Battery Help Please

[Ryedan]

All my 18650 cells were free - liberated from the recycling bins in various shops/supermarkets - my thread seeking to gain more knowledge about the large spread in claimed capacities I'd found was relegated to the "Not advisable".

From my POV, salvaged cells have already been run in - if they were prone to going bang/venting with flaming gas, the previous owner would already have found out.

Naturally if I found a lithium pack with evidence of destructive failure, I'd throw it back and keep walking.

Do you know what the cell specifications are? Do you test their condition? If so, how do you do it?

Cells don't need to be run in. The previous owner would only have found out if the batteries were prone to going bang if he had abused them. It's extremely rare to get a bad battery that will burn with no abuse.

 

[Ryedan]

Thanks for all the info
looks like I have some homework to do.
I didn't just start building.
I have been using those same coils with IMR 18650 -3.7V - 1600mah batteries for about a year now.
I just need new batteries cause these dont seem to hold a charge for very long anymore.
I will get an ohm meter now and figure out the amp draw moving forward.

Great. Vape on

 

[ian-field]

Do you know what the cell specifications are? Do you test their condition? If so, how do you do it?

Cells don't need to be run in. The previous owner would only have found out if the batteries were prone to going bang if he had abused them. It's extremely rare to get a bad battery that will burn with no abuse.

My thread that was relegated to "not advisable" was asking for any such information to increase my knowledge.

The first pack I salvaged claimed to be 5.2Ah, the cells easily run my e-cig for a whole day, and well into the next if I forget to rotate them in the morning.

My test and measurement bench doesn't quite run to battery internal resistance measuring kit, but all you need to know is if the cell will run an e-cig - and if so, for how long.

One of my cells has been abuse tested - the ego connectors can be prone to shorting, which tends to weld the switch contacts. The cell got pretty warm by the time I realised what was happening and unscrewed the connector.

This may be why Liberty Flights have dropped the ego from their range of DIY parts - AFAIK they still carry the 510 connectors, and this is what I'm converting back to as the ego ones fail.

 

[beckdg]

oy vey

dumpster diving for reclaimed cells? sheesh! talk about not advisable on a sub-o build.

Goochman. check these out... Ohm Meters

 

[Ryedan]

My thread that was relegated to "not advisable" was asking for any such information to increase my knowledge.

The first pack I salvaged claimed to be 5.2Ah, the cells easily run my e-cig for a whole day, and well into the next if I forget to rotate them in the morning.

My test and measurement bench doesn't quite run to battery internal resistance measuring kit, but all you need to know is if the cell will run an e-cig - and if so, for how long.

One of my cells has been abuse tested - the ego connectors can be prone to shorting, which tends to weld the switch contacts. The cell got pretty warm by the time I realised what was happening and unscrewed the connector.

This may be why Liberty Flights have dropped the ego from their range of DIY parts - AFAIK they still carry the 510 connectors, and this is what I'm converting back to as the ego ones fail.

From that thread that got moved:

As a qualified electronics engineer - I take exception to being lectured at by people who clearly haven't got the faintest idea!

I know a few electrical engineers and they all either understand this stuff, or if they don't they immediately get it when I explain it to them. If you're an electronics engineer (is that different than electrical engineering?) why aren't you getting it when people explain the issues and why can't you calculate the battery internal resistance using a DMM and Ohm's law?

What's up man? We are all here to help, but you have to be open to being helped

 

[ian-field]

From that thread that got moved:



I know a few electrical engineers and they all either understand this stuff, or if they don't they immediately get it when I explain it to them. If you're an electronics engineer (is that different than electrical engineering?) why aren't you getting it when people explain the issues and why can't you calculate the battery internal resistance using a DMM and Ohm's law?

You need a little bit more than a DMM and Ohm's law - you have to measure the drop in terminal voltage with at least 2 controlled current loads and calculate the internal resistance from the difference between the 2 volt sags.

With an e-cig as the load; it either works or it doesn't - then you find out how long for.

 

[tae111]

Get a Ohm meter. Then buy imren 2600 mah 38 amp batteries. I also use the Nitecore chargers they work great. I have a collection of around 25 batteries including some real Sony vtc5's and the imren batteries work better than all of them.