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Discussion Starter · #21 ·
The only water I usually have to add or most of the time even charge are my deep cycle marine batteries. If the battery is way down at the beginning of the season I use an automatic 10 amp charger for 16 hours. The amps go down the less it needs. I've been doing this for 40 years and it's never hurt them before. The only time I charge the vehicles is if I have some kind of charging system failure or someone leaves the lights on. As far as cleaning? I was referring to the battery posts, surely you understand those need to stay clean. I stand by my statement, batteries are not as good as the old days. Take that meter of yours and go into a auto parts store or Costco and look for yourself.
 

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Njuneer
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The only water I usually have to add or most of the time even charge are my deep cycle marine batteries. If the battery is way down at the beginning of the season I use an automatic 10 amp charger for 16 hours. The amps go down the less it needs. I've been doing this for 40 years and it's never hurt them before. The only time I charge the vehicles is if I have some kind of charging system failure or someone leaves the lights on. As far as cleaning? I was referring to the battery posts, surely you understand those need to stay clean. I stand by my statement, batteries are not as good as the old days. Take that meter of yours and go into a auto parts store or Costco and look for yourself.
No doubt battery life and quality has taken a dive, mostly because the typical person has no clue about what makes a good battery, and bullshi** marketing rules. "this one is cheaper" is all anyone says. If you didn't realize, I can pull a 700ah battery off the shelf and mark at 850ah, and you will never know the difference!!! that is a fact!

I got into this with Sams. Told them their batteries were junk. they didn't expect me to show up with my engineering crew and meters to prove it! In the end, they gave a full credit towards what junk I wanted to buy....lol NEVER a refund, though I probably could have got that. Always be the smartest guy in the room. they didn't appreciate what I did. Customers watched and filmed.

But if you are charging batteries with a "10A charger for 16h", I assure you, you are doing it wrong. upgrade to a real regulated charger. Voltage is important, those batteries will take all the amps you can feed them.
 

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Discussion Starter · #23 ·
Hey, great job by the way as to sticking it to what I believe is Sam's Club. Sometimes you have to stick up for yourself even though in the long run it doesn't do any good. Would have liked to have been there. I'll keep all of this in mind and thanks again for the multimeter stuff.

Cheers,
Matt
 

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Discussion Starter · #24 ·
LOL, you possibly just popped the exact fuse I warned you about! When you first put a battery cable on, it lights up the computers, charging up capacitors, and current draw can get high for a moment, which is exactly why I mentioned the jumper technique.

Now you need to see if the meter has a fuse and if you blew it. For meter, one lead on the 10A term, other on common (middle)0 term. Measure in series between batt post and cable end. See if meter is blown first, then we can move forward.
Hey Viper, hey got the new fuses and I am going to test tomorrow or so with your method. You obviously know more than I and I appreciate your help. Couple of questions though just so my brain can understand. YouTube has two or three guys who do it without the jump wire. How are they doing that? They have cheap meters and are using the 10 amp max. Also, when you pull the jump lead why doesn't it just draw more power across my leads and blow the fuse again? Is it because all these circuits are charged up and don't recharge until they loose all power? Just trying to get my head around this. Here is one of the YouTube's and it's about 1/3 up the video...maybe a little less. Hope you doing well.

 

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Njuneer
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What I explained to you is the "safest" way for your meter. If you want to roll the dice like these other dudes, be my guest, but I have spent many hours in a classroom educating techs on stuff like this and I am not wrong.

I explained why a system may pull higher amps when first hooked up above. You did not follow it. In short, there can be many reasons, but one is called "capacitor charging". When first applying DC to a capacitor, it acts like a dead short for a brief moment. Consider it like filling up a glass of water with a fire hose. Once it is full, it cannot take any more.

Computers are full of them, and cars are full of computers. This is only one reason. Cars can also activate certain alarm and self check features on powerup.

Do you "have" to use a jumper? NOPE! If you have several fuses to blow, and a cheap meter, be my guest.

BTW, if you want to go with that method, I recommend you disconnect the batt lead, and get your meter on very quickly. Many times capacitor systems will also use "bleed resistors" that basically slowly discharge any spare charge in a system over a slow period of time of a few minutes. So reconnecting quickly will usually reduce risk of over current on the meter.

Or you get all fancy and install a series NTC thermistor.....lol I'm kidding. Way too involved in electronics.

You can also just install a hoop of wire at the base of a batt stud with a short lead, connect one meter lead to that. Then connect (clamp) your other other meter lead to the battery cable somehow. All this before you disconnect the cable. No jumper needed. many ways to do this. I provide the safest for your meter.
 

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Discussion Starter · #26 ·
What I explained to you is the "safest" way for your meter. If you want to roll the dice like these other dudes, be my guest, but I have spent many hours in a classroom educating techs on stuff like this and I am not wrong.

I explained why a system may pull higher amps when first hooked up above. You did not follow it. In short, there can be many reasons, but one is called "capacitor charging". When first applying DC to a capacitor, it acts like a dead short for a brief moment. Consider it like filling up a glass of water with a fire hose. Once it is full, it cannot take any more.

Computers are full of them, and cars are full of computers. This is only one reason. Cars can also activate certain alarm and self check features on powerup.

Do you "have" to use a jumper? NOPE! If you have several fuses to blow, and a cheap meter, be my guest.

BTW, if you want to go with that method, I recommend you disconnect the batt lead, and get your meter on very quickly. Many times capacitor systems will also use "bleed resistors" that basically slowly discharge any spare charge in a system over a slow period of time of a few minutes. So reconnecting quickly will usually reduce risk of over current on the meter.

Or you get all fancy and install a series NTC thermistor.....lol I'm kidding. Way too involved in electronics.

You can also just install a hoop of wire at the base of a batt stud with a short lead, connect one meter lead to that. Then connect (clamp) your other other meter lead to the battery cable somehow. All this before you disconnect the cable. No jumper needed. many ways to do this. I provide the safest for your meter.
Hey I believe you. Your so detailed it's obvious that you know your stuff. I just though it odd that three YouTubers never warned for that. I did do it pretty fast so not sure why it blew but I faintly remember playing with that some time ago and might have blown it then. Another thing comes to mind is again that 1995 Ford f250 doesn't have much electronics (one computer) so I can only assume it wouldn't pull to many amps. So last question at least for now, if the diode went out in my alternator would that pull more than 10 amps thus blowing my fuse again? I consider myself a researcher and a thinker. I also follow the wisdom of someone who has more experience than me and you clearly do. Thanks again for your input and I plan to do the test soon.
 

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Njuneer
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Hey I believe you. Your so detailed it's obvious that you know your stuff. I just though it odd that three YouTubers never warned for that. I did do it pretty fast so not sure why it blew but I faintly remember playing with that some time ago and might have blown it then. Another thing comes to mind is again that 1995 Ford f250 doesn't have much electronics (one computer) so I can only assume it wouldn't pull to many amps. So last question at least for now, if the diode went out in my alternator would that pull more than 10 amps thus blowing my fuse again? I consider myself a researcher and a thinker. I also follow the wisdom of someone who has more experience than me and you clearly do. Thanks again for your input and I plan to do the test soon.
Those diodes usually fail open, as in no worky at all. An alternator that has parasitic draw can usually be upgraded, depending on model. Like the old 10SI can use a marine regulator if I remember right. Very much depends on how much draw. I would want number before making a decision. be prepared to take the alt lead off under testing to confirm a draw there. Probably make that your first disconnection point.

As for the old Ford, old ECMs actually pulled more power than new ones. As you know, efficiency in computing has changed a lot. I guaranteed if I opened that Ford ECM, and a brand new Toyota, it would blow your mind. Like 1/4 of the size, and probably 1/4 of the power requirement.

Don't let the vehicle age fool you, and also stop over thinking this. This testing can be done in minutes. Once you do it, you will realize.

If you are extra worried about too much draw to the meter, you can install a headlight bulb in series with the meter leads. We use bulbs all the time as they function as a current limiting resistor. Basically an PTC though. As current increase, the bulb gets bright and limits current. This can protect your meter from hitting 10A. Once you can confirm the range your meter is likely to test in, you can then get rid of the bulb. With it in circuit, you cannot get a super accurate current draw.
 

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Discussion Starter · #28 ·
Those diodes usually fail open, as in no worky at all. An alternator that has parasitic draw can usually be upgraded, depending on model. Like the old 10SI can use a marine regulator if I remember right. Very much depends on how much draw. I would want number before making a decision. be prepared to take the alt lead off under testing to confirm a draw there. Probably make that your first disconnection point.

As for the old Ford, old ECMs actually pulled more power than new ones. As you know, efficiency in computing has changed a lot. I guaranteed if I opened that Ford ECM, and a brand new Toyota, it would blow your mind. Like 1/4 of the size, and probably 1/4 of the power requirement.

Don't let the vehicle age fool you, and also stop over thinking this. This testing can be done in minutes. Once you do it, you will realize.

If you are extra worried about too much draw to the meter, you can install a headlight bulb in series with the meter leads. We use bulbs all the time as they function as a current limiting resistor. Basically an PTC though. As current increase, the bulb gets bright and limits current. This can protect your meter from hitting 10A. Once you can confirm the range your meter is likely to test in, you can then get rid of the bulb. With it in circuit, you cannot get a super accurate current draw.
Okay, thanks for the lesson. The fuses came in a six pack so I'm going with the jump wire technique and then jump to the bulb method if it blows the fuse. Might be that I have no draw at all and just have a weak battery.
I'll let you know how it works out.
 

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In good old days, without fancy tools, I simply used one of spare car fuses (10 or 20 Amp) to test the leaking current. It is only 12 volt so it wont kill you, but the heat from thermal fuse might burn you fingers, so use gloves.
 

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Discussion Starter · #30 ·
In good old days, without fancy tools, I simply used one of spare car fuses (10 or 20 Amp) to test the leaking current. It is only 12 volt so it wont kill you, but the heat from thermal fuse might burn you fingers, so use gloves.
No way to read the amps but if it blew you knew something was going on?! Old school
 
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