looking for a COTS battery power pack with all the trimmings 2

[NuclearNerd]

Hi there

I'm a mech eng, so this is veering outside my expertise. I'm in the process of designing a portable material handling device for a customer. The device will need to be powered by a large battery (24v, 40a, 10 amp hours). I've done some preliminary research, and it looks like I'll need two sealed lead acid batteries, a low voltage disconnect (LVD), a state-of-charge indicator, fuse, and two chargers (each with their own charge management electronics). Its seems like a ridiculous amount of work to spec and integrate all these components for such a common problem!

I'm thinking someone must retail a "battery management system" for lead acid batteries that handles charging / display / LVD in one nice little box. Kind of like a UPS, but without the inverter. Can someone point me in the right direction?

Thanks in advance

 

[VEBill]

Most (all?) of those requirements are standard with the normal, consumer, portable 12 volt lead acid battery packs. Such battery packs are a dime a dozen (as you probably know). I wonder if it might be better, faster, cheaper to use a 12 volt pack because they're so common, and then add a 12 VDC to 24 VDC inverter? The 40A is a little bit challenging, but should be available.

 

[TomDOT]

24v is more common in marine stuff. Googling "Marine 24v batty pack" gives hits which look useful.

 

[MiketheEngineer]

Or 18 volts in Dewalt equipment and many other portables

 

[NuclearNerd]

Or 18 volts in Dewalt equipment and many other portables

Without a full set of specs, I'm leery about using power tool batteries or consumer power packs. Neither specify their maximum discharge current, and in the case of power tool batteries the manufacturers won't warrant their use in anything but their own tools.

The marine power pack lead looks promising, but I'm still not finding a match. The best thing I've seen so far are Lithium-ion (or Lithium-polymer) replacements for lead-acid batteries. These are billed as "racing" batteries (since they're lighter) and have all the BMS circuitry on board. I'm currently looking for a reputable supplier.

This seems like such a common problem though. I can't believe no one makes a little electrical box to monitor and protect off-the-shelf lead acid batteries.

 

[itsmoked]

I think you do need to look in the R/C arena. They have a lot of high energy high density packs. A lot of places will make them custom for you and there are some sophisticated charges in there too.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[telecomguy]

Wireless telecom world uses 24VDC. Lots of power systems available with these features at

http://www.eltek.com

http://www.alpha.com

http://www.lineagepower.com/?page_id=285

http://www.delta.com.tw/product/ps/tps/tps_main.asp

<tg>

 

[IRstuff]

What are the service conditions, i.e., how much of the 40A and for how long?

LiPOs are rage for RC, but there are some limitations on voltage values and ampacities, which I think would result in something like 4 LiPO batteries. LiPOs also tend to be finicky about how they're charged.

TTFN
faq731-376

 

[NuclearNerd]

Telecomguy is on to something. After I googled "DC UPS" and "telecom", I came up with these two products which might be ideal (I still have to read the specs in detail):

Pheonix Contact
Siemens