Have nice set of Telecom Batteries--Now what?

Apollos2 · August 2013

Hi y'all! I'm a newbie to the whole solar thing, but, I am a Telecom equipment installer and have recently acquired 20 x 12v (which were wired into 5 strings of 4 batteries) Northstar 170ah batteries and an Eltek/Valere Compact DC Power System (Rectifier). All of the batteries were in working condition when I decommed them and installed new ones in their place, the Eltek/Valere is NIB. What do I have here when it comes to powering my home and what else would I need to do that. Also, I have continual access to used, but in very good condition telecom batteries, so I can have virtually as many strings as needed to run my entire house. Are these good batteries for this type of application? I know I need more stuff I just need to know what kind of stuff and how much.

H2SO4_guy · August 2013

Re: Have nice set of Telecom Batteries--Now what?

Welcome to the forum!!! You have come to a great place to get knowledge and ideas to explore new options. First off, what part of the country are you in?

How do you intend to use the batteries? Off-grid? Backup power in case of electrical failure? Do you have grid power? I see you have a rectifier, is it set up for -48 VDC like most Telco's? How do you intend to charge these? Are you getting any RE energy inputs like Solar, wind, or hydro?

Let us know and we can help much better.

Skip

BB. · August 2013

Re: Have nice set of Telecom Batteries--Now what?

Welcome to the forum Apollos2.

I have moved your question to its own thread--It should be a lot easier for you to direct the Q&A towards your needs/goals.

First, get the batteries on a reasonable charging/float setup (charge once per month, or float 24x7, etc.). You don't wan the batteries to age/sulfate as they slowly discharge (need to recharge to >90% state of charge once every 1-3 months or so, depending on battery construction and age).

Next--Step back and look at your home/loads. An off grid system is not cheap to implement and maintain (although--You have appeared to address a huge chunk of the initial and ongoing costs with your battery "mine".

If you can get the actual part numbers for the batteries, it would be helpful. The batteries may be designed to float for 20 years, or have 10-15 years of cycling. Depends on what was ordered.

Regarding your loads--We can do it several ways.

Ideally, you measure/estimate your home's loads. Then look at conservation (usually the best investment you will make). Then revisit your loads (peak watts, average maximum watts, Watt*Hours / kWH, etc.).

Generally:

1 kWH per day (30 kWH per month): Just enough power for some LED lights, small water pump, laptop, radio, small tv...
3.3 kWH per day (100 kWH per month): Add a refrigerator, well pump, clothes washer--Pretty close to a "normal" electrical life with lots of conservation.
10 kWH per day (300 kWH per month): Add another fridge/freezer. Central heat (natural gas/propane for heating/cooking).
33 kWH per day (1,000 kWH per month): Normal North American Home--Possibly add electric hot water or some electric cooking/etc.
100 kWH per day (3,000 kWH per month): Add Air Conditioning/Heat Pump, electric cooking/hot water...

A 3.3 kWH system is nice for a full time cabin, or emergency backup power for a home (power lines down from ice storms, hurricane etc.) where power will be out for weeks to month or more. For short term outages (days or 1-2 weeks) that occur once every few years, a genset with stored fuel/natural gas may be the more cost effective solution--And supply more kWH per day than a solar power system (which will cost a lot more).

Larger systems become more expensive and require more maintenance and are no weekend project.

Power is a highly personal choice, and we want to make sure that you get a system design that meets your needs (both power and budgetary).

-Bill

Apollos2 · August 2013

Re: Have nice set of Telecom Batteries--Now what?

OK guys and or girls,
I have an Eltek C48212A Compact Power System NIB (also a freebie from a friend). I live in Eastern KY. My local Rural Electric Cooperative Corporation (RECC) does not have a energy buy-back program, I checked. I will get the #'s from my batteries in the next day or two. As our average electric bill hovers around $250 per month, even after I've put up a clothes line and installed LED's in 3 of our most used ceiling fans and our entire bathroom lighting, I also turned our hotwater down to 90 degrees. We have 2 LED TV's and 1 older solid state TV. We are planning on building a new house and I am intent on integrating Solar power into the new structure so we can eventually get completely off the grid. I would "like" to start at the 33kWH range and grow from there into being completely "OFF GRID" with all or most of our ammenities. I also have an older RELTEC INVERTER that is pretty big that was used in a 10,000 AMP telecom system, could this possibly be integrated into the system? I will collect the #'s from that peice of equipment also and post them. I pretty much have access to any and all equipment needed to charge the battery plant, of any size. The question is can I use Solar in conjunction or instead of the AC that was used to power these units?

Blackcherry04 · August 2013

Re: Have nice set of Telecom Batteries--Now what?

I'd check back with your RECC, while they will not buy the power from you, they should " Bank " it. I am in Central KY and mine does. Even with free equipment it's hard to beat not having to fool with keeping up with a off grid system. Having a battery back up and the ability to go on or off grid is a big plus. To offset a $250 a month bill you'd have to have around 16 KW in PV to break even.

BB. · August 2013

Re: Have nice set of Telecom Batteries--Now what?

At 33 kWH per day--That is a pretty large system. I would suggest you get a Kill-a-Watt type meter to measure the energy usage of all your plug in loads, and use a whole house type monitor to spec. the larger loads.

To give you a rough idea for an Off Grid system. Designing based on our common rules of thumb (1-3 days of storage, 50% maximum discharge):

33,000 kWH per day * 1/0.85 inverter eff * 2 days of no-sun * 1/0.50 maximum discharge * 1/48 volt battery = 3,235 AH @ 48 volts

And to charge such a battery (5% to 13% typical solar rate of charge):

3,235 AH * 59 volts charging * 1/0.77 panel+controller derating * 0.10 rate of charge = 24,788 Watt Nominal Array

Based on where you live and using PV Watts near Huntington WV, fixed array, tilted to latitude:

Month    Solar Radiation (kWh/m 2/day)
1      3.19     
2      3.67     
3      4.54     
4      5.02     
5      5.27     
6      5.42     
7      5.31     
8      5.22     
9      5.00     
10      4.43     
11      3.38     
12      2.73     
Year      4.43

Toss the bottom three months (use generator for bad weather), we get 3.67 Hours of sun average per February:

33,000 kWH * 1/0.52 system eff * 1/3.67 hours of sun per day = 17,292 Watt array minimum

So, it would appear that your system should have somewhere around 17,292 to 24,788 Watt array (minimum to nominal size) and this will carry you around 9 months of the year.

Using VERY ROUGH NUMBER for an OFF GRID system, that is something like ~$40,000 for a battery bank and ~$40,000 worth of solar panels. Add ~3 MPPT charge controllers (3x$600) and 6kW AC Inverter/Chargers (1-3x $3,200 each) + another 1/3-1/2 for electrical/mounting hardware/labor/permits/shipping/etc.

Your thoughts?

-Bill

Apollos2 · June 2014

Re: Have nice set of Telecom Batteries--Now what?

BB. wrote: »
At 33 kWH per day--That is a pretty large system. I would suggest you get a Kill-a-Watt type meter to measure the energy usage of all your plug in loads, and use a whole house type monitor to spec. the larger loads.

To give you a rough idea for an Off Grid system. Designing based on our common rules of thumb (1-3 days of storage, 50% maximum discharge):
33,000 kWH per day * 1/0.85 inverter eff * 2 days of no-sun * 1/0.50 maximum discharge * 1/48 volt battery = 3,235 AH @ 48 volts

And to charge such a battery (5% to 13% typical solar rate of charge):
3,235 AH * 59 volts charging * 1/0.77 panel+controller derating * 0.10 rate of charge = 24,788 Watt Nominal Array

Based on where you live and using PV Watts near Huntington WV, fixed array, tilted to latitude:
Month    Solar Radiation (kWh/m 2/day)
1      3.19     
2      3.67     
3      4.54     
4      5.02     
5      5.27     
6      5.42     
7      5.31     
8      5.22     
9      5.00     
10      4.43     
11      3.38     
12      2.73     
Year      4.43      
Toss the bottom three months (use generator for bad weather), we get 3.67 Hours of sun average per February:
33,000 kWH * 1/0.52 system eff * 1/3.67 hours of sun per day = 17,292 Watt array minimum

So, it would appear that your system should have somewhere around 17,292 to 24,788 Watt array (minimum to nominal size) and this will carry you around 9 months of the year.

Using VERY ROUGH NUMBER for an OFF GRID system, that is something like ~$40,000 for a battery bank and ~$40,000 worth of solar panels. Add ~3 MPPT charge controllers (3x$600) and 6kW AC Inverter/Chargers (1-3x $3,200 each) + another 1/3-1/2 for electrical/mounting hardware/labor/permits/shipping/etc.

Your thoughts?

-Bill

OUCH! Sorry for the extended delay in my response to you guys but my work takes me out of town quite a lot. Anyway, the company I work for is getting ready to do a MAJOR battery replacement project nationwide. I don't have access to ALL of these batteries but to a large amount of them, and they range from 90lb maintenance free to 800lb wet cells all in working condition just is the warranty has ran out. With that being said, I have access to all items necessary for battery charging from an AC source with Generator backup, of just about any size and up to 12,000 amps. I also have access to all required cabling at 10% of scrap price...750MCM Flex/Kcmil down to #6 AWG Flex! I know, I have a virtual "MINE" of little nuggets for this kind of thing. I would like to build my own solar panels since that seems to be the most economical way for this type of project, and there's no sense in spending money un-necessarily:D I am going to my warehouse today and will get Model #'s of batteries, rectifiers and inverter. Once again, sorry for the time lapse

BB. · June 2014

Re: Have nice set of Telecom Batteries--Now what?

If your company is looking for somebody to manage the removal of the old batteries, poster 'ajbelcher' has sold some good/surplus batteries here over the years... He may be able to assist.

Be careful with any batteries you obtain. They need to be kept on float/recharged ~every month to keep from going dead in 3-12 months. I would suggest that a minimum of 1% rate of charge. With a large battery bank, that is not an insignificant amount of energy.

1,200 AH * 56 volts floating * 0.01 rate of charge * 1/0.80 charger efficiency = 840 Watt load
0.840 kW * 24 hours * 30 days per month = 605 kWH per month

That is about 2-3x the amount of power my suburban home uses per month and would cost something like $150 per month for power.

A 1% rate of self discharge is pretty high (older flooded cell bank), and it is possible that a "good bank" may be as low as 0.1% -- Which can dramatically reduce your power needs. Be careful of what type/condition the batteries are in.

-Bill

mike95490 · June 2014

Re: Have nice set of Telecom Batteries--Now what?

reason #1 for end of warranty time swap out of "good batteries". They are about to die. Warranties are carefully calculated to be no longer than the cells will reasonably last. So you will end up load testing batteries, and tossing many of them within the year. don't pay more than the recycle plant will give you for them.

Just saying, there is a reason large companies swap out battery packs.

Reason #2. some of the telecom batteries are rated for FLOAT service, and will only last a couple dozen deep cycles. How often does a phone company have to drop back to battery power ? Just a couple times in the battery lifetime.

inetdog · June 2014

Re: Have nice set of Telecom Batteries--Now what?

mike95490 wrote: »

reason #1 for end of warranty time swap out of "good batteries". They are about to die. Warranties are carefully calculated to be no longer than the cells will reasonably last. So you will end up load testing batteries, and tossing many of them within the year. don't pay more than the recycle plant will give you for them.

Just saying, there is a reason large companies swap out battery packs.

On the other hand, since big companies tend to be very sensitive to the actual standby time they can get and do not want to oversize a battery bank to cover degradation, they call a battery "dead" and subject to replacement when it has only 80% of its original capacity.
If the batteries were otherwise well treated and reason #2 does not come into play, then they may still be useful for RE for years.

zoneblue · June 2014

Re: Have nice set of Telecom Batteries--Now what?

Apollos2 wrote: »

OUCH!

Welcome to our world. Unless you are a millionaire you will have to lower your expectations some, and that is part and parcel of the solar arena. In my country (NZ) 25kWh/day is the national average consumption. I think its a little higher in the states due to climate, but if thats the average, cmon man, you can do better!. Conventional eletricity is produced at huge cost to the environment, and in the case of nuclear threatens our entire civillisation.

Conservation is the first place to start. Broadly we approach it like so:
- water heating: solar thermal, heat pump, spare PV power, low flow water fittings, propane
- space heating: passive solar design, insulaton, insulation, insulation, woodstove
- cooking: propane
- appliances: high efficiency versions
- lighting: led

We realise we have shifted some of our loads sideways to fossil fuel, but for now its considered that electricity is not a great way to make heat, as theres so many conversion losses. However probably the most important things is an attitude of doing more with less, and having fun doing it.

When you have done all that, then you will find, as we did, that solar PV will fit real easy into your life, and wallet.

Renz · September 2017

Hi there, I had to dig this post out of the archive as the subject was matching with a question that you guys may be able to answer.

How did the used telecom batteries went? 5 years later, how long did they last? Did you have any problems?

I'm looking into installing some ex-telco units for off grid

mike95490 · September 2017

Renz said:

......
I'm looking into installing some ex-telco units for off grid

If you are looking for about 100 cycles (3 months), you are OK. If you are looking for longer term reliable power, pass on the used batteries, or any Telcom Float duty battery styles.

Renz · October 2017

Hi Mike,

Is this from experience or just from theory

Is there any way to contact Apollos2 via email

mike95490 · October 2017

Telcom batteries are only designed for FLOAT service. They are not designed for deep cycles.
Additionally, they are sold to unsuspecting buyers as "having years of Float life" left in them, but they are too old
for us to continue to use, so here, buy them and you can dispose of them.

mcgivor · October 2017

Renz said:

Hi Mike,

Is this from experience or just from theory

Is there any way to contact Apollos2 via email

You could try a PM, but it appears he/she has not been active since 2013, if learning is part of the experience, by all means purchase the telecom batteries , but.pay only scrap value,, at least you would gain some knowledge before moving on to serious batteries, which can support your loads, however remember batteries die of old age, hence the reason they are being replaced, although telecommunications companies are conservative with regards to life expectancy, they are not deep cycle, nor designed for cyclical use, but you could have some fun along the way, just don't have any great expectations.

softdown · October 2017

The sailing community has a lot of good things to say about deep cycle gels. Gels can also last a very long time when not used for deep cycling.

So I might guess that it all "depends".

Marc Kurth · October 2017

I will respectfully add that some Gel battery designs can provide very good deep cycle service in certain applications. A 15+ year lifespan is not uncommon under great operating conditions. BUT these batteries were specifically designed for heavy cyclic use - not standby/backup duty. I work with some 2v gel systems that are rated for 4,000 cycles at a typical 33% DOD and 2,700 at 50% DOD and 1500 cycles at 80% depth.

Yep. it all depends.......

Have nice set of Telecom Batteries--Now what?

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