--------------- FIDO MESSAGE AREA==> TOPIC: 246 AUTOMOTIVE Ref: EGN00000 Date: 12/19/97 From: PETER HARLE Time: 04:04am \/To: GARY SPRINZL (Read 0 times) Subj: Re: Battery sizes -=> Quoting Gary Sprinzl to Marc Gerges <=- G'day Gary, I'd like to add some relevant comments to those you made, GS> When an alternator is charging a very low battery, it is maxing out on GS> amps. Like anything electric/electronic, if you leave it running at 100% GS> for an extended time, parts will overheat. Among the parts that can ail GS> if overheated include (but are not limited to) the diodes and voltage GS> regulator. Gary, that's not entirely true, unless the manufacturer indicates that there is a limited duty cycle, the device, whatever it is, should supply 100% output indefinitely, without overheating or sustaining any kind of damage, and that applies to vehicle alternators as well. GS> I take it you have a diesel. Ignition systems typically add a 25-30 GS> amp drain on the charging system. That's 30 amps more than you have on GS> yours. Besides, the alternator in a car is designed to provide more GS> than all of the electrical components in the car will drain (though GS> this is not always the case). However, go adding things like RF That is not indicative of an average vehicle, the total current drain of typical ignition systems (non EFI) is around 3 to 5 amps with the engine idling (decreasing with engine speed unless it's CDI, and they are as rare as hens teeth). An EFI system adds 2 to 5 amps more (mainly due to the fuel pump, the electronics is around 1 to 2 amps max) hence around 5 to 10 amps average. An alternator with an engine idling at around 600 to 800 rpm will typically produce up to 15 amps output, which is more than adequate for most automotive systems. (Alternators on EFI systems may produce more, due the pulley ratio being slightly different). Disconnecting the battery while the engine is running generally won't cause the engine to stop. Although it's not recommended, basically because the alternator regulator attempts to maintain an output voltage with rapidly changing load current components. The battery also acts as a filter (shunt regulator), without it, system voltage may fluctuate, possibly damaging unprotected electronics. GS> Shop manuals recommend charging a battery with an external charger if it GS> has been severely drained of power. Agreed, rapidly charging a typical car battery can generally cause minor damage, particularly if being charged at currents of around 100 Amps. If a battery has been discharged to the point where the vehicle requires "jump starting" then the alternators' output (revved engine) may be high enough (60 to 100 Amps) to cause that same kind of damage. To reduce the possibility of damage, you need to limit the alternators current into the battery. One of the few ways to do that is to divert some of the alternators output current to accessories such as head lights, fans etc for a limited time, eg 30 minutes or so. That way, rather than recharge the battery in 10 minutes at 60 to 100 amps, the charging time will be increased to say 30 minutes, but at a much reduced average charging current of between 20 and 40 amps, generating considerably less heat in the battery. MG> The only way to start another car is with your engine running. If youdon't MG> your battery has to power two starts... GS> So, your battery has to power two starts? That's what SHOULD happen. GS> Starters can draw 2 to 300 amps on a warm engine, more than that cold. GS> Imagine what can happen to a poor little alternator if you attempted GS> to run that much current drain through it. You would have some difficulty getting the average vehicles alternator supplying 200 to 300 amps to the other vehicles battery or starter motor. (Assuming the jumpers leads are correctly connected). Most Alternators rated up to 100A feature inherent current limiting, and providing there is a fan forced air flow through the alternator, (at a max. temp. of 70 deg C for some BOSCH units) they will supply rated current without sustaining damage. I'm happy to connect two vehicles batteries in parallel while one is idling, as no doubt many of you have done. I'd then rev the charging vehicle to around 2000 rpm for several minutes and return to idling before starting the jumpered vehicle. Providing the battery in the idling vehicle was in reasonable condition, there should be little chance of voltage spikes in either system when the other vehicles engine starts and its alternator begins to charge either or both batteries. Disconnecting the leads when both engines are idling should not cause damaging voltage spikes either. The internal resistance of a lead acid battery will generally be so low that any transient is easily absorbed by either battery. If however, either or both vehicles have very poor battery connections, that's a totally different matter. The main danger as I see it, occurs when actually disconnecting the leads from some types of batteries, particularly those with removable vent caps. Resultant sparks may ignite any highly explosive gas built up in the discharged, but charging battery. For this reason I usually pick a good earth point at least some 12" away from the battery vents, so that I can disconnect that point first, any initial sparks are a relatively safe distance from the battery. Works for me, so far so good. Peter H. --- EzyBlueWave V1.20 01fb000b * Origin: Mt.Druitt TAFE +61-2-9839-1310 FidoNet (3:713/709) --------------- FIDO MESSAGE AREA==> TOPIC: 246 AUTOMOTIVE Ref: EGN00001 Date: 12/19/97 From: PETER HARLE Time: 04:58am \/To: JAY EMRIE (Read 0 times) Subj: Battery sizes -=> Quoting JAY EMRIE to TOM WALKER <=- TW>-> connected, and try to start car B. The idea is to use ONLY car A's TW>-> battery and car B's battery and NOT to use car A's alternator. TW>-> Otherwise during starting of car B, you might draw too much current TW>-> through the diodes in car A's alternator and cause a failure. I've TW>-> never seen it happen, but that's the prevailing wisdom. TW> That is really Not Possible. Alternators are Self Limiting as far as TW>Current output goes and WILL NOT basically put out more then their Rated TW>current. The Big problem with Jumpering a Car, Particularly one with a TW>bad battery is Voltage Spikes produced killing one or all of the TW>Alternator Diodes. JE> No, the single most disasterous possibility is the reversal of one set JE> of cables, thus putting reverse polarity on alternator diodes amd JE> blowing them! G'day Jay, I agree with some of what each of you say, most alternators (60A to 100A rating) feature inherent current limiting, and irrespective of the load, won't supply much more current than the rated values (under normal operating conditions including, a discharged battery). I also agree that there is a possibility that you could damage alternator diodes (and stator windings) in the scenario you state, but that is due to the somewhat unlikely, but not impossible event that reverse polarity across the discharged battery (and subsequently across its alternator) is achieved, forcing additional current into that vehicles stationary alternator (forward biased diodes, not reverse biased (G). If the now reversed, "discharged battery" is successfully (completely) discharged and begins to reverse charge, and, its "reverse voltage" manages to rise to several volts, then, any further large current flow from the charged battery could force destructive current flow through the (stationary) alternators' diodes and possibly damage them. This is primarily because the stationary alternator now acts as a low resistance "shunt regulator" with a forward voltage of between two to three volts depending on circuit parameters. The 6 forward biased alternator diodes in series parallel are rated at around 200V PIV and 40A average each, they should survive a current of 200A for a several minutes or so, or at least long enough to cause someone to take notice of the smoke and smell of burning PVC covered jumper leads. Unless of course heavy duty welding cable is used as the jumper cable! The vehicle with its alternator running and attempting to charge both batteries is unlikely to be damaged under this scenario, albeit that it's supplying maximum output, and then only if its engine is revved up. The automobile electrical system is one of the best examples of an environment that generates the worst possible conditions for semiconductor components. Automotive engineers are well aware of this fact and take appropriate steps to ensure that equipment used therein is capable of operating under those conditions, for at least the warranty period ;-), However, reverse "parallel connecting" two batteries is not a design criteria to be met. In short, you would be hard pressed to cause damage, due to voltage transients, by parallel connecting the two vehicles batteries, with or without the alternator running. The overiding proviso being that both vehicles had reasonably good batteries and terminal connections prior to this event. Regards, Peter H. --- EzyBlueWave V1.20 01fb000b * Origin: Mt.Druitt TAFE +61-2-9839-1310 FidoNet (3:713/709) --------------- FIDO MESSAGE AREA==> TOPIC: 246 AUTOMOTIVE Ref: EGN00002 Date: 12/19/97 From: PETER HARLE Time: 05:23am \/To: MARK LOGSDON (Read 0 times) Subj: Battery sizes -=> Quoting Mark Logsdon to Roy J. Tellason <=- RJ> I have a bunch of gels and two RV batteries and a group 34 sitting in RJ> the room here at the moment, that I have to see to every so often. RJ> Like every couple of months or so. One of these days I'm gonna set up RJ> some kind of an automatic charging system for them. ML> Yeah, I just pulled the battery from my lawn tractor for the winter. ML> What I really need to do is to design an electronic regulator for my ML> tractor's alternator. It charges at about 15.0 volts or a little ML> higher and tends to boil the battery dry. G'day Mark, Some motor bikes have a similar problem, the alternator is usually a permanent magnet rotor type with a maximum output of around 3 to 4 amps. That means it's difficult to alter its output easily, without resorting to some kind of active series regulator. Typically using switching or SCR controlled regulator. These alternators are generally regulated by connecting a "shunt regulator" in parallel with their output to dissipate excess energy. That is normally not a problem since their output is limited by circuit characteristics, just like simple bicycle dynamos. The regulator consists of a high power (50 Watt, 14 volt zener specially made for the job and cost accordingly) or, you can "construct" one using an "amplified zener circuit". Basically this uses an NPN power transistor such as 2N3055 and several zeners. Connect the zener combination from collector to base, plus a 120 ohm "bleed" resistor from base to emitter (naturally collector goes to battery plus and emitter to battery minus (G). I mounted the transistor on the outside of a small aluminium box (cigarette pack size) acting as a heatsink, I used 4 x 3.3 Volt, 1W zeners. The unit restricts the alternators output voltage to around 13.8 volts at normal ambient temperatures. GP Silicon diodes (1N914 etc) forward biased, can be used in series with the zeners to trim output voltage in approx. 0.6V increments to whatever you feel is appropriate. The combination approaches the TC of the battery reasonably well, and is considerably cheaper than the $60 "zener regulators" obtainable from "bike" shops. If reverse polarity protection is required, I'd connect a 6 amp diode in series with the collector, it will prevent the base emitter junction being destroyed if the battery terminals are accidentally reversed, a distinct possibility if the battery is removed frequently for storage or bench charging. Regards Peter H. --- EzyBlueWave V1.20 01fb000b * Origin: Mt.Druitt TAFE +61-2-9839-1310 FidoNet (3:713/709) --------------- FIDO MESSAGE AREA==> TOPIC: 246 AUTOMOTIVE Ref: EGN00003 Date: 12/19/97 From: PETER HARLE Time: 05:54am \/To: MARK LOGSDON (Read 0 times) Subj: Battery Terminals -=> Quoting Mark Logsdon to Ronnie Thompson <=- RT> RT> I've never seen a battery with a steel post. Who makes em? RT> RT> ML> What is it they're made of? RT> RT> The only ones I've ever seen were made of lead. ML> That makes sense. I've noticed they're soft metal. I just figured ML> with all the hysteria surrounding lead that they'd have gone to ML> something else. Exactly, it's the application that counts. Lead works with sulphuric acid and is used in "lead lined vats" for electroplating and anodising applications, other materials no matter how a good a conductor, they may be are not be suitable or practical. I've used Platinum electrodes in a brine solution to split water into hydrogen and oxygen, for use in a small welding torch. Isn't it amazing how we manage to skip from one subject to another.(G) Regards Peter H. --- EzyBlueWave V1.20 01fb000b * Origin: Mt.Druitt TAFE +61-2-9839-1310 FidoNet (3:713/709) --------------- FIDO MESSAGE AREA==> TOPIC: 246 AUTOMOTIVE Ref: EGN00004 Date: 12/18/97 From: JAY EMRIE Time: 09:12am \/To: PETER HARLE (Read 0 times) Subj: Battery Size PH>-=> Quoting JAY EMRIE to PETER HARLE <=- PH> JE> I do not understand. Do you read all the messages on line then PH> JE> download them as a QWK pack? I simply get on the BBS, download a QWK PH> JE> package for a predetermined group of conferences and get off the BBS. PH> JE> Usually less than 1-2 minutes. Then I read them all off line. PH> When I logon to the BBS, it informs me of any messages addressed to me nd PH> if I want to read them, I usually do, then download the QWK package, same PH> as you. That's how I knew I had a message from you. But somehow the ailer PH> managed to screw up sending me "that" message. I don't know why, because PH> other messages I had also read "on line", downloaded Ok. I usually only PH> have two or three messages so it's not that much extra time, besides it's PH> only a local non-timed call, and I'm not a prolific message writer as PH> some.(g) Yours then works exactly as mine does. I just save the time,do not read first, just download everything, then read the messages. Call me lazy for not reading them twice! VBG PH>--- EzyBlueWave V1.20 01fb000b PH> * Origin: Mt.Druitt TAFE +61-2-9839-1310 FidoNet (3:713/709) * OLX 2.1 TD * Always proofread to see if you any words out. --- RemoteAccess 2.50+ * Origin: Northern Lights! * San Antonio * 210-499-6299 V34/VFC (1:387/23) --------------- FIDO MESSAGE AREA==> TOPIC: 246 AUTOMOTIVE Ref: EGN00005 Date: 12/18/97 From: JAY EMRIE Time: 09:27am \/To: RON TAYLOR (Read 0 times) Subj: chevy impala RT>(BTW... don't look at my origin line.... I'm in Alabama) RT>--- RT> QMPro 1.02 42-7029 But I DID read the manual... RT> * Origin: Crime Bytes 2 - Underwood, Iowa (712)566-2872 (1:285/12) How do you do that, Please? * OLX 2.1 TD * Two most common elements: Hydrogen & Stupidity --- RemoteAccess 2.50+ * Origin: Northern Lights! * San Antonio * 210-499-6299 V34/VFC (1:387/23) --------------- FIDO MESSAGE AREA==> TOPIC: 246 AUTOMOTIVE Ref: EGN00006 Date: 12/18/97 From: JAY EMRIE Time: 09:32am \/To: RON TAYLOR (Read 0 times) Subj: Chevy Van RT>JE>Ron, not being a Chevy owner I am a bit lacking in knowledge. However, RT> >one of the cardinal rules in trouble shooting problems such as yours is RT> >to carefully check all grounds and connections in the wiring system. RT>Noted. I HATE pulling that inside cowling, but come Saturday, I'll RT>do'er... Start with the wiring connectors and grounds DIRECTLY associated with the ignition and its controls, then as necessary go behind the dash. I specifically remember Chrysler products in the 60s having a similar problem, which turned out to be flaky connection in the 50 plus wiring "through the firewall" connector. RT>JE>Also, the failing after heating up failure and cooling off recovery lso RT> >can be indicative of electronic component failure - ignition module, RT> >ECM, etc. If all else fails I'd consider changing these components one RT> >by one, starting with the cheapest or :-) the easiest. RT>That is what I started when I replace the distributor cap.. figuring it RT>was the most obvious and simplist... now on to the others. RT>Thanks for the hints. RT>--- RT> QMPro 1.02 42-7029 Do you want that on fifty 3's or two hundred 's? RT> * Origin: Crime Bytes 2 - Underwood, Iowa (712)566-2872 (1:285/12) * OLX 2.1 TD * Where does the fire go when the fire goes out? --- RemoteAccess 2.50+ * Origin: Northern Lights! * San Antonio * 210-499-6299 V34/VFC (1:387/23) --------------- FIDO MESSAGE AREA==> TOPIC: 246 AUTOMOTIVE Ref: EGN00007 Date: 12/18/97 From: JAY EMRIE Time: 09:54am \/To: GARY HALL (Read 0 times) Subj: cool cop cars GH> -=> Quoting Mark Logsdon GH> ML> Have you ever heard of the bell curve or gaussian distribution in GH> ML> probability and statistics? Some will fail sooner than others. My GH> ML> father-in-law's 91 Taurus with the AOD failed at about 89k miles. GH> ML> Some people will get well into the 100k mile range or more, but GH> ML> there are many who have never made it to 75k miles. It's such a GH> ML> common failure before 100k miles that many service techs just GH> ML> chuckle when they see an AOD equipped vehicle getting towed to the GH> ML> shop. I've heard the problem is insufficient flow of fluid that GH> ML> Ford later fixed. GH> Yep Ford Fixed it but the Techs you talk about fixed it first. GH> It wasn't insufficient flow it was insufficient volume that GH> caused all the problems. Simply add an extra Quart, and drive GH> the thing. Gosh that's to easy aint' it ? GH> Gary Generic Hall Are you saying OVERFILL the transmission by one quart? GH>... Honey whered ya put ma toothbrush when you used it last ? GH>___ Blue Wave/DOS v2.30 [NR] GH>--- Maximus 2.02 GH> * Origin: Cat House BBS * Tulsa BBS List HQ * (918) 584-3441 (1:170/160) * OLX 2.1 TD * Imagination lets you remember what never happened. --- RemoteAccess 2.50+ * Origin: Northern Lights! * San Antonio * 210-499-6299 V34/VFC (1:387/23) --------------- FIDO MESSAGE AREA==> TOPIC: 246 AUTOMOTIVE Ref: EGN00008 Date: 12/18/97 From: JAY EMRIE Time: 09:43am \/To: ROY WITT (Read 0 times) Subj: Electrical loads, battery RW>16 Dec 97 10:11, JAY EMRIE said this about Electrical loads, battery to MARK RW>SDON. RW> JE> There is an "e" on silicon. :-( Technically I used Dow Corning #4 RW> JE> Compound. (Of course it is silicone. RW>Depends on which one you're talking about. Silicone is a sythentic (Dow Cor RW>s' Compound) and silicon is a non-metalic chemical element. Well, I thought it was rather obvious I was talking about SILICONE when I said "silicon grease". I just can't spell worth a hoot sometimes. :-( Any how it (silicone grease) DOES work superbly as I have described in previous posts. * OLX 2.1 TD * Swallow pride; it's non-fattening. --- RemoteAccess 2.50+ * Origin: Northern Lights! * San Antonio * 210-499-6299 V34/VFC (1:387/23) --------------- FIDO MESSAGE AREA==> TOPIC: 246 AUTOMOTIVE Ref: EGN00009 Date: 12/18/97 From: JAY EMRIE Time: 11:08am \/To: ALAN MORRISON (Read 0 times) Subj: Shake AM>-=> Quoting JAY EMRIE to ALAN MORRISON <=- AM>AM>You can do a few tests before chasing down all the electronics. A eak- AM>AM>down tester, or compression gauge would be best. A vacuum gauge can also AM> JE> I am amazed at how seldom a Cylinder leak down tester is even AM> JE> mentioned. Between a leak down tester, compression tester and vacuum AM> JE> gage a trememdous lot of information can be obtained about an ngine's AM> JE> condition!!! AM>And always place the plugs in order on the air cleaner (or similar) as AM>you take them out. Reading plugs while you have them out gives further AM>clues as to what is going on in each cylinder. Reading the plugs and knowing which cyl they came out of is only simple logic! AM>While I don't own a leak-down tester, watching a Top Fuel crew check AM>out I've had one for about 25 years. an engine between rounds can be an enlightening process. I thought AM>that was a very informed approach, while watching the plugs go into a AM>holed tray atop the intake, with the talkative end up. Then watching AM>the leak-down being timed, and the numbers written down tells me these Timing the leak down?? So one cylinder leaks down faster than the rest. What now? My cylinder leakage tester measures the PERCENTAGE of leakage in a cylinder. ALL cylinders have unavoidable leakage past the rings. IF the leakage is not excessive, then the possible leakages through the intake and exhaust valves and head gasket has to be considered. While the air pressure is constantly being applied, simply listen at the carb throat (pre FI) for an air hiss sound( intake valve leakage). Then at the tail pipe (exhaust valve leakage) then open the radiator cap and listen there and watch for bubbles (head gasket leakage). Tells a mech. a very complete story of the engine. Worth it's weight in gold as a diagnostic tool. * OLX 2.1 TD * When all think alike, then no one is thinking. --- RemoteAccess 2.50+ * Origin: Northern Lights! * San Antonio * 210-499-6299 V34/VFC (1:387/23)