Skip to main content

.TT pocketEngineer softDesign

... pocketEngineer software for mobile design

pocketEngineer software  animated gif (free)  email me  buy now  thoughts   
...Ductulator Plus+
...aDuctulator (And)
...aBattMV (And)
...aKitchenExhaust (And)
...tRod Sizer (free)
...pocketPipe Sizer
...aPipeSizer (And)
...multi Pipes PD (And)
...aPocketGas (And)
...rhoAIR (free)
...aRhoAIR (free) (And)
...aPsychroAC (And)
...AirTAB superEZ
...Qcool Check
...aCriticalVel (And)
...aPocketPool (And)
ePF Loop Pdrop
...hydrant pressure drop
...Pumping Mainline
Rethink, Reinvent apps
...CurveFit Tracer
...gas suppression
...CA ring main Pdrop
.TT pocketEngineer softDesign - shaping tomorrow's  design solutions  ...
Dear customers & visitors, as Microsoft is closing down its SharePoint soon, .TT pocketEngineer softDesign is relocating its home to Google site at
 Battery Ventilation Calculation - battMV v6.17 

battery room ventilation to EN 50272 Standards



To take a glance at all pocketEngineer software and OS requirements, click Overview.

For Android OS, see  aBattMV.


 battMV: just point & click design 

Design of battery room ventilation using hydrogen concentration dilution method has been made easier withbattMV program - a small Windows PC program specially designed for engineers & designers.

Aim: creating a mobile design environment (
ShowMe!) for the practising engineers & designers in today's mobile world.

Results: Instant solutions at your fingertips.



- battery room ventilation calculations
- by Hydrogen concentration dilution method in accordance to EN 50272-2 & EN 50272-3 Standards
- "Select  & Click" with built-in data like Igas, battery rated capacity, room volume calculator, etc 

- louvre sizer
- save results for printing

- in SI & IP units


 Design Principles . . .

The battery room ventilation is calculated in accordance to EN 50272-2 & EN 50272-3 Standards. The ventilation flow rate is calculated using the following formula:

Q = v * q * s * n * Igas * Cn / 100

Q = ventilation air flow (CMH)
v = necessary hydrogen dilution factor (depends on % of air-hydrogen mixture)
q = hydrogen release rate, typically=0.00042 m3/Ah
s = safety factor, generally=5 for building projects
n = number of cells
Igas = current producing gas during charging (A/100Ah)
Cn = capacity of a battery (Ah). Note: This refers to rated ampere-hour capacity of lead acid or NiCd cell of the battery.










How to calculate ventilation requirements for a battery room?

 Calculation Example: instant results 

Instant results at your fingertips on-the-move with  battMV program. 

Example (in English units)
A battery room (40 ft x 30 ft x 15 ft high) contains 10 batteries. Each battery has 18 cells. The rated capacity of the battery is 850 Ah. Boost charging method is employed for charging of battery. The hydrogen concentration in the room shall be kept below 1%. Find the hydrogen concentration in the room, and ventilation rate required.
Ignore the volume occupied by the battery.

Instant results
Nos. of cell per battery = 18
Rated capacity of battery = 850 Ah

Nos. of Battery = 10
Charging current, Igas = 0.02 A/Ah
H2 release rate = 0.01474 ft3/h

Hydrogen produced = 45.1044 ft3/h

Nett Room Vol = 18000 ft3
% of Hydrogen gas in room after 1 hour without ventilation = 0.2506%
Allowable Hydrogen = 1%
Safety factor =5
Airflow required = 372.11CFM
Room Air-change/Hr = 1.24


The following duct sizing result is calculated using  Ductulator Plus   program (to be purchased separately):


Retangular Duct sizing......
Friction loss rate =0.1 in.wc/100'
Duct roughness, e =0.0003 ft
Air volume =372.11 CFM
Duct height =6 in
Duct width =13 in

Duct velocity =697.94 FPM

(1) Flow area, A = 0.533 sq.ft
(2) Hydraulic dia, Dh = 8.2 in
(3) Reynolds nos, Re = 48,851
(4) Relative roughness, e/Dh = 0.000441
(5) Friction factor, ff = 0.022471
(friction factor solved by ColeBrook equation)




Price: USD 7.90 only


Download now:


product detail  


OS requirements: Windows.


For Android phone OS, see 


Accept: credit card payment with PayPal


1) Pay & instant Download via Sellfy service:


>> Buy Now & Download



2) Pay & instant Download via Click2Sell service:





Note: check your email / junk mail after making payment.

 to EN 50272 Standards

in SI & IP units


 view battMV explained



 Igas selection




Louvre Sizer



Room Volume Calculator