Mulitmeter help

[muttley383]

looks like a healthy charging system.
To check if the alternator has enough grunt you can turn on all accessories, ie: headlamps on high beam, thermo fans on, aircon on etc. Check that the voltage level is still above the 12.62v with all ancillaries running.

 

[Nanos]

the only true way to test a battery health is to do a load test. You can buy proper load tester from most auto shops.

basicly what a load tester does is put a short across both terminals and shows a voltage reading.

A bad battery may still sho correct voltage on a meter when sitting with no load, but once load is put on it, it will drop fast.

If you want to test load with a meter, turn engine off, turn on as many things as possible, headlights, fans, radio, rear demister, wipers etc... then watch the battery voltage. it should stay around the 12.62 volt mark you mentioned above. if it looks like it is dropping fast and not holding voltage for long, then your battery is need of replacing.

 

[WogBoyz]

kk ill turn everything on the test with my meter again and see how my alternator holds up

how much wud one of these load testers cost? and what they look like btw?

oh and also i cant turn aircon and all of that on with the engine off

"If you want to test load with a meter, turn engine off"

so what ya mean by that?

 

[muttley383]

There are 3 types of battery condition testers.
The first type is your standard battery acid hydrometer.
The second is the load test unit described above. The of the quality of the unit is related to how long you can load the battery down.
The third type is a battery internal resistance checking device. It will give you a reading of number of CCA that it thinks the battery is good for. Compare the result to your batteries specs to determine condition. These units also check charging system condition also.

 

[WogBoyz]

oh ok man to much effort n complicated ill just stick with my multimeter

 

[Garth]

oh ok man to much effort n complicated ill just stick with my multimeter

multimeter is a good indication to see if charging systemn is working,

if you want to test battery health, a multimeter wont do that, as it only reads voltage, (ofcourse some will do amps and other little functions, depending on how much you spend)

buy a hydrometer, they are relitivly inexpensive, and will suite the normal backyard mechanic. it tests the electrolyte in the battery, see weather it's still doing it's thing

 

[WogBoyz]

where do i get that?

and how would i use it? is it like same as testing with the meter

 

[mulligan-can]

where do i get that?

and how would i use it? is it like same as testing with the meter

To use a hydrometer you follow the instructions on the back. Really. That easy.

It just draws in some of the fluid in the battery cell and shows you the specific gravity of it. They usually have a "good range" marked on them. Good indication of battery condition.

A multimeter gives a fairly good view of the condition of the charging system, often not of the battery itself.

If you're that concerned about the state of your battery take it into a shop. Ask them to do a load test on it.

 

[WogBoyz]

oh ok nah im not worried about it i just testing it sorta like a prevention, i can also then check the rest of the familys car to see if there battery is good or on the way out

so do u have to test each cell with the hydometer cus i got 6 lil caps on my battery

also are they much expensive would somewhere like autobarn or supercheap stock them?

 

[mulligan-can]

oh ok nah im not worried about it i just testing it sorta like a prevention, i can also then check the rest of the familys car to see if there battery is good or on the way out

so do u have to test each cell with the hydometer cus i got 6 lil caps on my battery

also are they much expensive would somewhere like autobarn or supercheap stock them?

Yes, each cell does need to be checked. You'lkl have to unscrew each little cap and test each cell. You should also rinse the hydrometer with distilled water after each test to ensure an accurate reading. Usually they'll all be fairly even but occasionally not.

Another good marker for seeing if a battery is still good is it's age. Most (read cheaper) car batteries only last 3-4 years max before they develop hassles.

Also, if the battery has ever been fully discharged it's life will be drastically reduced.