First time to 50% SOC
DW and I pigged out on amp hours on our last trip to the beach a week ago. According to the Victron, we used 364 Ah in 3 days. Oddly, the Iota did not go right to 14.8V like it did when I first connec...
Forum Discussion
mena661 wrote:
Thanks all. I was under the impression that the Iota went right to 14.8V. Didn't know it was like other converters that ramp to that voltage. That would explain the behavior. Although I do wonder why it went to 14.8 when I first connected it. About solar, it's on my list.
Your Iota did go into "bulk" charging within a few minutes, and the output voltage would have been 14.8 volts. To see it you would need to read the voltage at the charger output terminals. Your converter/charger was working since to read the current (amps) outputting maximum rated 55 amps.
Also; 3-stage chargers do not ramp voltage. Their output voltage is 14.4v , or whatever set or designed to be.
Reading voltage across battery-terminals is a different animal all together. Voltage shown starts with the battery's actual voltage (12.1 volts at 50% charge state) and then rises as battery gets charged.
You mentioned the Iota read 14.8 volts (across battery-terminals) almost immediately when tested on your newly installed L16 batteries. Normal reading since the batteries were almost 100% charged.
Everything has to deal with size of scale. My MH came with a 45 amp 3-stage charger and 220AH battery-bank. This represents charger-output of 20% of battery-bank capacity.
My Schumacher 40 amp multi-stage charger and separate 80AH 12v Trojan represents charger output 50% of battery capacity.
Your MH with a 55 amp 3-stage charger and upgraded 720AH battery-bank represents only around 7.5% of battery capacity.
A normal (recommend) ratio would be charger-output of 20% of battery-bank capacity. That means a 150 amp charger in your case. As mentioned by others having a good sized solar-panel setup can allow for a smaller charger size (80 or 100 amp).
To recap, your 55 amp charger was working correctly. It just was too small for recovering from a 50% state to "full" in a reasonable time on your battery-bank. Similar to a 10 amp charger on a single 65AH battery. Works but very slow.
Your comment about adding the BD charger would have worked at the time since both chargers would stay in "bulk" mode for a good amount of time because of the large size of the battery-bank.
