Charging issue

[Jake Smoke]

When my batteries are fully charged, they read out about 4.22V. They're relatively new Fogstar batteries, 3.7V 3500mah, 10-20A.
However, when I take them off the charger and test them instantly, they read out at 4.26V.

I've been reading that if a charger is charging over 4.2V, that the charger is faulty and should not be used. This is relatively new (about 2 months old), and admittedly cheap equipment.

I never knew the charge before because I only now got a V meter in my spanking new Coil Master V3 toolkit.

Should I return the charger and ask for a new one or is this an acceptable over-charge?

 

[Mooch]

What are you using to test them when they are out of the charger?
4.26V is at the high end of barely acceptable but not dangerous.

 

[DaveP]

When my batteries are fully charged, they read out about 4.22V. They're relatively new Fogstar batteries, 3.7V 3500mah, 10-20A.
However, when I take them off the charger and test them instantly, they read out at 4.26V.

I've been reading that if a charger is charging over 4.2V, that the charger is faulty and should not be used. This is relatively new (about 2 months old), and admittedly cheap equipment.

I never knew the charge before because I only now got a V meter in my spanking new Coil Master V3 toolkit.

Should I return the charger and ask for a new one or is this an acceptable over-charge?

The 3.7v rating of the battery your listed is the nominal voltage of a lithium cell. 4.1v to 4.2v is the fully charged voltage level for a lithium cell depending on the charger. As Mooch said your voltmeter may not be accurately calibrated.

Fogstar is self proclaimed to be a good battery by Fogstar UK. They are obviously rebranded batteries.
Fogstar - The UK's #1 trusted source of 18650 Batteries

You didn't say what brand and model charger you have. That, and we all like Sony, Samsung, and LG batteries for our top performing models, although there are many more great batteries you could buy.

Efest LUC 4 and XTAR VC4 are good chargers that you can trust. They also make 2 bay models for a little less money if you want to save a buck or two.

 

[Jake Smoke]

What are you using to test them when they are out of the charger?
4.26V is at the high end of barely acceptable but not dangerous.

I don't have any special volt meters so I'm using the ohm meter from my coil master v3 set.

 

[Jake Smoke]

The 3.7v rating of the battery your listed is the nominal voltage of a lithium cell. 4.1v to 4.2v is the fully charged voltage level for a lithium cell depending on the charger. As Mooch said your voltmeter may not be accurately calibrated.

Fogstar is self proclaimed to be a good battery by Fogstar UK. They are obviously rebranded batteries.
Fogstar - The UK's #1 trusted source of 18650 Batteries

You didn't say what brand and model charger you have. That, and we all like Sony, Samsung, and LG batteries for our top performing models, although there are many more great batteries you could buy.

Efest LUC 4 and XTAR VC4 are good chargers that you can trust. They also make 2 bay models for a little less money if you want to save a buck or two.

Like I said, I'm using a cheap charger. I'm about to move to a different country (220V to 110V) so I opted for a USB charger. This is the model I have: YaPeach Trustfire TR-16. I actually have 2 of them, one of them charges up to 4.14V which seems correct, the other goes to 4.26V (and also charges a tiny bit faster).

I recently bought a Reuleaux RX2/3 and no, I don't use the Fogstar batteries on this device. I bought a set of 3 LG HG2 and 3 Sony 25r batteries for it. I will try the occasional 200W hits on my TFV8 but I really cannot take the heat in my throat and lungs. Most times I am using it more around 90-100W. I know that you need top notch batteries to hit the high wattages and having those possibly explosive devices so close to my face is a bit scary.
The Fogstar 3500mah batteries were purchased for a Vaporesso Target Pro and I usually don't go any higher than 35W on those. They're rated for 10A continuous and 20A pulse.

 

[DaveP]

Like I said, I'm using a cheap charger. I'm about to move to a different country (220V to 110V) so I opted for a USB charger. This is the model I have: YaPeach Trustfire TR-16. I actually have 2 of them, one of them charges up to 4.14V which seems correct, the other goes to 4.26V (and also charges a tiny bit faster).

I recently bought a Reuleaux RX2/3 and no, I don't use the Fogstar batteries on this device. I bought a set of 3 LG HG2 and 3 Sony 25r batteries for it. I will try the occasional 200W hits on my TFV8 but I really cannot take the heat in my throat and lungs. Most times I am using it more around 90-100W. I know that you need top notch batteries to hit the high wattages and having those possibly explosive devices so close to my face is a bit scary.
The Fogstar 3500mah batteries were purchased for a Vaporesso Target Pro and I usually don't go any higher than 35W on those. They're rated for 10A continuous and 20A pulse.

I wouldn't worry about the one that charges to 4.14. The 4.26v charge level from the other charger is on the high side. If you can't tell a difference in battery case warmth between the two after charging you are probably alright. I have read forum posts on Candlepower and AR15 forums that talked about chargers that would trip the over current protection at 4.26V and shut down, so there must be a valid reason not to go over 4.2V.

The Xtar VC4 or VC2 chargers are also USB chargers and they are considered to be accurate. You just need a USB wallwart for your country with at least one 2A output. If it doesn't provide 2A to the charger you won't get 1A charging on multiple ports. The VC series will charge two batteries at 1A each with a 2A USB supply.

The Efest LUC 4 will charge 4 18650's at 1A each simultaneously, but it plugs directly into a wall outlet.

 

[Jake Smoke]

I wouldn't worry about the one that charges to 4.14. The 4.26v charge level from the other charger is on the high side. If you can't tell a difference in battery case warmth between the two after charging you are probably alright. I have read forum posts on Candlepower and AR15 forums that talked about chargers that would trip the over current protection at 4.26V and shut down, so there must be a valid reason not to go over 4.2V.

The Xtar VC4 or VC2 chargers are also USB chargers and they are considered to be accurate. You just need a USB wallwart for your country with at least one 2A output. If it doesn't provide 2A to the charger you won't get 1A charging on multiple ports. The VC series will charge two batteries at 1A each with a 2A USB supply.

The Efest LUC 4 will charge 4 18650's at 1A each simultaneously, but it plugs directly into a wall outlet.

None of the batteries get "warm" after charging. I guess they get warmer the faster you charge them but with a USB charger it does take quite some time to have them charged. I usually have the chargers right in front of me on my desk and as soon as the fully charged indicator comes on, I notice, take them out and put them in their protective boxes so I know they've not been sitting there and cool down. Both chargers charge all batteries at pretty much room temperature.

 

[Jake Smoke]

And after leaving the charged batteries for a couple hours, the overcharge seems to go away and they'll measure up to about 4.22V. So I'm not sure if this is some misreading because they just came out of the charger and the batteries are a little "excited" or something like that?
Like I said, I'm not really good when it comes to electricity, I don't really get how these things work.

 

[DaveP]

And after leaving the charged batteries for a couple hours, the overcharge seems to go away and they'll measure up to about 4.22V. So I'm not sure if this is some misreading because they just came out of the charger and the batteries are a little "excited" or something like that?
Like I said, I'm not really good when it comes to electricity, I don't really get how these things work.

Do some reading here. You'll absorb all you need to know. Search for lithium 18650 and go from there.
www.batteryuniversity.com