[wofannin]

Hi friends, I went to have my battery tested on account of suggestions that some remaining electrical issues might be related (we fixed the big issues thanks to this forum 🙏🙏).

The person helping me said it's time for a new one, that this one could start giving major problems at any time. I just wanted to get some opinions here before I did that.

Here is the reading (hopefully the language difference is not an issue). He was saying the 669 should be above 910.

Thanks!!!

 

[SaVAGeSoot]

Well my Spanish is junk, but I'm not color blind and know enough to say that it clearly states it's good and only needs a recharge. How's your eyesight and Spanish?

 

[wofannin]

Well my Spanish is junk, but I'm not color blind and know enough to say that it clearly states it's good and only needs a recharge. How's your eyesight and Spanish?

ha. yeah i saw that ... he said the level is actually low though ... so i guess I'm looking for someone that understands these numbers more ... thanks for responding though!

 

[SaVAGeSoot]

He's trying to rip you off. The midtronics tester does some fancy measurements and determines if the battery can be recharged, hold a charge, etc. Based on that, it prints out a report. When it determines that your battery is junk, it tells you that and it tells you to replace it. Avoid this "mechanic" and put a nice strong charger on the battery.

If you search hard enough, you can find documentation that outlines how a battery should be tested based on different vehicles, etc.

 

[wofannin]

He's trying to rip you off. The midtronics tester does some fancy measurements and determines if the battery can be recharged, hold a charge, etc. Based on that, it prints out a report. When it determines that your battery is junk, it tells you that and it tells you to replace it. Avoid this "mechanic" and put a nice strong charger on the battery.

If you search hard enough, you can find documentation that outlines how a battery should be tested based on different vehicles, etc.

thank you!

 

[SaVAGeSoot]

Here's a quick read as a generic guide.... I can't come across the one that actually has sample printouts at the moment.

https://static.nhtsa.gov/odi/tsbs/2019/MC-10158529-9999.pdf

 

[rgh0]

Electronic battery testers send a high frequency signal through the battery and measure the battery impendance which can be correlated to the remaining battery capacity based on the input of the new battery Amp hours capacity. They need to be connected directly to the battery terminals with the battery disconnected for best results but most have a setting for the device if the battery is still connected to the car. you need to connect the device to the battery temrinals directly but this is hard for a quick test in a Treg with it under the seat

As you will read in the guide that Soot attached it recommends direct attachment to the batteries. It also says that if you measure a Treg from the terminals in the engine bay you need to reduce the new battery capacity setting to get an acceptable calculation of remaining battery capacity. This becasue wiring to the battery affects the impedance measured

 

[wofannin]

Electronic battery testers send a high frequency signal through the battery and measure the battery impendance which can be correlated to the remaining battery capacity based on the input of the new battery Amp hours capacity. They need to be connected directly to the battery terminals with the battery disconnected for best results but most have a setting for the device if the battery is still connected to the car. you need to connect the device to the battery temrinals directly but this is hard for a quick test in a Treg with it under the seat

As you will read in the guide that Soot attached it recommends direct attachment to the batteries. It also says that if you measure a Treg from the terminals in the engine bay you need to reduce the new battery capacity setting to get an acceptable calculation of remaining battery capacity. This becasue wiring to the battery affects the impedance measured

we did connect it to the battery under the seat not sure if that changes anything.

 

[wofannin]

Here's a quick read as a generic guide.... I can't come across the one that actually has sample printouts at the moment.

https://static.nhtsa.gov/odi/tsbs/2019/MC-10158529-9999.pdf

and friend ... total dummy question here ... but i've never charged a battery that of a car that is driving fine so i just want to be clear that this is what we are talking about.

so i will be taking it to a mechanic to just charge up for a few hours via their charging tool (according to the instructions in the document you sent), is that what we are talking about doing?

 

[SaVAGeSoot]

Just make sure this mechanic is not the same one that's telling you to replace the battery while holding the diagnostic tester which tells everyone to simply charge the battery.

A high end charger is required for best results ($2k for proper VAS tool). If doing it at home or Mickey mouse style, find a smart charger with a high output. Your typical 10-15a generic ones will not get you full charge. The VW one can do something silly like 90a or so.

 

[wofannin]

Just make sure this mechanic is not the same one that's telling you to replace the battery while holding the diagnostic tester which tells everyone to simply charge the battery.

A high end charger is required for best results ($2k for proper VAS tool). If doing it at home or Mickey mouse style, find a smart charger with a high output. Your typical 10-15a generic ones will not get you full charge. The VW one can do something silly like 90a or so.

THANK YOU!!!

 

[rgh0]

we did connect it to the battery under the seat not sure if that changes anything.

For most accurate results you need to disconnect the battery from the car and directly measure it at the terminals

 

[SaVAGeSoot]

Here it is.... I had to dig for a sample printout of a proper battery test\charge because it was really eating me not being able to find it. Note how it has all the pertinent information on the result.

 

[Dannyboy485]

A high end charger is required for best results ($2k for proper VAS tool). If doing it at home or Mickey mouse style, find a smart charger with a high output. Your typical 10-15a generic ones will not get you full charge. The VW one can do something silly like 90a or so.

I agree. Also the biggest issue I noticed since I came to North America is alot of people use manual buzz box chargers which destroy batteries. They aren't great at detecting what state of charge battery is in and will often boil flooded batteries and destroy AGMs. Digital/smart versions are much better for actual charging rather than boosting.

I've got a crappy tire 25A "smart" version and it's actually very good at detection and charging rate. I noticed batteries that are toast will cause the charger to cycle on and off constantly so it's easy to know if the battery is pooched or not.