DC supply / charger

[itsmoked]

We have removed a large wheel/axle driven generator that provided 150A into a truly monstrous battery bank,(several tons).

For historic purposes we don't want to change out all the 24V systems - we want to continue to use them. This means we need about 70A @ 24VDC.

We will have a modest bank of 6V or 12V LA deep cycle batteries in series.

I need a charger that will not toast them but can also provide up to 70A continuously. It can be 240V single OR three phase.

Anyone have a make/model suggestion?

I am also considering just a straight 70A+ power supply set to the bank's float voltage. There is some small issue with the fact that the float voltage is tied to the ambient temperature and this car can run ambients from -20F to 140F.
Thoughts on that would be appreciated too.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[slavag]

Hi Keith.
Please see attached

http://www.benning.de/19_Syst._300012000W.3.1.2.566.html

Best Regards.
Slava

 

[DanEE]

While we haven't used the particular series of Peco II chargers linked to below, they might be a match for what you need. This particular unit is modular in 50amp increments at 24volts.

http://www.peco2.com/products/pdf/mcs1800_cutsheet.pdf

We have sold and installed a many Peco II 5067 DC panels, the 827E series inverters and been very pleased with their quality and performance. The particular charger we use (SM50F48 series) doesn't show up on their web page for some reason.. Those are 48 volt units anyway....

http://home.4x4wire.com/deddleman/

 

[DanEE]

(arghhh! I hate that this forum won't allow posts to be edited posting)

some additional on your temp range......

I sure you know the temp range you specify is horrible for most any battery.. I would definitely go with a temperature compensated charger, otherwise you risk a thermal runaway situation on the batteries.. Lead acid wet batteries would be more tolerant, but that extreme temp range needs serious thought..

Will the operational range be from -20 to 140F, or is it only during storage (shutdown situations)? That would at least eliminate some concern about thermal runaway.

Definitely stay away from AGM sealed batteries..they are prone to thermal runaway when ambient gets over 95 degrees F. Had it happen at one of our installations that supposedly was a continuously controlled temperature environment.

http://home.4x4wire.com/deddleman/

 

[itsmoked]

Thanks slavag, and DanEE, for the links.

Stuff is looking pretty pricey..

Those modular units are nice though.

I am now shifting things a bit. It turns out that two hours of emergency lighting is what's required and wouldn't require the 70A by any stretch.

1) I am proposing that they put in a much smaller bank of batteries.

2) Put in a small cut-off multistage charger capable of recharging the batteries over a day.

3) Separate out the minimum required lighting circuits for access to battery power.

4) Purchase or build a 80-100A unregulated DC supply running from the 3-ph mains.

5) Put in a mains powered contactor to isolate the battery bank from the system.

If the mains go dry the contactor drops out hooking the battery bank up to the appropriate light fixtures.

See any problems with this?

It was suggested that the stepped down mains be left as 24V AC since all loads are universal motors and incandescent lights. But the owner thinks the lights look different with AC verse DC running thru them...

Keith Cress
kcress -

http://www.flaminsystems.com

 

[rbulsara]

Keith:

How about a 70A-100A DC power supply and a separate battery charger. Make the best battery selector between the output of the P/S and the batteries using blocking diodes?. Load is served via the P/S normally, and if it loses power, the battery takes over seamlessly. I presume you have a standby power system. This is what we do our critical DC control power systems.

Why look for a charger that is capable of large power supply when you can use standard products? Unless I am missing something.

 

[jraef]

Keith,
Master Control Systems. Their main product line is fire pump controllers, but because they make diesel controllers, they got into the business of battery chargers so now they have a decent line of chargers, mainly of the type that charge multiple forklifts and AGVs in facilities.

http://www.mastercontrols.com/ProdInfo/MBC_Prods_Icon.htm

 

[DanEE]

Thought I'd post a couple of additional possible sources below that are much more affordable..

I've always been impressed with the stuff from Xantrex, but have no direct experience with it.. It appears to be one of the better manufacturers of inverters, chargers, but not at the level and directed at the commercial/industrial/telecommunications market such as the PECO II, and hopefully much more cost effective..

http://www.xantrex.com/

Also Samlex makes some pretty impressive, but affordable hardware.. I do have one of their modular 100amp power supplies running 3 repeaters on the communications platform on a commercial TV tower. Very affordable and good quality..

http://www.samlexamerica.com/

We also used one of the Samlex chargers inside a FERRUPS UPS to replace the internal charger that had failed for a customer that was trying to hold costs down. The OEM charger board was far too expensive as a replacement item..

So check both of these out as a possible source of affordable hardware that might meet your requirements.

http://home.4x4wire.com/deddleman/

 

[alehman]

If this is emergency lighting for a building that must be inspected by the local building authority, the emergency lighting power supply may need to be approved by a nationally recognized testing lab (e.g. U.L.). Probably a good idea anyway.

http://www.chloridesys.com/products/emergencylighting/cpmemergencylighting.asp

http://www.acuitybrandslighting.com...Emergency/Power Systems/Power Systems/EDC.pdf

 

[davidbeach]

alehman, most rail cars that are still mobile are not subject to the local building authority. Could be difficult to define "local".

 

[alehman]

Yes, sorry. "wheel/axle driven generator" should have been a clue I guess.

 

[rbulsara]

I am a bit confused now, so where does this battery charger/power supply will be fed from if the generator is removed??

 

[itsmoked]

A 70kW, Stadco, 240V, 3Ph, diesel, generator.
As mentioned this car is a Historic rail car. circa 1928. So as much as possible is to remain the same. We have to even leave dead electrical lockers intact. However people don't much like just 'surviving' in them so we need things like 20 tons of refrigeration and full electric kitchens, hence a large nearly silent generator that will run whenever the car is occupied.

rbulsara; We are debating the diode verse contactor issue. No clear solution. Diode instant and fast and voltage dropping.

jraef; Those Master chargers sure look sturdy. Seem a little pricey though. 10A ~ $500

DanEE; We will likely just do the Xantrex charger at this point. Oh and your question on temps. Yes that is the operating range for the temps not the storage. Using a Xantrex with a battery temp sensor is probably our best bet as the charger will be inside, in an electrical locker, and the batteries are outside underslung.


Keith Cress
kcress -

http://www.flaminsystems.com