Off Grid Telecommunications Plant Battery Project

LDO6420

I have the opportunity to get about 18 of the EnerSys 2GU-13 Batteries used for Central Office Telecommunications Backup.  The Batteries are Flooded Lead Calcium Flat Plate, Styrene Acrylonitrile Copolymer case, 4V with (4) Cast Lead Post terminals [Capacity @ 8hr Rate (Ah): 1220 (c8), .]12.4"L x 15.1"W x 27.3"H (max ht), 436 Lbs. 

Battery Features 

High Rate Performance - Copper inserted posts assure efficient high rate

performance with minimum connector re-torquing requirements

• Life - The battery has an expected design life of 20 years at 77˚F under float service

• Loads - The battery is designed to handle complex load profiles requiring high load

currents as well as long duration discharges

• Construction - Cover made from Flame Retardant PVC (UL94-V0/L.O.I.32%) as standard

• Application - The battery is ideally suited for power plant, power switching

and standy power applications

• 100% initial capacity

Question : Could this be a alternative battery backup source that's a bit more advance than Lithium?  Would you recommend this for full off grid configuration due to the 1230 ah? Do anyone want some of these batteries if I have extras left over once the Solar configuration is complete?   My ideal is to get 12 of these total.  Setup 4 banks of 3 in parallel to equal 12 volts then series these two bankes to  make  24 Volts the series those two to make a 48 Volt Giving me 14640 ah. for the off setup. 

Marc Kurth

To get to 48v, you must connect all twelve 1,220 ah 4v batteries in series. This will give you 1,220 ah at 48v. 

So, [email protected] = 58,560 watt hours.  

Remember that each battery is 4v x 1220 ah = 4,880 watt hours. Twelve of them will be 58,560 watt hours regardless of how you wire them.

If you need more storage capacity, you must add additional strings of twelve.

I am curious - In what way do you feel that this is more advanced than Lithium?

Marc

mcgivor

They are in essence two lead acid cells in series to provide a 4V nominal, no they won't outperform lithium, nor are they more advanced by any stretch of the imagination,  in fact they are primitive in their basic chemistry, but if the price is right, why not. The intended  service duty is backup, not cyclical, so life expectancy may be dramatically reduced in an offgrid application especially with deeper cycles on a regular basis.

Having 12 in series will provide 48V nominal at their rated capacity, not quite sure what your theroy is regarding parrallel series is, but what I can say is you'll need sufficient charging capacity to recharge depending on discharge levels.This is a common mistake, having a battery capacity greater than the charging ability, it would be useful if you could provide information on how you intend to charge such a large capacity bank.

Estragon

+1 on a string of 12.  Doing 3 in parallel gives you 3660ah @ 4v, not 1220ah @ 12v.

Marc Kurth

One additional comment: Do your homework regarding what to do with these once you are done with them. Some (I repeat some) lead-calcium formulations are not recyclable by most battery recyclers.

I can tell you about a very bad experience where a customer bought some used telecom batteries really cheap but had to pay some costly fees in order to get rid of them. In one case, in particular, I suspect that the seller knew exactly what he was doing - and made the disposal someone else's problem.

Again, this may not be the case with these particular batteries. I am only suggesting that you perform some due diligence to see what you are stepping in.

Marc

mike95490

>  expected design life of 20 years at 77˚F under float service

hype : expected

Disqualifies for for daily cycle service:  float service

These are large, but simple, standby batteries.  Nothing exceptional about them at all, but they will be really heavy to move out when they go bad

Marc Kurth

Along the same lines of my previous post: IF there are fully recyclable using conventional methods, they are worth close to $160.00 each just in scrap lead value in my neck of the woods. (Junk lead pricing varies regionally) Think about that as compared to what they want to charge you. If the price is too low, there must a reason.

Also, remember that each of these batteries contains 45 liters of electrolyte, so you need to look seriously at how you will contain and mitigate any leaks.

mcnutt13579

We have had a couple customers who used this type battery and the results were disappointing.  They are designed to handle some load profile but only very infrequently.  Remember at a telecom plant they have a huge diesel generator.  These batteries keep the systems running until the generator starts, or in an emergency, until the generator can be repaired or a spare brought in on a trailer.  How often do you think that happens?

LDO6420

mcnutt13579 said:

We have had a couple customers who used this type battery and the results were disappointing.  They are designed to handle some load profile but only very infrequently.  Remember at a telecom plant they have a huge diesel generator.  These batteries keep the systems running until the generator starts, or in an emergency, until the generator can be repaired or a spare brought in on a trailer.  How often do you think that happens?

Can you elaborate more on what was disappointing   available. ?  

mike95490

Telcom batteries are designed for only a couple dozen or so discharge cycles, as backup generators come on line.

They are designed for long Float life and are often swapped out at about 50% of warranty period (15 year battery exchanged at 8 years to insure freshness) and then resold as having lots of life left in them,  Lots of life in Float.  

They will seldom last 6 months in deep cycle application with solar, new or used.