Car Battery Tester Wanted

Status
Not open for further replies.
If I'm not mistaken, a proper battery test is performed under load. Is this little dongle thingy capable of introducing such a load? If not, the results will be no better than what you can achieve with a $5 multimeter from Walmart.
 
That looks like something that works alongside the dummy gauges on the dashboard, only this plugs into the 12v cigar lighter.....so you can have a better idea of how the battery is doing.... IMHO, I'd just take the battery to Walmart, and have them bench test it for you....honestly.... They do it free anyways....they may try selling you a new battery....but unless you REAALLLY want to spend the money on the battery charger (like, if you got a lawn mower, or marine battery that needs ocassional charging...) then I wouldn't worry about buying a battery charger. a) bring the car AND battery into Walmart - they can test the starter, alternator, and battery all at the same time, or, b) carry in just the battery, and they can test your battery only. But, I've found sometimes a faulty charging system (alternator diode(s), starter, etc...) will "take a toll" on an otherwise "good" battery. P.S. if your battery has removable vent caps, check the levels....they should all be about even.....if not, add some distilled water....if you dont happen to have distilled water, filtered BRITA/etc....water will work "in a pinch"...
 
That is not really a battery tester. Ill start out by saying that I have this model and it is the best one on the market. I bought a wal-mart store branded one, and it was so horrible that I returned it after a day. This one has better resolution, better indication of what is going on, improved refresh rate to give better insight with less variability, etc. If you want to really test a battery, see my thread below. You can buy a non-load tester like mine, and determine loss in power (CCA) capacity and rough capacity loss, or you could buy a 500+A carbon pile tester, put a load on the battery, and see how the voltage drops - which provides a characteristic of impedance and thus power again. The former is less abusive to the battery, the latter is indicative of a start attempy. Id go buy a schumacher smart digital battery charger (I like the land and sea or similar name sold at wal mart amongst other places), and really charge the battery fully. This is a prerequisite before any practical testing regardless.
 
Ciggy plugs are very far away from the battery, circuit wise. Through many different connectors all which have measurable resistance and drop the voltage further. Even if voltage was a good indicator of state of charge on a recently charged/discharged battery,which it is not, that device won't really tell you much. Think of an aging battery like a gas tank which just keeps getting smaller. You can still fill it up, it just takes less time to get there, and less time to empty it. And one day, your cell phone charger left plugged in for an hour will be enough to leave you stranded. I'd get the battery tested for free, and save any money on other devices toward a new battery, when the time comes.
 
I see about 0.1V loss, max, on 30 year old cars that I own. Not a big deal, and certainly can be calibrated as such if you just check the loss with a multimeter.
 
If you have an idiot light instead of a gauge this works great for monitoring the alternator output voltage. ( battery charge level) Since there is very little current flow in a voltage metering circuit, voltage drop is almost zero.
 
Originally Posted By: FirstNissan
Hey guys, im looking at getting a car battery tester and I know nothing about the tools out there. I see this on amason: http://www.amazon.com/Equus-3721-Battery...9618&sr=8-2 Im looking for something basic, that will give me a medium-idea of how my battery is doing, and I dont want to spend a ton. Any other suggestions will be great! Thanks
A simple digital multi-meter would do the same as that gadget. Just put it across the battery terminals when ignition off for a base voltage. Start car and do the same. Nominal battery voltage should be 12.6. Car running should show at least 14.2. the multi meter can be used for much more. They are less than 20 dollars at any Radio Trash, or Home Depot, etc. Dave
 
Thanks for all the helpful input! I didnt realize there was so much involved, now its time to readup more on the subject so that im more informed. Im taking my car into Walmart for a free battery test this weekend.
 
As others have said buy a decent multimeter and learn how to use it. It will become one of the most useful tools you ever own. Also if your suspicious of your battery just take it somewhere to get it load tested for free where they can also load test your charging system at the same time as well. That's what I do and Ive been in the Industrial Battery business for a couple of decades now. A load test is the only truly accurate way to test a battery. The resistance testers are useful, reasonably accurate and have their place but they can only give a guesstimate based on an algorithm. A load test again way again to truly be confident that your battery is still serviceable. Again spend you money on a decent multimeter. When you learn how to use it, you then use in conjunction with load tester you already own wink
 
Last edited:
Originally Posted By: 3311
As others have said buy a decent multimeter and learn how to use it. It will become one of the most useful tools you ever own. Also if your suspicious of your battery just take it somewhere to get it load tested for free where they can also load test your charging system at the same time as well. That's what I do and Ive been in the Industrial Battery business for a couple of decades now. A load test is the only truly accurate way to test a battery. The resistance testers are useful, reasonably accurate and have their place but they can only give a guesstimate based on an algorithm. A load test again way again to truly be confident that your battery is still serviceable. Again spend you money on a decent multimeter. When you learn how to use it, you then use in conjunction with load tester you already own wink
A load test is not the only way, but it is one good way. But they should put a load equal to 1/2 of the CCA for 15 seconds and read the voltage, temp compensated. Some load testers are just 50 amps or 100 amps. The newer way is a capacitance battery analyzer. See the other thread in this section.
 
The link for the plug-in says its a battery monitor, not a battery tester. It doesn't mean its totally useless, it looks like it displays voltage at the cigarette lighter plug. Some cigarette lighter plugs are hot, other may have to have the key in ignition position to become hot. You can get a setting voltage before cranking up the engine. Then see the voltage rise (hopefully) once the engine is running. I use something similar to this for my motorcycles but it's not a plug-in unit - Kuryakn (
 
Originally Posted By: Errtt
You can get a setting voltage before cranking up the engine. Then see the voltage rise (hopefully) once the engine is running.
Exactly, I can see voltage drop in real conditions as well as any carbon pile tester can show. Only it is tuned to my engine...
 
Originally Posted By: Donald
Originally Posted By: 3311
As others have said buy a decent multimeter and learn how to use it. It will become one of the most useful tools you ever own. Also if your suspicious of your battery just take it somewhere to get it load tested for free where they can also load test your charging system at the same time as well. That's what I do and Ive been in the Industrial Battery business for a couple of decades now. A load test is the only truly accurate way to test a battery. The resistance testers are useful, reasonably accurate and have their place but they can only give a guesstimate based on an algorithm. A load test again way again to truly be confident that your battery is still serviceable. Again spend you money on a decent multimeter. When you learn how to use it, you then use in conjunction with load tester you already own wink
A load test is not the only way, but it is one good way. But they should put a load equal to 1/2 of the CCA for 15 seconds and read the voltage, temp compensated. Some load testers are just 50 amps or 100 amps. The newer way is a capacitance battery analyzer. See the other thread in this section.
I didn't say it was the only way. I said it is the only truly accurate way. Not to sound rude, but read the post of mine you quoted.
 
Originally Posted By: 3311
Originally Posted By: Donald
Originally Posted By: 3311
As others have said buy a decent multimeter and learn how to use it. It will become one of the most useful tools you ever own. Also if your suspicious of your battery just take it somewhere to get it load tested for free where they can also load test your charging system at the same time as well. That's what I do and Ive been in the Industrial Battery business for a couple of decades now. A load test is the only truly accurate way to test a battery. The resistance testers are useful, reasonably accurate and have their place but they can only give a guesstimate based on an algorithm. A load test again way again to truly be confident that your battery is still serviceable. Again spend you money on a decent multimeter. When you learn how to use it, you then use in conjunction with load tester you already own wink
A load test is not the only way, but it is one good way. But they should put a load equal to 1/2 of the CCA for 15 seconds and read the voltage, temp compensated. Some load testers are just 50 amps or 100 amps. The newer way is a capacitance battery analyzer. See the other thread in this section.
I didn't say it was the only way. I said it is the only truly accurate way. Not to sound rude, but read the post of mine you quoted.
Given that Midtronics sells the newer capacitance testers with some costing over $1000 (and we can assume the large shops are buying them they must feel they are better than a load tester which is much less expensive. It could be that the problem with load testers is that they require the battery to be fully charged. Another way is to hook up a scope with a amp probe attached to a battery cable and start the vehicle. This will tell very accurately what the minimum voltage was during cranking.
 
I have yet to see anything over 13.8 at the battery while running. I have seen 14+ at the alternator while running. I like my 60$ harbor freight tester. For alternator I use a multimeter and assistant.. ie turn on accessories... rev engine to 1500-2000rpm etc. Most cars you can easily put a 60amp+ load on with a few buttons.
 
Last edited:
Originally Posted By: Donald
Originally Posted By: 3311
Originally Posted By: Donald
Originally Posted By: 3311
As others have said buy a decent multimeter and learn how to use it. It will become one of the most useful tools you ever own. Also if your suspicious of your battery just take it somewhere to get it load tested for free where they can also load test your charging system at the same time as well. That's what I do and Ive been in the Industrial Battery business for a couple of decades now. A load test is the only truly accurate way to test a battery. The resistance testers are useful, reasonably accurate and have their place but they can only give a guesstimate based on an algorithm. A load test again way again to truly be confident that your battery is still serviceable. Again spend you money on a decent multimeter. When you learn how to use it, you then use in conjunction with load tester you already own wink
A load test is not the only way, but it is one good way. But they should put a load equal to 1/2 of the CCA for 15 seconds and read the voltage, temp compensated. Some load testers are just 50 amps or 100 amps. The newer way is a capacitance battery analyzer. See the other thread in this section.
I didn't say it was the only way. I said it is the only truly accurate way. Not to sound rude, but read the post of mine you quoted.
Given that Midtronics sells the newer capacitance testers with some costing over $1000 (and we can assume the large shops are buying them they must feel they are better than a load tester which is much less expensive. It could be that the problem with load testers is that they require the battery to be fully charged. Another way is to hook up a scope with a amp probe attached to a battery cable and start the vehicle. This will tell very accurately what the minimum voltage was during cranking.
They are buying for the sake of speed, convenience, idiot proofness and like you said it works on a dead battery. The best conductance meters are only around 90% accurate depending on the battery condition, algorithm and testing method used when determining CCA. It's important to remember that they only give an approximation. A 90% approximation is certainly accurate enough but they can also easily miss diagnose/be fooled by short cell(s). Sending you on a wild goose chase. For the record I have no problem with conductance testers and certainly agree they are useful especially in a high volume shop or if you just want a cool and helpful gadget. But it needs to be understood that they have limitations and will never be as accurate as a load tester.
 
Originally Posted By: Rand
I have yet to see anything over 13.8 at the battery while running. I have seen 14+ at the alternator while running. I like my 60$ harbor freight tester. For alternator I use a multimeter and assistant.. ie turn on accessories... rev engine to 1500-2000rpm etc. Most cars you can easily put a 60amp+ load on with a few buttons.
The difference in voltage your seeing is voltage drop through the circuit, it's normal. 13.8 volts is what you what you to see at your battery. That's a float voltage of around 2.3 volts per cell. Any thing higher for an extended period of time would cook your battery, literally, think lead soup. It's easier than people think with today's automotive batteries and their wafer thin plates, [censored] active material, and poor/minimal plate wrapping. I like your method of testing your charging system. Good stuff!
 
Originally Posted By: 3311
For the record I have no problem with conductance testers and certainly agree they are useful especially in a high volume shop or if you just want a cool and helpful gadget. But it needs to be understood that they have limitations and will never be as accurate as a load tester.
OK.. I have to admit that I just wanted to buy a new gadget (conductive tester). I already have a carbon pile load tester, but its plain Jane, not glitzy.
 
Originally Posted By: Donald
Originally Posted By: 3311
For the record I have no problem with conductance testers and certainly agree they are useful especially in a high volume shop or if you just want a cool and helpful gadget. But it needs to be understood that they have limitations and will never be as accurate as a load tester.
OK.. I have to admit that I just wanted to buy a new gadget (conductive tester). I already have a carbon pile load tester, but its plain Jane, not glitzy.
Maybe not glitzy, but still cool.
 
Status
Not open for further replies.

Similar threads

C
which bleeder cap should i get
Replies
4
Views
686
CarLuver
C
Ni h or li ion battery
Replies
8
Views
617
Snagglefoot
R
Need recommendation on a 10amp battery charger
Replies
17
Views
886
slomo
K
PSA: Harbor Freight compression testers are worthless
Replies
17
Views
4K
jeepman3071
weaponoffreedom
Amalie 0w40 SP
2 3
Replies
48
Views
2K
OVERKILL
Top