600W battery charger design

[reggie]

Hi all,


My battery charging knowledge is limited, but I know a bit about SMPSU
design.

I was wondering what topologies and silicon could be used to deliver
substantial powers used to charge a 300Ah 24V lead acid battery bank
(employing three stage charge curve like :-
https://www.electroparts.com.au/images/bc_chart_large.jpg).
​

I have thought:-


1) Front end boost circuit, to give unity PFC and constant voltage
over wide input voltage range
​

1.1) But have read that due to high peak currents can be unusable at
powers above 150w (onsemmi switch mode PSU reference manual SMPSRM/D
rev 3B July 2002 page 9)
​

1.2) Should I parallel up boost circuit or go to duel-phase for higher
powers (not just components entire circuit)


1.3) What effect would the input frequency swing have on the boost
circuit?
​

2) Probably a full isolated bridge with synchronous rectification.


3) what effect does the three stage charge cycle have on output
voltage and current the PSU supplies (told you I don't know much about
battery charging)?
​

4) Are there any good guides for designing lead acid battery chargers
within this power range?


5) any application guides / circuits on the net for this type of
application?
​

specification:

Input voltage: 90 - 260 VAC RMS
Input frequency: 40 - 100 Hz
Nominal output power: 600 W +/- 5%
Nominal output current: 25 A
Rated battery voltage: 24 VDC
Operating amb. temperature: -25ºC to +40ºC
Efficiency: >85%
Cooling: forced air and none forced air
Package:187mm x 116mm x 50mm
​

 

[Hero999]

I couldn't access your picture, please attach it.

To float charge the battery, the output voltage needs to be 27.6V.

Just make sure the SMPs is current limited.

 

[reggie]

sorry about the jpg. The charging cycle chart can be seen on this page:

**broken link removed**

 

[carmusic]

if you don't want to build one i would use this batteyr charger
**broken link removed**

 

[reggie]

Thanks for the link carmusic, but i do want to design one.
Any ideas?