Help with Electrical Measurements

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

I guess you are you unhappy with 12.6 after sitting? what was the temperature that state of cahge chart is good for? ushually 25c/75F IIRC, what is the temperature eof the battery when being tested?

the alternator does not know state of charge of the battery, it should put out a reasonably constant voltage, there is some temperature correction in the alternator but it is not that much IIRC,
 
The temperature has been 50 to 80 degrees during testing . The alternator does seem to put out more voltage when the battery is drained a bit. It will charge at 14.5 for about 20 minutes than goes to about 13.5 not sure how it works.
Is it supposed to be constant voltage for a certain rpm?

If the battery is fully charged @ 12.8 you would not want to keep pumping 14.5 volts in to it? Is there a voltage regulator inth the 80 alternator?

You would want to drop the charge down to 13.2 to 13.3.

For this battery they are claiming 12.55 is a 75% SOC for a standard battery 12.6 would be 100% SOC but it is 12.8 for the Lifeline.
 
Battery drain and other stuff

The temperature has been 50 to 80 degrees during testing . The alternator does seem to put out more voltage when the battery is drained a bit. It will charge at 14.5 for about 20 minutes than goes to about 13.5 not sure how it works.
Is it supposed to be constant voltage for a certain rpm?

If the battery is fully charged @ 12.8 you would not want to keep pumping 14.5 volts in to it? Is there a voltage regulator inth the 80 alternator?

You would want to drop the charge down to 13.2 to 13.3.

For this battery they are claiming 12.55 is a 75% SOC for a standard battery 12.6 would be 100% SOC but it is 12.8 for the Lifeline.


cpg:
See this link for neat stuff:

http://homepage.mac.com/dfmorse/RigProj/page1.html

I've been doing this battery drain crap for a few years now, and have come to a tenative conclusion. First, the alternator on the FZJ80 is basic and provides a charge algorithm that does not necessarily match a modern gel cell (dry) battery configuration. For example, my charge voltage upon startup will be about 14.5 to 15.5 volts and battery charge current will jump to about 60 amps, rapidly dropping to around 10 amps; at 10 amps the voltage regulator in the alternator will have reduced the voltage to around 14.3 volts. On a fairly long drive (1/2 hr or more) the voltage across the battery will drop to 13.95 volts and charge current will be 6-8 amps.

My battery specs want to see 12.81 volts for 100% charge. I can achieve this on the bench with a proper charger. However, I have not been able to hold 12.6 - 12.8 volts with the battery in the 80, under normal running conditions. The voltage constantly drops (after engine shut down), implying a drain someplace in the system. I've measure the ECM drain at ~12ma.

I am fairly certain that the alternator reverse current specs plus other drains contribute to the problem we see with our high teck batteries.

I'll be following this thread as battery mods are my obsession.

P.S.; I doubt there is a problem with ur battery.

...
 
dfmorse said:
cpg:

This seems fairly close to what the newer battery wants to see. I was looking into a programable charger until I tested the regulation on the 80. The battery manufacture said that it was fine. Maybe not good enough not sure. I have found the door switches may not close all the way somtimes draining more than it should.


Have you had the battery sit over night disconnected and it still maintains 12.8 volts? Mine will not and it should so I am thinking the battery is bad (not to spec)
battery still starts fine. What do you think?



12 ma is the total drain you have on the entire system?


Even though the charging is not ideal for a AGM battery after a (long drive 8 hours) or after using a charger the battery should be at 12.8. 23 milli amps should not drop the battery to 12.6 should it?


What do you think the difference is between a group 27 and the small batteries you have? Would put to small ones in again?



I will let you know when they check out the batery at the factory.

Very impressive radio how far away can you talk?
 
cpg said:
The temperature has been 50 to 80 degrees during testing . The alternator does seem to put out more voltage when the battery is drained a bit. It will charge at 14.5 for about 20 minutes than goes to about 13.5 not sure how it works.
Is it supposed to be constant voltage for a certain rpm?

If the battery is fully charged @ 12.8 you would not want to keep pumping 14.5 volts in to it? Is there a voltage regulator inth the 80 alternator?

You would want to drop the charge down to 13.2 to 13.3.

For this battery they are claiming 12.55 is a 75% SOC for a standard battery 12.6 would be 100% SOC but it is 12.8 for the Lifeline.

Automotive alternators arte basically single stage chargers, there is to much going on to get into multiple stages of charge, for the lifelines that would be the single stage charging from the text above with a goal of 14.2 to 14.4, at idle they often cannot keep up with the total current load and the voltage sags, when the RPM is up it should find its voltage,

The alternator is internally regulated and as far as I know the only variation is temperature.

13.9–15.1 VOLTS WITH THE ENGINE RUNNING AT 2000 RPM AND 25°C (77°F)
13.5–14.3 VOLTS WITH THE ENGINE RUNNING AT 2000 RPM AND 115°C (239°F)

There is no way for the alternator to know battery voltage nor battery charge current, so it does not know the state of charge of the battery like a high end battery charger would.

Mine when it is working right stays in the low 14's, from the chart above both yours and mine though different would both be within Toyota's acceptable range, but that does not seam to be a tight enough charge voltage to get 100% SOC for a AGM battery.

This morning my main was 12.69v, secondary was 12.92, it is about 80F out there, batteries are probably a little cooler, the main battery did unlock the doors and power the dome light briefly when I opened the door to pop the hood, not sure how much of an effect that would have on getting a good resting battery reading.

0.025 amps parasitic draw should not be an excessive burden, after 16 hours that is .4 AmpHours, should be no bid deal to a 100 AmpHour battery, should still have at least 99.6% of its charge left
 
dfmorse said:
I am fairly certain that the alternator reverse current specs plus other drains contribute to the problem we see with our high teck batteries.

...

Have you found any reverse current in the alternator? In my current check yesterday I found none there, or at least none above 10ma where my meter kicks in.
 
cpg;

My main battery will not hold at 12.8 or 12.6 volts while connected; however, the backup battery is isolated from the system by MOSFET dual battery system (Hellroaring http://www.hellroaring.com/bic75300.htm). Its voltage hangs in there at around 12.6 volts. Is this a clue? I have a spare battery that I use to swap into the cruiser whenever I feel like it. It has been OFF the bench charger, an Interacter II [http://www.interacter.com/] for about a month and the voltage has dropped from around 12.8 to 12.78 volts. If ur battery is new, I would have it checked at factory and maybe they will replace.

I'm not sure of total drain on system;; I'm going to do a battery swap this week and will measure drain to see what I've got. Will have to look up my notes on same to see what I did. I'm using the Odyssey 925 series cuz they were the only ones that fit the box. I would and do replace these batteries on a regular basis and the system seems to be holding up quite well.

Oh, and my first contact with my radio station was Saudi Arabia - works good!


RavenTai;

I haven't done any quality checks on the alternator; its just that its on the main system buss 24/7, so if there was some reverse current leakage, it could be slowly draining the main battery (not the backup); again depending on the temperature. I'm considering going with these guys for a new alternator:

http://www.highoutputalternator.com/HO Alternators Limo.htm

Their quote to me was around $600 plug and play denso 175 amp unit. Just one of my future thought fantasies for crap I don't need.

cheers
...
 
dfmorse said:
Just one of my future thought fantasies for crap I don't need.

cheers
...


LOL I do the same,

you may want to look at this thread, I woudl like to know if the tundra alternator is doable, thet may be a cheaper solution to get a 130A alternator

https://forum.ih8mud.com/showthread.php?t=74878
 
I think this may be a better solution than the higher out put alternator.
It will charge the battery the best way possible. It is not cheap. I am hoping i do not need to go that route.

Raven your battery volts seem good. I would be happy with that.

I called concerned about the 12.6 volts when the battery was brand new.
Now it is droping below that and my draw is only 23ma I think the battery is defective. It is not the draw, maybe it is the battery or the charging system.


Thanks for posting your voltages


http://www.go2marine.com/product.do?no=98209F
 
cpg said:
Okay that sounds good. So the truch is stock with a after market stereo?

No. Stock radio, but added an amp to pump some bass. Sounds like RT's got the info you need (and was probably able to do it without blowing a couple of multimeter fuses :D). So did you all figure out if my readings were abnormally low?

:beer:
Rookie2
 
Rookie2 said:
No. Stock radio, but added an amp to pump some bass. Sounds like RT's got the info you need (and was probably able to do it without blowing a couple of multimeter fuses :D). So did you all figure out if my readings were abnormally low?

:beer:
Rookie2


This time yes, no blown fuse, but I have certainly destroyed my share of ammeter fuses, I keep multiple spares on hand now :doh:

What exactly was your total parasitic draw? I get that the numbers are .1 steady with .2 to .3 at first but not sure on what scale, if that is amps that is a bit high, if it is milliamps you are way below me and CPG.
 
Hey Raven I am pretty sure my battery has a problem. I charged it it 12.8
2 days ago stayed at 12.8 for about 1 hour and has been going down ever since after about 50 hours it is at 12.21 . Disconnect no draw at all.
I cant imagine what would cause this.
What do you think of that Balmar voltage regulator?

1994 80 Draw 27.1 ma
1996 80 Draw 23.1 ma
2002 Camry Draw 14.7 ma
73 FJ 40 Draw 0 ma
 
Down to 12.21? Ouch that is very low, when my alternator acts up my battery gets that low and it is difficult to start.

you probably already know this but I going to say it anyway just in case you do not, the voltage readings as an indicator of state of charge only apply to a battery "at rest" i.e. one that has not been charged or discharged for many hours. If you charged it to 12.8 and stopped it was not fully charged. 12.8 was a surface charge not a state of charge, For instance my batteries will read upper 13v just after shut down and quickly drop, as the voltage approaches its state of charge the drop tapers and slows, in the opposite a discharge will make the voltage drop, when the load is removed the voltage reading will increase towards its state of charge. The longer it rests the more accurate the measure but you can get a decent reading in an hour or two

http://www.uuhome.de/william.darden/carfaq4.htm#measure


If you did fully charge it, and resting for 50 hours it dropped to 12.21 I agree the battery is bad, probably has an internal short. Concorde should take care of it. I have left my dome lights on for near that long, ok maybe 36 hours and granted they are LED but still the battery had plenty left to start the engine, a battery at rest with 12.21 has almost nothing left


I do not know enough about the Balmar voltage regulator to say anything with confidence.

http://www.balmar.net/PDF/2005-mc-612-manual.pdf

Looking at the unit and their description it looks pretty sweet, High accuracy user programmable logic driven voltage regulator for an alternator,

But couple problems,

In skimming that PDF They do not come out and say it but I think it is designed for an alternator with an external regulator, you could probably modify the stock alternator into a an externally regulated unit or use another alternator but that is a bit of work that is not done right gets you back where you started or worse.

Also it is quite expensive, their target customer seams to be marine applications with multiple large banks of batteries that will be heavily charged and discharged.

I am afraid it might be overkill (did I say that?) and that if you had a good working battery and alternator I think you will be happy with the stock regulation,

We may not be wringing the last 10 amp hours that our batteries are capable of with stock Toyota regulation but it should not be a problem under most circumstances.
 
RavenTai said:
What exactly was your total parasitic draw? I get that the numbers are .1 steady with .2 to .3 at first but not sure on what scale, if that is amps that is a bit high, if it is milliamps you are way below me and CPG.

When I first touch the leads (multimeter on the 200mA setting) it starts around 00.3 and settles to 00.1. Multimeter on the 20mA setting it reads 0.01. On the occasion that the cd player triggers and goes through it's shuffle (not every time, kind of hit or miss), the multimeter reading occilates around 3.5 to 3.8 ( on the 200mA setting) or 0.35 to 0.38 (on the 20mA setting). These multimeter readings are strange to me. I would think changing between those settings would be changing the sensitivity, but it seems like it just moves the decimal point.

I assume the 200mA setting is the one that's actually reading in milliamps but again it doesn't make since to me why you'd have to do a decimal shift to translate the 20mA setting. The little owners pamplet indicates 10 microamp resolution for the 20mA setting and 100 microamps for the 200mA setting.

Sorry to be interloping in your thread cpg, but you kind of got me into this :D.

:beer:
Rookie2
 
Last edited:
Raven

After it was charged it was around 13.1 when i disconnected the charger. Hooked a 12 volt compressor up for about 2 minutes to remove the surface charge.

Your comment about the last 10 amp hours is exactly what i thought and maybe losing a little life also. I am hoping it is just a bad battery and no need for a external regulator.

Thanks
 
I assume the 200mA setting is the one that's actually reading in milliamps but again it doesn't make since to me why you'd have to do a decimal shift to translate the 20mA setting. The little owners pamplet indicates 10 microamp resolution for the 20mA setting and 100 microamps for the 200mA setting. [/QUOTE said:
Rookie

A setting of DCA 200m means that the meter is set to measure a maximum of 200 milliamps. If the reading on the meter when is use is 77 then this means that the current is 77 miliamps. A meter setting of DCA 200µ means that the meter is set to measure a maximum of 200 microamps. If the reading on the meter when in use is 77 then this means that the current is 77 microamps.

After reading that i assume that the 20 ma setting reads a max of 20 milli amps.

m is the milli symbol and µ is the micro symbol so it seems that the decimal is changing places. Your reading seems very low I would thin maybe you are in the 10 to 20 milli amp range
 
Years in the biz of servicing Asian autos has taught me that most of those who are not in the biz tend to overanalize things. It is rarely rocket science. If it was we would all be wheeling on moon rocks.
Your draw is not extravagant. Every later model vehicle with onboard computers and stereos will have a draw when shut off. Newer stereos and alarms in older vehicles will do the same. Every system in the truck has a memory that will draw power when turned off.
If your battery will not sustain this for two or more days, you have a problem. If the battery is more than one year old, pull a sheet over it. It is dead. Even if that does not solve it, a new battery is good. That is what warranties are for.
Since the late 60's or early 70's low level shorts in electrical systems have been a thing of the past, unless they are caused by some kind of body damage. They still happen, but it is rare.
British cars are the exception, but few have ever accused the British of automotive excellence.
Replacement stereos and other aftermarket systems are not always installed by rocket scientists. They can cause problems. When searching a problem, remove power from all alarms, stereos, etc.
Then see if you still have a problem
 
Rookie2 said:
I would think changing between those settings would be changing the sensitivity, but it seems like it just moves the decimal point.
:beer:
Rookie2


That is what I would think also, a miliamp is still a miliamp weather you are looking ar 200 or 20 the decimal point should not move, but I agree with CPG, comparing to what we expect to see you must be getting the 10 to 20 miliamp draw witch is nice,
 
RavenTai said:
That is what I would think also, a miliamp is still a miliamp weather you are looking ar 200 or 20 the decimal point should not move, but I agree with CPG, comparing to what we expect to see you must be getting the 10 to 20 miliamp draw witch is nice,

Any other quick and easy places I could hook up and check, that has a known draw so I could back check to make sure how my meter is reading. I.e. would have a smaller number of loads and a no-brainer draw.

Thanks RT.
 
Rookie2 said:
Any other quick and easy places I could hook up and check, that has a known draw so I could back check to make sure how my meter is reading. I.e. would have a smaller number of loads and a no-brainer draw.

Thanks RT.


I think I found something that can help, you have an LX450 with the stock CD changer as do I, when mine was cycling it was reading 0.35 amps (350mA), you said you got 3.6 on the 200ma range, assuming our CD changers take about the same current and one woudl not take 10 times as much as the other it looks like the 200 mA range displays in deci-amps, so therfore 3.6 tenths of an amp = .36A = 360 mA

"When I first touch the leads (multimeter on the 200mA setting) it starts around 00.3 and settles to 00.1."

so if I am right .1 deci-amps must be .01 amps or 10 miliamps.

10 miliamps is about 10ma lower than what CPG has been seeing in Toyota vehicles but I think both my and your meter are at the very bottom of their sensitivity.

but here is where I run into a problem, folowing this logic assuming that the makers of your meter although not intuitive would be at least consistant, you woud think that switching over to the 20ma range it would move the decimal point right once more and start displaying in centi-amps, but it does not? it seams to move the decimal point left and displays amps? :confused:


"the multimeter reading occilates around 3.5 to 3.8 ( on the 200mA setting) or 0.35 to 0.38 (on the 20mA setting)."

on a simialr note a friend of mine has a lower end "user fliendly" dmm, it only has 4 buttons you pick volt ohms or amps and it does the ranging for you automatically witch would be nice if it would bother to tell you the scale it ws using I was testing out his TPS whith it the other day (Jeep CJ5 with GM TBI conversion) , when you approach where it needs to swich ranges lats say 500 ohms it goes ahead and switches over the display to kiliohms ".5" ok thats fine but it fails to give you a "K" on the side of the display, that meant I had to keep track, If I was testing soemthing that did not sweep, like resistors it would be dificult to use, for instance a 100,000 ohm resistor and a 100 ohm resistor would look identical on that display than they are quite diffrnet resistors :mad:
 

Users who are viewing this thread

Back
Top Bottom