Capacity Tester question

[hightecrebel]

ETA: I'm talking form-factor - small, sealed, integrated display/printer - not 'get all the info in a few seconds'.

Before the wall of text, here's the question: Any battery capacity/load testers out there like the auto battery ones that are hand-held with an integrated printer?

Ok, so I'm looking at a chance to get some used cells for a song, but I want to make sure I know what I'm getting as opposed to just tossing them together willy-nilly. I've never gone the used cells route, so I haven't done any real capacity or load testing, and really don't intend to go crazy with it, so I don't see a need to drop a couple hundred on the quality ones, nor do I want to lug a laptop around to get the data, and the area I'll be doing this in is far from laboratory clean, so an open circuit board gives me all the heebie-jeebies. I've used ones for lead acid batteries for years that let me check everything and print it off, are there any like that for lithium batteries or I just need to bite the bullet and get myself a good one?

 

[sunshine_eggo]

Before the wall of text, here's the question: Any battery capacity/load testers out there like the auto battery ones that are hand-held with an integrated printer?

Ok, so I'm looking at a chance to get some used cells for a song, but I want to make sure I know what I'm getting as opposed to just tossing them together willy-nilly. I've never gone the used cells route, so I haven't done any real capacity or load testing, and really don't intend to go crazy with it, so I don't see a need to drop a couple hundred on the quality ones, nor do I want to lug a laptop around to get the data, and the area I'll be doing this in is far from laboratory clean, so an open circuit board gives me all the heebie-jeebies. I've used ones for lead acid batteries for years that let me check everything and print it off, are there any like that for lithium batteries or I just need to bite the bullet and get myself a good one?

No. You were not getting capacity tests with that lead acid tester. You were getting ESTIMATES of cold cranking amps and/or capacity based on calculations based on voltage and internal resistance measurements.

Nothing can test capacity without fully charging and discharging.

A YR-1035 tester can provide both voltage and internal resistance (impedance) measurements - it's the same measurement provided on cell datasheets.

There are relatively inexpensive capacity testers that will discharge a cell and provide the Ah/Wh values.

Battery Capacity Testers

I make a commission for purchases made with the links below

www.mobile-solarpower.com

 

[jimf909]

So my X-Ray vision glasses won't work? Darn it all.


The OP's question is something I was wondering about too.

 

[12vDC]

handheld with a printer? interesting…

a relatively inexpensive method to test battery capacity is with a basic meter.

Bidirectional Volt Amp Meter, DROK DC 0-90V 300A Voltage Current Battery Capacity Amp-Hour Watt-Hour Power Time 7-in-1 Monitor Tester Color LCD Display Multimeter with Hall Sensor 50cm Shielding Wire https://a.co/d/2h92aPJ

i recently used this one with success. as mentioned above you have to provide your own load draw.

 

[Warpspeed]

As already stated, the only way to know for sure is a proper full discharge test with the proper equipment.

The idea that you can just poke at a cell for one second, then have something that prints out a full two page test report is just science fiction.

 

[12vDC]

As already stated, the only way to know for sure is a proper full discharge test with the proper equipment.

The idea that you can just poke at a cell for one second, then have something that prints out a full two page test report is just science fiction.

what is the proper equipment? examples

 

[12vDC]

.

 

[Warpspeed]

You were asking about a battery capacity / load tester.
No way to do that without doing a full actual timed discharge.

Voltmeter, amp meter and an adjustable load. plus a clock.
And maybe a lot of patience.

How you go about measuring, depends on the type of battery, size of battery, and discharge time according to the intended battery application.

Testing a small watch battery is going to be very different to testing a very large engine starting battery.
A watch battery might be sized for a one year discharge.
An engine starting battery, cranking amps for one minute.

You need to perform a test that is REALISTIC to get any meaningful result.

And you cannot carry out a battery capacity test in just a few seconds, no matter what kind of battery it is.

 

[hwy17]

Amazon.com

This is a common type of actual capacity tester. Probably not extremely accurate but good enough.

Testing takes probably hours per cell.

 

[Warpspeed]

Testing takes probably hours per cell.

First you need to fully charge up each cell, and that will add extra testing time before beginning each discharge test.
Then you will also need to recharge after each test, to avoid potential cell damage by leaving it in a totally discharged condition for any length of time.

 

[hightecrebel]

I understand I can't get a capacity test done in that short of a time period. I was referring more to form factor/style with a built-in printer. I don't have a clean-room style workshop or even a "clean" workshop. I'll either be doing tests in my cellar or my shed, neither location being somewhere I'd want to leave an open circuit board or expensive tester & laptop. I was hoping for a compact, sealed unit that I could pull the info from without needing something else to read it. Even if I need to supply the load or wires, that's not an issue.

A bit more background on my opportunity: In the process of my day job, I ended up at a client's house where he's swapping out his three 24v 2s6p banks for wall-mount 48v batteries. We got to talking about upgrades to his heating system to work better with his solar, and he mentioned he's not looking forward to disposing of his batteries. They're all six to ten year old 12v/35ah batteries, and he offered them to me for $20 each. I figure even if they're at the 80% mark it's still worth it, but I don't want to go and build a bank or six with wildly varying capacities

 

[Warpspeed]

I understand I can't get a capacity test done in that short of a time period. I was referring more to form factor/style with a built-in printer.

I have never seen or heard of such a self contained instrument.

The practical way to do it is with a programmable constant current load, a programmable under voltage load disconnect, and a dc amp hour meter.
Then just write down the accumulated amp hour figure at the end of the test onto a sticky label.

 

[hightecrebel]

I have never seen or heard of such a self contained instrument.

The practical way to do it is with a programmable constant current load, a programmable under voltage load disconnect, and a dc amp hour meter.
Then just write down the accumulated amp hour figure at the end of the test onto a sticky label.

That's about what I figured. I'd looked and couldn't find one, but was hopeful it was due to my own ignorance of where to look.

I'll probably just rig one of the board types into a case of some kind and write the info in a notebook & on a piece of masking tape on the battery case.

 

[Warpspeed]

Yes, its the printer requirement that will snooker you with the available commercial battery testers.

Also, a seriously powerful high current discharge load can get seriously expensive.
A lot of Chinese stuff (junk) is often rated VERY optimistically and is not always all that accurate....

Under voltage disconnect is easy, many good quality digital voltmeters have programmable alarms.

 

[sunshine_eggo]

IMHO, $20 is way too high.

He turned the burden into your problem and got you to pay him for the privilege.