car jump starters, any advice on which one?

[Crash2510]

I have used a large heavy duty jump starter on a large bucket truck and it turns it over no problem. It can be used multiple times per charge and also includes a light flashers and small air compressor but only weighs 10 to 15 pounds.

[SteveJ]

That is why I mentioned Saab, they actually have a proceedure to drain the radio memory as it's just a capacitor, then you can do the test. I stll am able to use this test on vehicles, and most of the ones I work on are post 85 fuel injection.

How does this work? Wouldn't the memory be in the radio? The capacitor is there to provide a steady current to the radio and it would have to be discharged, but this is separate from the radio's memory, or, is that what you meant?

Steve

[billwmeyer]

Mike,
I am with some of the others here. There is nothing worse it seems, than battery problems. I would get it tested and fix it right. Unless you have access trouble, an alternator is a simple replacement. If the alternater and battery are sound, look for the draw.

Good luck!

Bill

[Russianwolf]

I will be having it checked this weekend, but I have confirmed that the Battery on is rated for 450 CCA and 525 CA. Fine for a little honda, but not really enough to cold start a V-8.

Once I confirm that both are okay, I'll upgrade the battery to an Optima with 800 CCA. Then I'll add the Marine switch at some future date and upgrade to a better Alternator at that time also.

But the first thing I want to do is have the front brakes checked over and see if they need anything. Stopping is more important than starting. Rear brakes will come alittle later.

Funny. I paid $600 for this truck and I sat down yesterday and made a list of what I think it needs and what I want. I think I'm going to end up putting about $3k into this rig before I'm done.

Brakes $300
Battery/alt $200
Tune up/upgrade to Electronic Ignition $100-300
Take care of the rust $250
Paint ?? $500 ??
New seat $200-300
New rear window $150
New bumpers ?? $500 ??
New wheels and tires $400
Odds and ends $100

But I'll have her purring like a kitten and looking good.

[LinuxRandal]

How does this work? Wouldn't the memory be in the radio? The capacitor is there to provide a steady current to the radio and it would have to be discharged, but this is separate from the radio's memory, or, is that what you meant?

Steve

I'd have to get the book back from my boss. I bought it for trying to trace down his "electrical problems", which were effectively of his own design. He kept saying the car wouldn't start, so he thought it had an unusual draw, and I was using my multmeter (OTC 3545) to try to calculate what the draw was. Another friend, who has a Saab (and is a machinist/hot rod shop) had the factory manual for his, and told me about the book I picked up. It had something to do with disconnecting the battery cable, then hooking back up (for something like 30 seconds) then disconnecting it, as it would provide power for that bit, then start getting recharged.
As for the newer cars, they use a type of flash ram (like what is in a USB key) to keep the computers memory. Which is why you need the OBD and CAN compliant machines to reset those.
As for the PITA Saab, after I finished tightening the battery cable (I told him he was smart enough to replace it) that he hadn't, soldering the connection that he barely crimped, and turning off the dome lights, he had no problems. Untill he decided to wait 4 months between restarting the car (toy), now he thinks it has another draw, because it can't sit unstarted that long. I am hoping he doesn't have me go back over every little stretch of wire, checking continuity and all that again.

[billwmeyer]

Quote:
Brakes $300
Battery/alt $200
Tune up/upgrade to Electronic Ignition $100-300
Take care of the rust $250
Paint ?? $500 ??
New seat $200-300
New rear window $150
New bumpers ?? $500 ??
New wheels and tires $400
Odds and ends $100

But I'll have her purring like a kitten and looking good.
__________________
Mike


Having a truck you know you can depend on....
Priceless!!

Bill

[SteveJ]

I'd have to get the book back from my boss. I bought it for trying to trace down his "electrical problems", which were effectively of his own design. He kept saying the car wouldn't start, so he thought it had an unusual draw, and I was using my multmeter (OTC 3545) to try to calculate what the draw was. Another friend, who has a Saab (and is a machinist/hot rod shop) had the factory manual for his, and told me about the book I picked up. It had something to do with disconnecting the battery cable, then hooking back up (for something like 30 seconds) then disconnecting it, as it would provide power for that bit, then start getting recharged.
As for the newer cars, they use a type of flash ram (like what is in a USB key) to keep the computers memory. Which is why you need the OBD and CAN compliant machines to reset those.
As for the PITA Saab, after I finished tightening the battery cable (I told him he was smart enough to replace it) that he hadn't, soldering the connection that he barely crimped, and turning off the dome lights, he had no problems. Untill he decided to wait 4 months between restarting the car (toy), now he thinks it has another draw, because it can't sit unstarted that long. I am hoping he doesn't have me go back over every little stretch of wire, checking continuity and all that again.

Thanks for the explanation. The FlashRam memory should have lost its contents just as soon as the battery died because flashRam needs constant power. .......Steve

[mpc]

If you do go with two batteries... some ideas to consider from the RV world:

RVs almost always have multiple batterys - a "house" battery for the interior/living stuff and a "chassis" battery to start the engine and do the other "car" stuff. One big alternator charges both batteries through a "battery isolator" module. This module is something like a "Y" cable: 1 input (from the alternator) and 2 outputs. The difference: the two outputs don't see each other... the "house" lights won't steal power from the chassis battery. The isolator is really just two big diodes in a heat-sink case and it's readily available at any RV shop. CampingWorld.com sells them too.

Another trick RVs use: having separate batteries is great - you don't have to worry about no-start issues if you leave the bedroom lights on for example. But what if the chassis battery dies for some reason? Wouldn't it be nice to "jump start" from the house battery? Using a standard "remote starter solenoid" found on many Ford/GM vehicles you can "jump" the two batteries together with a pushbutton switch on the dash. The button triggers the solenoid (really just a very beefy relay) coil, the switch contacts then connect the battery "+" posts together. Now the house battery jump-starts the vehicle from the driver's seat - no cables, no muss, no fuss. And nobody has to know you've got a dead chassis battery! Some RV's refer to this as the "boost" solenoid by the way.

mpc

[LinuxRandal]

Thanks for the explanation. The FlashRam memory should have lost its contents just as soon as the battery died because flashRam needs constant power. .......Steve

No they don't need constent power! Do you have a USB KEY? It wouldn't be a good memory stick, if it lost your data, when you unpluged it to take it to another system.

[jlake1998]

Intermittly turning over slow can be attributied to a loose fan belt. Just not quite taungt enough will do it. I have had this happen on older vehicals with v-belts

[SteveJ]

No they don't need constent power! Do you have a USB KEY? It wouldn't be a good memory stick, if it lost your data, when you unpluged it to take it to another system.

Memory sticks use "Flash" memory which will preserve its data after the power has been removed.

Car Radios use "Flash Ram" which needs a constant source of power or the data is lost. Even when the car is turned off the Flash Ram is pulling in a few milliamps of current so it can preserve it's data. If the car's power is completely lost, then the Flash Ram will lose its data. That's why the radio loses its presets when the battery dies.

[jziegler]

I've never heard of anything called "flash RAM" and I'm an electrical engineer that deals with many things digital. What you describe sounds to me like SRAM, which is static RAM. The only flash that I'm familiar with is the non-volatile type used in USB keys and the like. Now, I could be wrong on this, but in my work, this is my experience.

Sorry to continue dragging this off the original topic.

Jim

Memory sticks use "Flash" memory which will preserve its data after the power has been removed.

Car Radios use "Flash Ram" which needs a constant source of power or the data is lost. Even when the car is turned off the Flash Ram is pulling in a few milliamps of current so it can preserve it's data. If the car's power is completely lost, then the Flash Ram will lose its data. That's why the radio loses its presets when the battery dies.

[SteveJ]

[QUOTE=jziegler]I've never heard of anything called "flash RAM" and I'm an electrical engineer that deals with many things digital. What you describe sounds to me like SRAM, which is static RAM. The only flash that I'm familiar with is the non-volatile type used in USB keys and the like. Now, I could be wrong on this, but in my work, this is my experience.

Sorry to continue dragging this off the original topic.

Jim


Thanks Jim. I agree we're getting too far off topic. FlashRam is another name for Flash memory. It's non-volatile and includes battery (IE car radios) powered RAM. It gets its name from the access method which is by block as opposed to byte. At least, I think that's what it is. <grin>


Steve

[SteveJ]

Jim: Looking over my last post I think it might have added more confusion than it cleared up so I'll give it another try. As I know it, Flash Ram is similar to Flash memory, in that they are both accessed by blocks of bytes instead of by the single byte. The difference is, Flash Ram is volatile and has to have some power to retain its contents; thus the loss of the radio presets when the battery dies.

The earlier confusion is common because since the car radio draws a small amount of current even when the car is turned off, most people think it has flash memory but actually it has Flash Ram and will lose its contents as soon as there is an interruption power.

Steve