat Oct 25, 2014 10:36 am Post subject: |
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djkeev wrote: |
I'm quite confident the 1125CCA unit will perform well if I don't drain it too much too often.
Dave |
Sounds like you are realistic about using this battery compared to your original idea of the two 6 volt deep cycles. Nice score.
Did you ever find out how to determine it's Amp hour capacity? |
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djkeev Samba Moderator
Joined: September 30, 2007 Posts: 32433 Location: Reading Pennsylvania
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crazyvwvanman Samba Member
Joined: January 28, 2008 Posts: 9895 Location: Orbiting San Diego
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Posted: Sat Oct 25, 2014 11:36 am Post subject: |
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After sniffing around a little, it seems that battery might be in the 110 ah to 120 ah range.
Mark |
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