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By hit it hard, do you mean discharge rate? Or charging rate?
What would you suggest for the 139 amp-hour 12 volt battery for a maximum (safe) discharge rate?
Where in telcom we generally hit it hard, and there for don't get as many cycles out of them.
I'd suggest no more than a C/10 to C/7 discharge rate, and a C/5 recharge is hitting it hard, as is using 14.8V to recharge in bulk mode. 14.4V seems to do it all on my DEKA model, consistently. Case doesn't get warm, when recharging.
Telecomm companies establish parameters for maintenance based on OEM guidelines. OEM is aware that their client wishes the very highest degree of performance reliability. So a operating lifetime max hours is agreed upon. Max hours of guaranteed reliability. Zero non performers. The batteries have a specified level of max discharge at which Telecomm shuts down transmission and the batteries go dormant. The percentage of charge remaining is unknown to me. We allow many plants to go as dead as they want. And rely on equipment's power supplies to shut down or brown out. Thou some sites we do terminate service for the sake of the batteries.
Technicians operate by holy writ in the form of rote. They follow maintenance, troubleshooting and testing exactly and precisely according to company doctrine. It is all well documented then entered into a computer database for reference, study and analysis. Job one is the repeater must not fail. The largest piece of this information is trending. With out an accurate history of how the battery lives, one may declare it deceased early. Or worse off, wait to long to bury it.
Transcribing telecomm writ to a usable form for RVers can be deceptive. What worked excellently for telecomm may not be in the best interest of somone whose use of the used batteries may be totally different. Telecomm is after 100.0% reliabilty at the expense of trade-offs. Are you aware of the tradeoffs?Most telcom plants trade cycle's for depth or discharge. As with any battery the less you use it, the longer you can use it. Where in telcom we generally hit it hard, and there for dont get as many cycles out of them.
Understand this point. After an outage, telecomm batteries have forever and a day to recharge. Do you? Charge amperage ceilings are based on acheiving ultra maximum longevity. This is a moot point if telecomm batteries spend a majority of their golden years connected to shore power with incidental short interruptions for boondocking. In that scenario following Telecomm rote is the wisest choice as it most closely mimics what the batteries were designed for.Every battery mfg. has recommendations on how to use their battery. No one says you have to. But pumping to much current into a plant is a sure way to ruin it. And Telcom has restrictions on recharge. We do NOT have forever and a day to recover a plant. We have FCC regulations that state our systems have to maintain between 8 and 24hrs of backup at any given time. We recharge our plants as fast as we can. Its not uncommon to have an outage just hours after a previous one. This is the worse case. We also have to have the equipment to properly supply power to the load, and be able to charge the batteries ASAP. Even a back up generator or a fire alarm panel has regulations on max recharge time.
When things shift to off-grid rote gets chucked out the window. Calculated charge maximum absorbsion voltage is not the same animal. Neither is maximum absorbsion voltage. Only float voltage remains thec same.Many battery MFG. understand the different use of their batteries. In the case of these UPS12-490's they call for a float of 13.65 ± 0.15 VDC average per 12V unit. While recognizing they may be used in a cycle service thus also state 14.40 to 14.80 VDC average per 12V unit for such use. Upping the voltage while still maintaining the recommended amperage increases the wattage of absorbed power.
If you stick like glue to telecomm rote prepare to rum your generator a lot longer. You are mimicking unlimited time value recharging via your generator. Your fuel and your time.
When I generator recharge 3300 amp hours of 24 volt battery it is absolutely different from charging using CFE shore power. One is 500+ amperes. The other is 120 amperes (the 4024 Trace). Coursing 120'amperes through a 1650 amp hour battery / 2 banks is a gentle recharge. Life with public power available is absolutely unlike recharging via a generator. The issue is time. The issue is money. Lots and lots of money. To do an in-frame on the Kubota is around five thousand dollars. Add that to $3.35 fuel, filyets, lube oil and labor and it makes shore power recharging calculations totally, completely and absolutely irrelevant. To the point of becoming absurd. Cost of kWh hr transcribed to usable battery kWh includes the ACTUAL cost of fuel plus generator wear and tear. I an not a telecomm company and nothing I manage even remotely can serve as a model for both economics nor management.Trust me not much we do is a model of economics either. In many cases with remote prime power sites. We would rather buy a new generator ever 2-3 years and burn thousands of gallons of fuel. Than have to purchase a new battery plant every fuel years. Its it alot cheaper to fuel and replace a generator than replace a battery plant.
One of the things I love about Telco batteries is they are always available. They take a 48v string and toss it out. We get to run to the pile and pick out the best of whats left to make out 12 or 24v systems. I know I have a huge pile of batteries at home that were tossed aside. I currently have 8 180ah AGM batteries I am "reviving" from the telco world. they were taken out of service and left on a pallet for 2 years with out a charge. I have been able to bring them back to life quite well. And they currently follow their historical trending withing 80% of rated capacity. These cells were deemed to have a 7yr life span. They spent 9 years in service. 2 on a pallet and are about to be connected to an outback GS series radian, where I expect another hand full of years out of them in UPS mode.
The biggest problem with most telco batteries is the amount of calcium they have. during discharge the plates swell. Over time this causes plates to short and the battery than no longer works.
I would not hesitate to use old telco batteries. But I certainly would not buy them new for this use. For the money there are batteries that will serve the offgrid world better. But for cheap/free batteries, why not finish them off.
When you get two guys from different ends of the battery business, and telecom business, in the same post, you should find a moderator that can make this a sticky for Telecom batteries. I think you can take this post above to the bank.
I will be stunned if I don't get 7 years or more out of my Deka Telecom battery, knowing how I care and use it, thick plates and acid rich concentrate at 1.300 SG.
Thicker acid mats reduce plate area. If you understand the strength and weakness of a telecomm battery they will suit the purpose perfectly. But cycle lifetime ratings for telecomm are wholly different than cycle rating for off grid. Cycle ratings for telecomm are ONE HUNDRED PERCENT DISCHARGED - ZERO PERCENT REMAINING. There is a huge difference in how batteries are rated.
Theoretical average sampling (assumed)
You guys are comparing apples to oranges. Ratings and performance wise. Like golf car and scrubber batteries telecomm batteries are more competitively priced than other AGMs and for exactly the same reason. But they have DEFINITE PURPOSE strengths and weaknesses.
I would not go Honking on Bobo the telecom battery, with the big inverter, making coffee, running the hair dryer or electric heater. But running parasitic load, LED lights, a small TV, anything that is not demanding instantaneous heavy demand draw, is probably just fine. My belief is you'll have to practice some electron conservation, or start stacking more batteries so you do have enough battery to cover heavy amp high usage draws.
The batteries are big, heavy, and like lumbering low and slow charging, as well as low and slow discharging, with steady current draw. Your usage in an RV should try to match those parameters, if you'd like these types of batteries to work for you.
I have a generator I can run if I want electric brewed coffee, while recharging the battery too with the generator. But I camp solo, no wife, no hair dryer, no instant gratification needs required at the touch of a switch or a finger. I do tend to still rough it a bit, after all, it is camping for me, not a Motor Home... big difference there.
I run 2700 to 3000K 60watt equivalent Cree A19's mixed 50/50 with a 5000kw 60 watt Cree A-19. The bulbs were more expensive when I bought them 2 or 3 years ago, but the price is dropping fast.
2700K Cree A19
In 5000k Daylight color
Take your pick
It's football season, I may spend more time out at the TT watching football on the TV, drinking a beer, and in general cycling the battery and generator regularly to keep the gas in the Honda generator fresh, and the jets in the carburetor clean. As well as cycling the Telecom battery. I don't believe I have gotten much below a 60 to 65% SOC yet.
I don't know how deeply discharged mine was when it only took 21 amps. What I do know it that with the Mega Watt 30 amp, and this battery rated 158AH @ 20 hrs amp rating, I am right at the C/5 max rate. I put a good 14 days in a row on mine the first two weeks of Sept. It's held it's voltage at 12.88V and a month of sitting in my garage in some heat had it down to 12.84 when I just float charged it again and topped it off. I will probably check it again come December 1st, for holding voltage, and top up as necessary.
I would think that a sunny day, and with one 158 amp hr battery, my 150w solar panel aimed at the sun on a sunny day for 3 to 4 hours will more than suffice to top charge the telecom battery before letting it rest again in storage.
What I am seeing, time and again, is that it takes about 3 to 3.5 hours for the battery to get the last 4 or 5% charge while recharging, back into it... There is no forcing it, no rushing it... doing so with a generator is a huge waste of fuel. And it is imperative to get that last 5% back in, to prevent sulfation, as soon as is possible, if you want the battery to last. These batteries don't sit well if not stored completely, fully charged, that is considered abuse. The cell site keeps them top charged constantly, if power goes out, as soon as power comes back on, these batteries are being recharged fully to 100% SOC. You need to mimic and duplicate that condition, as best you can, while dry camping.
So it's now Oct 25th, and I took a storage charge reading on my DEKA Telecom 150 amp AGM battery, and I was at 12.82V. It has not been on float, or in use, or anything, just sitting there. 3 hours and 40 minutes brought it at 14.40V from the Mega Watt 20 from 1.44 amp charge rate down to a 0.13 amp charge rate, same as before on the RC charge meter.
This battery is very, very consistent so far with what it takes to top charge the battery. Just slow, but steady for 3 to 4 hours to get it fully loaded up.
And they brag about their Amish quality. I'm betting they don't use Amish workers in much of a percentage. Or maybe no percentage at all.
You need to tour the factories, I think you will be surprised to see how many are Amish. The idea of a particular religious being more quality oriented, is just hype.
I've toured the Lance Camper and Travel trailer factory. The employees in there don't warrant my confidence as a general contractor to pay the premium price Lance tries to charge for their travel trailers... the added value is not there... not when you look at all the run down junk cars without valid current registration parked in the employees parking lot. English isn't even a second language for 90+% of the employees on the shop floor. True story..., BTW, I notice minute details like that.
Why don't you go to the Crown Battery website, and see what they recommend for charging procedures, volts, amps, charge rates, etc, etc. Once you find it and read it, post up the link to the website, for others to learn from.
Borrowing a charger to charge your brand new expensive batteries is not a good idea, buy the correct, non compromised equipment you need to maintain the batteries correctly, or don't bother.
I make a point of dumping my tanks before starting the drive to go home, and dumping 5 or 10 gallons of water in the gray tank and the black tank, with bleach, for the drive home, so it sloshes around, and then dump again once home, usually a days worth of driving and bouncing around to loosen things up. I haven't noticed my tanks having a foul odor yet. Sloshing disinfectant on the drive home, so far, so good.
A couple of comments- why no liquid cooling? If case space is a concern, liquid would certainly help, moving the radiators outside.
As to the whole design-
Two-stage charging presents a challenge to engineer when flexible voltage plus flexible time is involved.
This is taylor made for an Arduino- depending on the precision you need it would be trivial to measure current, voltage, temperature and whatever else you need to control a digital potentiometer controlling the megawatt.
Whose budget is this coming out of, yours, or mex's? :h
I bought a VW e-Golf last week.. 24.2kwh of lithium power. VW's clever engineers didn't see fit to water cooling either on the battery pack or the 7.2kwh chargers, but I assure you, it will suck down 30 amps of 240V for 3 to 4 hours to take the battery pack from empty to full, air cooled.
What is really bad for that battery is sticking a 50kwh DC charger and blast charging to 80% SOC in 20 to 30 minutes, with no cooling system present. Really, really not good for a very, very expensive Li battery pack.
A regular old EVSE for me, thank you.
DIY EVSE system for EV's.
Best quality, or the highest price ? If you always think you get what you pay for, get a Kocera panel. Probably none better, but I don't know of any that are worse either.
My cheap ones don't work very good in the shade anymore !:M
My cheap MegaWatt works in the dark, in the shade, and in daylight.
In some cases the difference between a battery charger and a Converter is the paint job.
But in most cases it is filtering and regulation.
Battery chargers tend to be unfiltered rectified AC Some (non-smart) are not regulated so you go (sixty or 120 times a second) from zero volts up to around 15 or 18 and back to zero This is ok for charging batteries. but not so good for powering electroincs.
CONVERTERS have (at least most of 'em today) Filters on them.. So the output is 13.6 volts DC with very little AC ripple. In fact in my RV is a very sensitive radio. I have, many times, chatted with folks over in Italy, or France or Germany on digital modes pushing a great whomping 30-40 watts into the wire (Antenna) and they are doing the same.. A radio that sensitive will notice things like AC ripple on the power leads. My TS-2000 can not tell if it's running on Batteries, Converter or both the converter is that clean. (it runs on 12 -15 volts very nicely).
But the converter has both very good flitering, and very good regulation..
(I mentioned some older ones, Like the Magnetek 6300 which actually had two outputs.. Both were unfiltered and unregulated.. one was tied to the battery though and that one the battery acted as both filter and voltage limiter. Boiling dry if the voltage got too high.)
Your Kenwood TS-2000 is also a $1500 radio... KiloKilosixSanDiegoZoo...
It should keep at least 2 years. I'd be more concerned about the temperature that it freezes at, and will it split the tank it's stored in, if it expands during freezing, since it is 68% distilled water, 32% urea.
If you are worried, buy a 2.5 gallon tank or two at walmart, when the low warning light comes on, after burning off all the older adblue.
BTW, what does the owners manual say for the engine manufacturer, for recommendations?