9-cell battery for X220: 0A36307 vs 0A36283

I need to buy a new 9-cell battery for my X220. I'm a bit confused, because there are two compatible 9-cell batteries:

- The 0A36283 is called "29++"
- The 0A36307 is called "44++"

Both have have 94 WH, both have 9-cells and both are compatible with the X220. Could someone please explain to me what the difference is, and what the "29++" and the "44++" stand for?

 

29++ - has no authentication chip, and can only be used in X220
44++ - comes standard with the authentication chip, an be used in X220 and X230

So, there is no real difference for you as you own a X220 and not a X230.

 

Thanks a lot. What is the authentication chip for? To check whether the battery is genuine?

 

Yes. You can´t use 3rd party batteries in the X230, because they lack this authentication chip. Lenovo did this because 3rd party batteries can be very dangerous (there is a small chance that they can explode).

 

The primary reason was the X230's RapidCharge feature, which 3rd party batteries may not support. But let's be honest here, it's also because selling batteries is quite profitable if you lock out 3rd party options

 

Yes, of course, both are valid reasons too.

But I don´t think the X230 has the option for rapid-charge, only the X230 Tablet have this option, and only in some countries.

 

Ah, my mistake then, thanks for the correction. In that case, it's pretty much solely a for-profit decision.

 

I think the 4 cell does rapid charge.

It's a profit thing because selling batteries way above what they are worth is a profitable activity. It also allows you to lock out old models even if the battery is physically compatible if you so wish.

 

greedy s.

 

I don't see how it is greed. IF you were an OEM, wouldn't you want to protect your product? HP and Lenovo are infamous for whitelisting WLAN cards, do we cry and moan about that too? No, you learn to deal with it and move on. You know how many cheapo knock off batteries come from the other side of the planet, not knowing what condition they were made, and what potentially could be inside? And yes, batteries CAN explode and can pose a risk, hence USPS banned Li-On batteries on international shipments.

Whitelisting RAM or a hard drive could potentially be an outrage, but even Apple does this on their iMac's, if you buy a different hard drive, you have to order a proprietary cable from Apple to plug into the drive (as least with last generation iMac's).

 

^I agree with what your saying but users do know they take the risk by going with aftermarket batteries.

If I was an OEM, I would be fine with my product failing on a customer because they will get a replacement and it will likely be a thinkpad.