Charging many 80AH batteries, how?

[Ichan]

Hi,

About 100 Lead Acid battery 80AH need to be charged per week, what kind of equipment setup is needed?

-ichan

[Wizpic]

This all depends on your battery voltage and how many you put  in series and parallel,
Say if there 6V 80AH you can put 4 in sereis this gives 24V or 8 which make 48V 80AH then you could add the same then join these parallel with the others this then would either make 24 160AH or 48V 160AH, Plus do you need to bulk charge or float charge.

[gregger2k]

Also--

The charge current, bulk, absorb, and float voltages depend on the battery type.
Sealed lead acid (Gell, AGM) take different charge voltages and will not survive an overcharge.

Checkout the battery faq at http://www.batteryfaq.org/ for all the gory deatils.

What type of batteries do you need to charge?

Greg

[FriskyFerret]

Patco Electronics makes some really good lead-acid chargers. Not cheap.

http://www.patcoelectronics.com/LeadChargers.asp

[Diramo]

Very good re-configurable battery chargers produce Canadian company Delta-Q:
http://www.delta-q.com
Also the other company, from Korea,  makes many kinds of industrial battery chargers, mostly for US and Japan.
http://www.signetsys.com

[Walkura]

I builded chargers for this sort of setup before .
Those were 10 chargers of 12 Volt 20 Ampere ,
but since you have just 80 Ah battery's i would advice a 8 Ampere charger for this .
When i know what battery(s) it is ,i can be more specific .
We build these chargers to customer specification .

[tAhm1D]

One idea could be:
Connect 50 batteries in series, 50 in series, and these 2 in parallel. So you have a bank of 600v(assuming your batteries are 12v each) 160AH. Rectify mains and step it upto about 650v and charge the batteries using ~20A current. So, that's 650x20 = 13kW of power. Use IGBT modules in full-bridge configuration and a number of ferrite cores.
It's achievable, but not easy.
Or you could just have different chargers for different batteries. Say put 10 in series and charge these with a 150v 10A charger and have 10 of these chargers.
Certainly not an easy task.

[Ichan]

The batteries is 12V 80AH, sorry I forgot to point this out.

The story behind:
- A customer had a contract to install 100 outdoor billboard where the electricity is unavailable for 2 years.
- The back light will be LED based, powered by 12V 80AH automotive (truck) battery.
- He's calculation that he need to replace and charge the batteries once a week.
- He is asking me to build the LED back lighting system and finding the solution for battery charging.

But I still not getting the deal for this 

The batteries do not need to be charged all for once a week, it can be scheduled daily (about 15/day), so it should not be so hard. As the contract is for 2 years then the charging method need to be good enough to give them the proper life time.

No problem with the back lighting, still looking for the best solution on charging, and the most important - still waiting for the deal...

-ichan

[sphinx]

i used this idea for a customer that wanted a high ampere battery charger, with manual regulation
schematics are in proteus

regards mike

[Ichan]

Thank you, but how it works?

-ichan

[sphinx]

the transistor is the one that does the work by regulating thruu the diode bridge it lets you control the amount of amps/voltage depending on how much you open it. that makes it quite linear thruu transformer.
but be careful when u control transistor thats primary side and that circuit needs to de isolated from other circuits. circuit might look weird but works good i just used a simple isolated circuit to control current on transistor to be able to control how much power i wanted on output on transformer

regards mike

p.s. look at the transistor as a valve you open and close (0-100%), and then look at circuit

added:
ichan what i call high voltage side is primary side since in most cases its higher voltage compared to secondary side

[Ichan]

Thanks for the explanation, but i think i will not going to control the primary side, high voltage scares me.

For anyone interested I found a schematic of battery charger for 9 of 12V 100AH battery in series from 120V AC outlet, this is from Nuts & Volts magazine June 2009.

For now i am thinking of using modified PC ATX power supply for power source plus uC based charging controller, but then i will need 15 set of them.

Anyone has experience with "Advance Charger" from http://www.seven-segments.com/index.php?action=menucats&id=13? How can it be so simple 

-ichan