To clarify if needed, my AGMs are not "telecoms" so I don't know how much of this might apply to telecoms. Several members here do have AGM telecoms in their RVs.
On the 20% rule, don't forget that is only for the Bulk stage when under about 75% SOC at the start of the recharge. At about 75%, the acceptance rate at 14.4 volts falls below 20%, so it is impossible to meet that rule after that point. You will go straight into the Absorption Stage and amps will taper.
That is not a bad thing as long as you do go to the final 0.5/100 thing often enough (somehow) when shallow cycling on solar.
I got one 27 back up in SG using Mex's advice. Low and slow all the way to 16v. Took about 18 hours. Started with the VEC1093DBD at 4 amps with Equalize blinking, so it would continue to 15.8. SG was just into the White when that stopped and it said FUL. Then I put on my PowerMax set to 16 volts and ran that for a few hours. Don't know what amps that was. SG came up nicely into the Green, and it is now on Float. Doing second 27 now.
Mex did say that 15.8 is NOT the same as 16!
What a difference from ten years ago fighting with those horrible 27s to get their SGs up into the Green! Sure helps when you know how and have the right equipment. Takes a lot of your time though. Wouldn't be good for a working stiff getting back from camping Sunday night and heading off to work Monday morning!
