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pianotuna's avatar
pianotuna
Nomad III
Apr 21, 2023

telcom battery bank

Hi all,

This winter I was not home. There was an early heavy snow and the solar panels on the rv were covered all winter.

So far I've had about 19 amps going into them for one hour. After 24 hours, resting voltage was 8.1

I did another 20 minutes and voltage while charging started at 10.1 and ended at 11.3.

I'm hoping that when I have some shore power, I'll be able to rescue the telcom jars.
  • The usual scenario for telecom site batteries is design for long float life with perhaps a dozen or so major discharges. But long term survival at low voltages isn't in their job description.

    Paying up the yangying for a lifeline means getting incredibly thick plates. Controlled overcharging sheds substantial amounts of plate material. But if they're super thick it's like having a checking account overdraft protection plan.

    But the chances of survival for a battery with lesser thickness plates is less.float maintenance for 10 years will consume a chunk of plate layer as well.

    By the way Don if you ever get your hands on a regular transformer rectifier battery charger you can throttle it with your variac. A Fred Flintstone grade sort of adjustable charger.
  • I'm pretty sure I have reduced capacity. But then, I have (blush), turned into a power pole princess. I do love my load support and since I've had the Magnum inverter I've blown one breaker in 7 years (4 of which were as full time).

    I'll most probably limp through this year with the telcoms.

    I'm on a 23 day trip with 15 stops and all of them have atleast a 15 amp service. Some have multiple 15 amps and my destination has a weak 50 amp.
  • I haven't performed a standardized ampere hour test but I did do this...

    Let it sit as I described. Then operated a tube heated 24 volt heated reservoir ResMed BiPap for 17 hours (total) via a 300 watt Samlex PSW inverter, disconnected everything then it sat for (perhaps) 4 days.

    Observed voltage 12.69

    Keep in mind this battery was picked up March 2012 and stood standby for many years being maintained at strictly observed Concorde float values

    Conclusion: like me the battery is obsolete so formal testing would be moot. I mentioned this merely as being curious. There is no reason to be prejudiced by assumption. Until I can walk again or have motive assistance I seem to be "stuck" in an environment that has near infallible electrical service. My neighbor across the street is a regional bigwig for CFE the government electricity agency :D
  • MEXICOWANDERER wrote:
    A few months ago I posted a note about recovering a 11 year old neglected Lifeline AGM. To make a short story shorter, I ended up leaving the battery connected at 15.5 volts for two weeks.

    No it didn't heat up
    It did not lose 1 gram of weight
    But yes, it finished holding 13.3 volts @ 55° for a week afterwards.

    Neglected? Yes. Disconnected for 3 years


    Was the capacity affected at all? I have revived car batteries before that were DOA some worked with a lower capacity, most didn't... I know that agm can handle a bit more punishment than regular ones, but not a lot more
  • Hi Mex,

    Your thread inspired me to try to fix these. So thanks again for all your help.
  • A few months ago I posted a note about recovering a 11 year old neglected Lifeline AGM. To make a short story shorter, I ended up leaving the battery connected at 15.5 volts for two weeks.

    No it didn't heat up
    It did not lose 1 gram of weight
    But yes, it finished holding 13.3 volts @ 55° for a week afterwards.

    Neglected? Yes. Disconnected for 3 years
  • pianotuna wrote:
    Things are looking good for the battery bank.

    Started shore power bulk charging at 62 amps rising to 84 amps. After 5 hours 59 amps. At 11 hours down to 10 amps float charging. 15 hours in and float is 1 amp


    Do you have a proper load tester? might be worth checking them after they are full and have rested an hour to see if the very low voltage state they got to have impacted their capacity. mind you if you don't have a reference to what they were before it's just the current state not really a comparison. I know normal batteries including agm can have issues if they get to low.
  • Things are looking good for the battery bank.

    Started shore power bulk charging at 62 amps rising to 84 amps. After 5 hours 59 amps. At 11 hours down to 10 amps float charging. 15 hours in and float is 1 amp
  • wa8yxm wrote:
    If those are edison cells and likely glass jars.. You can boil 'em to desulfate if you have to.. Just don't boil 'em too long (By Boil I mean overcharge)



    wa8yxm,

    They are a variation on AGM but used in cell towers.

    I do wish I had edison cells.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    If those are edison cells and likely glass jars.. You can boil 'em to desulfate if you have to.. Just don't boil 'em too long (By Boil I mean overcharge)

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