Samsung INR18650-15M and INR18650-13Q cells

[ic3wall]

Hi everyone,

I'm about to start building packs with samsung INR18650-15M and INR18650-13Q cells coming from Milwaukee tools and the only piece of information I have for now is this: http://www.samsungsdi.com/battery/cylindrical-rechargeable-battery.jsp

One is 1.5Ah and the other is 1.3Ah... other than that I don't know much. While taking apart the used packs, I realized the problem was always the same, 2 bads cells out of 10.

I was wondering if other people had some experience with these cells ?? Does anyone know the max discharge current ? What would be a safe discharge current?

Thank you

 

[SlyCayer]

Does anyone know the max discharge current ? What would be a safe discharge current?

Did you take these out of Red-Lithium packs?

 

[cassschr1]

IIRC there 15and 13 max discharge BUT the bad is a low current charge. like.5 So you have long charge times.

 

[ic3wall]

Does anyone know the max discharge current ? What would be a safe discharge current?

Did you take these out of Red-Lithium packs?

yes

IIRC there 15and 13 max discharge BUT the bad is a low current charge. like.5 So you have long charge times.

So they are 10C ?

 

[ic3wall]

and what about charging... Can I charge them in parallel by setting the voltage to 4.1-4.2 and simply limiting the current to 0.5A ?

Or a BMS would be necessary (Please say no hehe )?

 

[cassschr1]

I believe thats correct....10c. for charging : example, say 15s8p would be 63v, 4amp

 

[999zip999]

15s- 62v is a great ebike battery.

 

[SamTexas]

... samsung INR18650-15M and INR18650-13Q cells coming from Milwaukee tools...

I have no experience with the Samsung cells you mentioned above. But if they are from tools' battery packs they are most likely Lithium-Manganese types. I do have experience with the following Lithium Manganese 18650 cells:

From 18V Ryobi pack (5s2p): LS IMR-18650BB, light blue, China
From Milwaukee 16wh pack (3s1p): Moli IMR-18650E, light tan, Canada

The specs for the Moli IMR-18650E cells are:
1.4Ah
32 mOhm
Discharge to 2.5V
Max discharge rate 14.3C (20/1.4)
Max charge rate 4.6C (6.5/1.4)

I have no need for such high discharge rate (14.3), so I only tested them at 4C. They perform well at 4C, the cells do get warm but never hot.
I only have a 1.5A charger, so that what I was charging them at.

Many people on this board will tell you that Lithium-Manganese (aka spinel) will self balance when charged in series. My real life experience says otherwise. I deliberately created an unbalanced 3s1p pack (3.7V, 3.8V and 3.9V) and bulk charged them overnight using a 12.6V charger (4.2 * 3 = 12.6). This was what I got in the morning: 4.08V, 4.18V and 4.34V. No, no fire, no explosion.

I have no plan to use these cells on my bicycle because of their low energy density. But if I did, I would either use a balance charger or a BMS.

 

[ic3wall]

... samsung INR18650-15M and INR18650-13Q cells coming from Milwaukee tools...

I have no experience with the Samsung cells you mentioned above. But if they are from tools' battery packs they are most likely Lithium-Manganese types. I do have experience with the following Lithium Manganese 18650 cells:

From 18V Ryobi pack (5s2p): LS IMR-18650BB, light blue, China
From Milwaukee 16wh pack (3s1p): Moli IMR-18650E, light tan, Canada

The specs for the Moli IMR-18650E cells are:
1.4Ah
32 mOhm
Discharge to 2.5V
Max discharge rate 14.3C (20/1.4)
Max charge rate 4.6C (6.5/1.4)

I have no need for such high discharge rate (14.3), so I only tested them at 4C. They perform well at 4C, the cells do get warm but never hot.
I only have a 1.5A charger, so that what I was charging them at.

Many people on this board will tell you that Lithium-Manganese (aka spinel) will self balance when charged in series. My real life experience says otherwise. I deliberately created an unbalanced 3s1p pack (3.7V, 3.8V and 3.9V) and bulk charged them overnight using a 12.6V charger (4.2 * 3 = 12.6). This was what I got in the morning: 4.08V, 4.18V and 4.34V. No, no fire, no explosion.

I have no plan to use these cells on my bicycle because of their low energy density. But if I did, I would either use a balance charger or a BMS.

Thank you very much for this complete answer! I also have a considerable amount of these Moli IMR-18650E, light tan, Canada and I was wondering if it would be a good idea to make packs with them because I noticed they had quite a high internal resistance (100-250miliohms) compared to INR18650-13Q (which are 15-75miliohms).

I'm also glad to hear of your experience about charging these cells in series... my plan was to make a 12s6p with INR18650-13Q and charge each parallel group individually ? It would also allow me to do some monitoring!

I might give a try at charging 3 parallel strings in series (when dead, voltage=3.0V*3 =9V) with a 12V 3.5A charger and see what happens... comments?

Finally, with a 12s6p configuration, which would give me approximately 48V and 7.3Ah when fully charged, would it be safe to run the pack at 3-5C continuously considering a max discharge rate of 10C ?

Thanks

 

[SamTexas]

Thanks

You're welcome.
I did not pay close attention to the internal resistance while I was testing them. But your 100-250 mOhms figure is quite far from the 32 mOhms specified by Moli. Since the Molis I tested had no problem at all at 4C (complete discharge in 15 mins), I would not hesitate to use them for Ebike application. The reason I chose not to was because I had plenty of 18650 Lithium Cobalt (aka laptop) cells that had 70% more energy, albeit at a much lower discharge rate.

I'm also glad to hear of your experience about charging these cells in series... my plan was to make a 12s6p with INR18650-13Q and charge each parallel group individually ? It would also allow me to do some monitoring!

If you charge each parallel group (pg) individually with the proper charger (4.20V) there is no need to monitor. Nothing will get out of balance. But charging each pg individually gets quite annoying if you have to do it on a daily basis, unless you have 12 individual chargers and combine them into a single charger with a 13 pin connector. That's how I built my worry free charger. It will charge any pack no matter how unbalanced the pgs are.

I might give a try at charging 3 parallel strings in series (when dead, voltage=3.0V*3 =9V) with a 12V 3.5A charger and see what happens... comments?

If you start with balanced pack, you would most likely end up with a balanced pack even with bulk charging. This will most likely happen with any lithium chemistry. What you want is to prove to yourself whether bulk charging can balance a severely unbalanced pack.

Finally, with a 12s6p configuration, which would give me approximately 48V and 7.3Ah when fully charged, would it be safe to run the pack at 3-5C continuously considering a max discharge rate of 10C ?

I don't know about 5c, but I did test them at 4c and was able to successfully and completely discharge them in 15 mins. So I can only say up to 4c. BTW the specs for the Molis says 14.3c discharge, not 10c. But as usual, I suspect that the specs is optimistic.