Author Topic: Bratt in 24 volts  (Read 178 times)

Highflyer

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Bratt in 24 volts
« on: August 11, 2018, 09:57:33 AM »
All,
I have used my Bratt for 12 volts before, but now I have a 24 volt application.  So, as I read the manual I would like a few things confirmed before I close the breakers. 

How much power does the Bratt use?  I only need to charge using one or two amps for this project But I don't know how much to add for the Bratt's needs and I can't find its draw in the manual.

Secondly, can someone explain the benefits of Sealed profile #1 and #2 please?  Why do I want one over the other?  I will be using new sealed LA batteries for the storage.

Third question, S1-8 turns the PWM off (in the on position), why would I want to do that, isn't the PWM charger what the Bratt does?  Why would I want to turn that off?

The project is going to power a tracker for a larger array.  It needs 24 DC to run and I don't want to send power back out to the array, so I 'll use two small 12 volt panels to keep a battery set charged and it will run the tracking system.

Thanks for the help.
Brian

The one thing is the one thing

Vic

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Re: Bratt in 24 volts
« Reply #1 on: August 12, 2018, 05:12:14 PM »
Hi Brian,

The Tare of the Brat has been discussed here.  (search =   '   Brat Tare    ')

Found several references to it:

 1.  zoneblue  stated that one Brat had a Tare of 14 mA at 26V.
 2.  And before there were production Brats (IIRC),   that the target was less than 10 mA,  with no voltage specified.

On Sealed 1, & 2,   as you see,    there are slightly different Absorb and Float voltages,   depending on the requirements of the batteries,   etc.  Look at the manufacturer charge specs to see which Sealed selection works best for the exact battery that you will be using.

It is not uncommon for PWM CCs to have a more RFI silent mode,   for those who need lower Emission levels.

FWIW,   I have NO personal experience with the Brat,   and cannot measure its Tare.   Good Luck with the project,   Vic
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!

Highflyer

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Re: Bratt in 24 volts
« Reply #2 on: August 13, 2018, 10:33:57 PM »
Thanks Vic.

A 14mA Tare is very easy to work with. 

As for the two standard voltages, thanks, that is what I figured, and it seems like they are very common numbers.

I have no RF concerns, so I'll leaver the PWM portion running for this application.

Again,

Thanks for the help.
Brian

The one thing is the one thing