How far can I go on a starter battery load?

[GoBigEmma]

Hi Sambaverse,

quick question... how far will a regular starter battery (500 cold cranking amps, 75 reserve) load will get us if the battery isn't being charged while driving?

I know this probably depends on a million different factors, I'm not looking for an exact number.

Situation is this: Alternator light is one whenever the car's on. Starter voltage shows 12.3V approx, so battery isn't charging. Alternator is spinning just fine and has been fine until now.

Only thing we recently changed in this system is getting a new battery 3 days ago. Not sure how could this have to do with it, but it seems likely it's somehow related.

I would guess regulator, but we don't have a spare with us, so our best bet is now limping to where we're going and source parts there. It's 55 miles through the backwoods and ~100 miles going on highways.

So hence the question... we're charging our battery now, when it's full, what are our chances of making it?

Also, anything else that could break if we drive like this? Alternator because it's not under load? Humm...

Just changed out the battery to a new one
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1975 Bus "Big Emma", 1.8 FI, Hydraulic lifters
Interrupting our Pan-American Roadtrip for post-flood repairs: http://www.thesamba.com/vw/forum/viewtopic.php?t=657738
Follow the trip on our blog: http://www.gobigemma.com

[sjbartnik]

If you turn off everything electrical you can run for a few hours pretty easily. If you use anything that sucks a lot of power like headlights or wipers then your range will be drastically reduced.

If in the process of swapping out your battery, you disconnected the battery with the engine running, that could have killed your alternator. Otherwise make sure your battery connections are clean and tight.

Once you start the engine do not shut it off. Starter motor is a big power suck.

If you have carbs you can probably get a little farther than with FI.

If you really need to cover the distance before repair it would not be the worst idea to buy an additional battery that you can swap in if/when yours dies.
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1965 Volkswagen 1500 Variant S
2000 Kawasaki W650

[cmonSTART]

Ya, pop the clutch if you can.

Do you know how many amp*hours the battery is rated for?
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'78 Bus 2.0FI
de K1IGS

[andrewtf]

Since I know this as I have had my head and hands in that engine bay often enough.......

How about this.....

disconnect the aux battery stuff (not the solar) and use some cables (or ?) to run the car off that while you drive.

If it dies, you can switch over to the regular car battery and let the aux battery recharge from the solar.

you .... ~.. might...~.... be able to keep the fridge going with this method?

I say use the aux battery first because you can let it re-charge in leg #2 when the regular battery is being used. and you can switch back to the aux battery if needed. This give you three potential battery uses along the journey instead of just two - if you start wit the regular battery first.
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'75 Riviera - 'BIG EMMA' (Pan American highway trip paused for a make over)
'77 Riviera - Murphy' (being reborn.... slowly)
'63 Austin Healey

[GoBigEmma]

Yeah, sounds like we should give it a go. Weather is still sunny but might get a bit rainy later, so we'll probably hit the road now.

Battery swap was all nominal, no taking-it-out-while-running.

Not sure what the amp hours are, seems like they don't like to print that on starter batteries? Odd. If it helps, it's a Duralast 42-DL.

We'll let you know how this adventure goes, will report later. Cheerio!
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1975 Bus "Big Emma", 1.8 FI, Hydraulic lifters
Interrupting our Pan-American Roadtrip for post-flood repairs: http://www.thesamba.com/vw/forum/viewtopic.php?t=657738
Follow the trip on our blog: http://www.gobigemma.com

[raygreenwood]

I know a bus has more drag and weight than what I am about to list....but the spark plugs do not know that ...four sparks is four sparks!

Year ago when I had a 90 model VW cabriolet...I left Dallas Texas to drive to a little North of Oklahoma city. Total miles about 265.

I was about 10 miles into it and time was short and blew the belt. It was a Sunday day before Thanksgiving....nothing open. I figured I would just drive being daylight and leave everything extraneous turned ...and pick up a belt in Gainesville.

This was with digifant injection and electric cooling fan. Highway speed 70+ mph....at about 3400-ish rpm.

No belt in Gainesville so I bought a spare battery at Walmart. Never had to use it. Drove to my destination and drove to Walmart to return battery in the am and drove to O-Reilly to pick up a belt. All told about 300 miles.....no issues...and about 8 start stop cycles over the whole trip.

You may be surprised how far you can go! Ray

[Spike0180]

I did this in my 97 ford ranger. I was doing great during the day. I had gone about 100 miles. But then I had to turn on my lights, when I did that i was done in about 20 miles. If it gets dark, pull over and camp. Bump start her in the am.

Again, another FI 4 cylinder.
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Brutis Patches Izabich: 1970 VW Transporter - 1776cc DP
Current State: Projects never truly end...
Location: Grosse Pointe, Michigan
Other cars: 2003 F150, 2003 Jetta GLI vr6-6sp

Sambastic: adj; the quality of being nit picky, elitist, expecting everyone to do things the way they believe is best with no regard to situation, "sambastic"

[AlmostHeavenWV_VW]

Finally found the thread I was looking for to help you Emma:

Although that's Robbie's type1....not sure what it'll mean for you guys with your type4 FI set up

[GoBigEmma]

[timvw7476]

250 miles, no radio, lights. (carbed, with mechanical fuel pump)
the injected models you will get 150 or so. Because of electronics.
points ignition doesn't draw a lot of juice.

[GoBigEmma]

Did some diagnostics yesterday, alternator seems like the most likely culprit.

All wiring looks good, spare voltage regulator swap-in didn't fix the issue. Measuring voltage on regulator pins DF and D+ with engine running shows 2.6V and 1.5V, respectively. According to Ratwell, that points to a diode issue in the alternator.

Plan is to get the alternator tested when we're home, but gotta make it home first. It's about 350 miles, so we're probably going to take one or two charging stops at AutoZone and hope that'll be enough to get us home.

I guess that's what it feel like having an electric car...

Anyway, will let you know how this continues, wish us luck getting home today.

Sven
_________________
1975 Bus "Big Emma", 1.8 FI, Hydraulic lifters
Interrupting our Pan-American Roadtrip for post-flood repairs: http://www.thesamba.com/vw/forum/viewtopic.php?t=657738
Follow the trip on our blog: http://www.gobigemma.com

[Jetfxr69]

careful on the pop starting too often. I popped mine on a cross country trip for a week or two, until I snapped a shaft from all the torque. luckily had a shaft under the seat, but then promptly bought a starter
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You can't be a real country unless you have a beer and an airline. It helps if you have some kind of a football team, or some nuclear weapons, but at the very least you need a beer. Zappa

‘77 westy Seamus
‘76 tintop Crusher
‘77 westy The Judge
‘72 tintop bastard westy Hudson

[AlmostHeavenWV_VW]

350 miles is nothing for you guys.

Good luck, but you guys will be okay. Besides, stopping to charge up will give you a good opportunity to take in the local areas.

Not sure if you guys have one, but I carry a 'battery booster' or 'jumper pack' in my bug. Worth a look and consideration. It can sort of revive a battery if necessary in a pinch. Probably would only get <15 minutes of battery, but sometimes that what you need to get to a safe haven for repairs.

I have the Stanley brand, but I've owned others and most brands are good. You can choose a size (and crank amps/amp hours) you prefer and some even come with built in goodies like a USB port, 12v DC port, or air compressor.

https://www.stanleytools.com/products/automotive-tools/power/power-station
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1973 Standard Beetle
1600DP AK case
Solex 34PICT3 Carb
Bosch DVDA 205AJ Distributor

[Slip356]

A couple of years back returning from BNNTA, 600 miles to go to Northern WI my alt light came on. 78 stock westY with FI. Had two newer Optima batteries, one red top Starting and a yellow top.aux each with shut off switches.I carry a dual Battery tender.
Drove about 150 miles on starting battery which went flat, connected aux battery with jumper cables (zip tied them to keep out of harms way) shut off the flat starting battery and made it 150 miles to camp ground with electric. Plugged in tender overnight.
Neither battery was fully charged next morning so left both connected and made it 300 miles home.
Canadian bus with gas heater so have 70 amp alternator that has a plug, not hard wired. Found the plug had worked loose, even with with the stock wire keeper. Have it permanently fastened now.
Hope this helps.
Slip

[TomWesty]

If you replace the alternator, remember the too long alternator stud.
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If you haven't bled on them, you haven't worked on them.
Visit: www.tomcoryell.com and check out my music!

[Abscate]

[Randy in Maine]

Humor me and check the connections at the fuse box for fuse #12.

Make sure it is clean and all good.

[Wildthings]

Last summer I lost the generator in my T-181 Thing about a thousand miles from home. Bought a second battery and ganged it to the first and went merrily on my way for about a week and a half, roll starting whenever possible. Night driving was of course out. When I got within about 300 miles of home and into Les Schwab territory I got them to do a free charge on the battery pair, though I am sure I could have made it another six hours or so of driving. Probably put about 1700-1800 miles on the battery pair before having the recharge done.

[Abscate]

More math electrics

Primary resistance of a points coil AC VW about 4 ohms

So your 12VDC/4 Ohms gives about 3 Amps

Each hour of running is thus consuming about 3 Amps of your 80 Amps - not too bad.

It actually is better than this for reasons I don't want to dwell on.
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.ssS!

[Wildthings]