You might have a misunderstanding about battery capacity when it comes to different units. Most of the time, in mobile phones, power banks, mobile batteries mostly defined by mAh (milliamp-hours). For the Microsoft Surface family, it might have been noticed that the battery capacity is defined as mWh (milliwatts-hours).
In this tip, we will guide you on how to convert from mWh to mAh and vice-versa.
Table of contents
1Surface Battery Capacity
Here is the list of the battery capacity of all Microsoft Surface is measured of both Wh and mAh:
| Surface Model | Watt Hours | Milliampere Hour, Volts | Est. Battery Life |
|---|---|---|---|
| Surface | |||
| Surface RT | 31.5 Wh | 4,257 mAh, 7.4 V | 8 hours |
| Surface Power Cover | 30.0 Wh | 4,054 mAh, 7.4 V | - |
| Surface 2 | 31.5 Wh | 4,257 mAh, 7.4 V | 10 hours |
| Surface 3 | 27.5 Wh | 7,270 mAh, 3.78 V | 10 hours |
| Surface Go | 26.12 Wh | 3,411 mAh, 7.66V | 9 hours |
| Surface Go 2 | 26.81 Wh | 3500 mAh, 7.66V | 10 hours |
| Surface Go 3 | 26.81 Wh | 3500 mAh, 7.66V | 11 hours |
| Surface Pro | |||
| Surface Pro | 42.0 Wh | 5,676 mAh, 7.4 V | - |
| Surface Pro 2 | 42.0 Wh | 5,676 mAh, 7.4 V | - |
| Surface Pro 3 | 42.2 Wh | 5,547 mAh, 7.6 V | 9 hours |
| Surface Pro 4 | 38.2 Wh | 5,087 mAh, 7.5 V | 9 hours |
| Surface Pro 5 | 45.0 Wh | 5,940 mAh, 7.57 V | 13.5 hours |
| Surface Pro 6 | 45.0 Wh | 5,940 mAh, 7.57 V | 13.5 hours |
| Surface Pro 7 | 43.2 Wh | 5,702 mAh, 7.57 V | 10.5 hours |
| Surface Pro 7+ | 50.4 Wh | 6,657 mAh, 7.57 V | 15 hours |
| Surface Pro 8 | 50.2 Wh | - | 16 hours |
| Surface Pro 9 | 46.5 Wh | - | 15.5 hours |
| Surface Pro 9 5G | 46.5 Wh | - | 19 hours |
| Surface Pro X | |||
| Surface Pro X | 38.2 Wh | 5,039 mAh, 7.58 V | 13 hours |
| Surface Laptop | |||
| Surface Laptop | 45.2 Wh | 5,970 mAh, 7.57 V | 14.5 hours |
| Surface Laptop 2 | 45.2 Wh | 5,970 mAh, 7.57 V | 14.5 hours |
| Surface Laptop 3 13” | 45.8 Wh | 6,041 mAh, 7.58 V | 11.5 hours |
| Surface Laptop 3 15” | 45.8 Wh | 6,041 mAh, 7.58 V | 11.5 hours |
| Surface Laptop 4 13” | 45.8 Wh | 6,041 mAh, 7.58 V | 19 hours (AMD) 17 hours (Intel) |
| Surface Laptop 4 15” | 45.8 Wh | 6,041 mAh, 7.58 V | 17.5 hours (AMD) 16.5 hours (Intel) |
| Surface Laptop 5 13” | 45.8 Wh | 6,041 mAh, 7.58 V | 18 hours |
| Surface Laptop 5 15” | 45.8 Wh | 6,041 mAh, 7.58 V | 17 hours |
| Surface Laptop Go | |||
| Surface Laptop Go | 39.7 Wh | 5,235 mAh, 7.58 V | 13 hours |
| Surface Laptop Go2 | 41.0 Wh | - | 13 hours |
| Surface Laptop SE | |||
| Surface Laptop SE | 35 Wh | 4,613 mAh, 7.6 V | 16 hours |
| Surface Laptop Studio | |||
| Surface Laptop Studio | 56.3 Wh | - | 19 hours (i5) 18 hours (i7) |
| Surface Book | |||
| Surface Book | 69.0 Wh | 9,187 mAh, 7.5 V | 12 hours |
| — clipboard | 18.0 Wh | 2,387 mAh, 7.5 V | 3 hours |
| — base | 51.0 Wh | 6,800 mAh, 7.5 V | 9 hours |
| SB with Performance Base | 81.0 Wh | 10,787 mAh, 7.5 V | 16 hours |
| — clipboard | 18.0 Wh | 2,387 mAh, 7.5 V | 3 hours |
| — base | 63.0 Wh | 8,400 mAh, 7.5 V | 13 hours |
| Surface Book 2 13" i5 | 69.0 Wh | 9,187 mAh, 7.5 V | 17 hours |
| — clipboard | 18.0 Wh | 2,387 mAh, 7.5 V | 5 hours |
| — base | 51.0 Wh | 6,800 mAh, 7.5 V | 12 hours |
| Surface Book 2 13" i7 | 75.3 Wh | 10,027 mAh, 7.5 V | 17 hours |
| — clipboard | 18.0 Wh | 2,387 mAh, 7.5 V | 5 hours |
| — base | 57.3 Wh | 7,640 mAh, 7.5 V | 12 hours |
| Surface Book 2 15" | 90.0 Wh | 12,000 mAh, 7.5 V | 17 hours |
| — clipboard | 23.0 Wh | 3,066 mAh, 7.5 V | 5 hours |
| — base | 67.0 Wh | 8,933 mAh, 7.5 V | 12 hours |
| Surface Book 3 13" i5 | 69.0 Wh | 9,187 mAh, 7.5 V | 15.5 hours |
| Surface Book 3 13" i7 | 75.3 Wh | 10,027 mAh, 7.5 V | 15.5 hours |
| Surface Book 3 15" | 90.0 Wh | 12,000 mAh, 7.5 V | 17.5 hours |
2How to Convert mWh to mAh?
In order to convert from mWh (milliwatt-hours) to mAh (milliamp-hours), we have a formula as below:
(mAh) = (mWh) / (V)
Example: Surface Pro 3 has a battery capacity of 42 Wh or 42,000 mWh has battery capacity in mAh as below:
42,000 mWh / 7.5 V = 5,600 mAh
So, the Surface Pro 3 has a battery capacity of 5,600 mAh.
You can also use the calculator below to help you convert from Wh to mAh or vice versa.
More Resources
- Ultimate tips to max out your Surface Battery Life
- Best external battery chargers for Microsoft Surface
- Best Car Chargers for Microsoft Surface
COMMENTS
Let us know what you think!
We appreciate hearing your thoughts, questions, and ideas about “Microsoft Surface battery capacity – a complete list”.
Can you update this with the new Surface Pro stat?
Hi Alsonot, we’ve updated the stat of new Surface Pro. You can have a look now!
huh. so does this mean we should expect similar battery performance from the surface laptop as we do the surface pro?
Hi carlosatUCLA, you are right! However, Surface Laptop will last a bit longer because of it’s less power Core i5-7200U and lower screen resolution 2256 x 1504 (201 PPI), 3.4M Pixels while Surface Pro (2017) has Core i5-7300U and higher resolution 2736 x 1824 (267 PPI), 5M Pixels.
For more information check out here: https://surfacetip.com/surface-pro-2017-vs-surface-laptop/
Can you do it Microsoft surface laptop go.
I believe it looks like there are two 7.5V batteries in series. As the power supply e.g. surface book P/S below
65 Watt P/S:
DC output: 15V@4amps (60 watts) + 5V@1amp
Model: 1706
Are the batteries in series i.e. base and clipboard? Is that why 15V is required?
Or does the base contain two 7.5V batteries and similarly the clipboard contains two 7.5V batteries?
I generally understand that the charging voltage must be higher than the battery voltage to charge the battery. However … double would be excessive and possibly cause the battery damage??
CAN ANY ONE EXPLAIN TO ME WHY THE ESTIMATED RUN TIME OF MY SB2 BASE PART IS ONLY 2:31 ???
As you can see on the screenshot, it’s calculated base on charge rate (Full Charge/Current Discharge rate = 50,340 mWh / 21778 mW =2.31 Hour). The charge rate of the base is 21.7W while on the clipboard is only 2.9W.
And one more thing that you need to know, on Surface Book, Microsoft use an algorithm that will discharge battery in base first, so it can guarantee that the clipboard stay full charge when you need to detach.
My battery – Microsoft Surface Book – died suddenly. The tablett battery is still working, but the other one no, so I cannot use the device as laptop. For the price of this laptop, the death of the battery is a shame! Shame on Microsoft! ???
How do I replace the battery in my Surface RT?
Hello,
Im just a new user for this device (surface book 2) about 1,5 months and would you please explain further how does this device work for 17 hours as described above ? my own experience during this time in fact this device has never reached to 17 hours, in most of the time it only last for about 4-5 hours only and one big issue is the battery also drain fast even it has been shut down properly, what is causing this happened and how to solve this ?
Hello! i am a bit cinfused as i just took apart my surface book 2 to replace the battery and what I found was a 57,3Wh 11,36V battery. This Version is not listed in the table and I was wondering if it is original. I habe the 13,5 inch Performance Model woth the NVidia GTX 1050.
Julian
50.0 watt-hours Surface Pro 7 Plus (2021-01).
46.5 watt-hours Surface Pro 7, according to TheVerge, xda-developers, and other sources.
Surface Laptop 3
6000 mha and only 11 Hours haha
I have Surface Pro 2 dismantled due to battery bubble up. I going to replace it with any universal battery available nearby, so I wonder whether 42Wh and 5,676 mAh, 7.4 V is for each piece of battery? or that spec is the combined of both pieces connected in Parallel?
Estoy buscando un cargador para el coche compatible con surface pro 8, existe?
Gracias de antemano
hi I have surface book 3 15 i7 1660ti I wonder can i charge it with a 65 watt power bank and another question that the adaptor was 102 watts while the microsoft says 127 does that harm the battery?
Hi Sajjad,
Thanks for your questions!
1. Yes, you can use a lower-wattage charger to charge your Surface Book 3, as long as the charger is a Surface charger or a PD (Power Delivery) USB-C charger. The 65-watt power bank is powerful enough to charge the laptop while handling light to medium workloads.
2. Using a lower-wattage charger won’t harm the battery. The thing that negatively affects your battery lifespan is overheating and keeping the laptop at full charge permanently without enabling the battery limit feature. You can learn more about how to turn the feature on here: https://surfacetip.com/enable-battery-limit-feature-on-surface-devices/
I hope it helps!
Thanks,