These Telecom AGM batteries generally have both + and - posts on the same side of the battery, as opposed to opposite ends which makes locating and wiring them much easier when there a couple dozen powering a cell phone tower in the case of a power outage.
They seem to come in surplus acid, and acid starved versions, and I am not sure the benefits/detractions of this either way.
Some have been reported to not be able to accept high amperage rates. One 150AH 100LB version I know of is said to require only ~22 amps to nearly instantly reach 14.5v when 50% depleted. This is a very low absorption limit, and the battery would also likely exhibit a lot of voltage drop under high amp loads, such as powering a microwave through a high wattage inverter.
As a comparison I own a 68LB 90AH capacity AGM battery and it can accept 65 amps for ~25 minutes before voltage rises to 14.4v.
One really has no idea how these tellycom batteries were treated in storage, or how many times they were cycled when they were the backup UPS system in a cell phone tower. They could be an awesome deal and give great service to an RV dweller, or be no better a deal than any other AGM, and there is the chance one is buying a sulfated battery that has only 60% of original capacity remaining. There is no way to tell, visually, one way or the other. And believing the claims of the seller is rarely wise.
One would need to test the perfomance of the battery, and this is done my monitoring voltage and amperage acceptance and the time during charging, and voltage and AH consumed during discharge. Meaning having the measuring tools, and the desire to observe them throughout the charge/discharge cycles to get an idea of the battery's remaining capacity.
Without this one is effectively either trusting the seller and or rolling the dice, or just ringing the 'just fine' bell having no idea one way or the other.
If I were to acquire one of these( say 155AH capacity) I'd discharge it to 12.2v, recharge it at 40 amps until 14.4v was reached and hold 14.4v until amps tapered to 0.75a. I'd record how long it accepted 40 amps before voltage reached 14.4v for future reference, and how long it took for amps to taper to 0.5% of capacity at 14.4v at 77f
If it took 8 hours for amps to taper to 0.75 when held at 14.4v, I'd be less thrilled than if it took 4 hours.
I'd then discharge it again, to ~12.1v, noting voltage at certain times during discharge for AH removed, then do the 40 amp until 14.4v recharge thing again and then hold 14.4v to see how long it took amps to now taper to 0.75.
I bet after the second recharge cycle it would show some improvement in capacity ( higher voltage held for the same AH removed)and it would take less time for amps to taper to 0.75a at 14.4v. If they were abused, the possibility of some capacity recovery is pretty good, if one can hold absorption voltage for long enough and perhaps even go a bit higher monitoring it closely for rising temperature.
Please look at Lifelines 'conditioning' procedure on page 20:
http://lifelinebatteries.com/wp-content/uploads/2015/12/manual.pdf
And do note they are the only AGM manufacturer that recommends this. That is not to say it cannot be safely done to other brands with the proper human monitoring of the procedure with the correct tools ans knowledge to do so
Even if it performed poorly and was obviously nowhere near its 150AH capacity rating, I bet it would still deliver pretty good service for a while, but personally I would want a new fresh battery so I knew it was recharged properly and not overdischarged regularly.
These Tellycom batteries have not been employed in RV duty for very long yet, so we do not know how they will perform in such duty, longterm.
They could be an very good battery, or marginal, and one will not know either way until it is asked to perform, and can then see how it performs, and for how long.
They do seem to be VERY heavy, for their rated capacity, and this usually is a very good thing in a deep cycle lead acid battery, unless there is only one battery, and it is asked to power very high loads for a while via an inverter, by itself.
In such a scenario the voltage would drop fast and might have the low voltage alarm on the inverter screaming all too quickly, even if the battery is still 90% charged.
So they are a roll of the dice until we get some longevity reports by those who understand their loads, and the number of total cycles the batteries delivered, and who had recharged them correctly during their life powering an RV.
