First time to 50% SOC

[mena661]

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 connected it. It did do the full 55 amps right off the bat though. When I checked it a few hours later (not sure how long), it was at 14V even. I'm going to put in an on/off switch on the output of the converter to make sure it's off completely. I'll be honest, I'm not liking this converter so far. I used the BD1093 to top off the batteries this time. Only needed to run the EQ on it twice (checking SG after each run) then a connected the Iota for 8 hrs. Checked the SG again and it was right at 1.285 in all cells (58F/14C).

For those interested, here's some pics of the CG.

[mena661]

smkettner wrote:
Do you have the TS default to inverter? If the coil uses power it should come from the cord or generator, yes?

Never checked this but I should. It would definitely save some power. It seems like it's defaulted to the genny which is weird.

[time2roll]

Do you have the TS default to inverter? If the coil uses power it should come from the cord or generator, yes?

[mena661]

HiTech wrote:
Wow! So many hidden parasitic draws in devices these days.

Jim

These MH's sure do draw a lot of power. Even the transfer switch uses power. We used only used 33Ah per day in the 5th wheel (in the summer) and that was with a lot of TV watching and even some furnace use. I will say we don't use nearly as much furnace in the MH as the 5er so that's a bonus.

[HiTech]

Wow! So many hidden parasitic draws in devices these days.

Jim

[mena661]

Went out on another trip last weekend. Only used 200Ah this time (3 days) mostly consisting of TV watching, BIL's music, multiple cell phone charging (had inlaws out with us this time), and wifi hotspot use. Actually not too bad considering we had 9 people at the campsite on Saturday. Before the trip I did a thorough energy audit and determined where most draws are coming from. The front and rear entertainment systems have an idle draw of 3.6A. Total idle draw with my inverter on is 5.65A. I cut that down to 1.8A by installing two remote on/off, 3 plug cords. Now I can turn off the entertainment centers when I'm not using them. I also unplugged the comfortaire mattress controllers during the day. All those standby's were eating up 160+Ah's.

[mena661]

My batteries disconnected from the coach and allowed to sit will self-discharge 1% per week. Their SOC did not drop 5% while performing the testing. SG is still 1.285 in all cells. The only thing that dropped was surface charge. 100% full voltage is 12.73 with no surface charge left after a complete 24 hr self-discharge with my batts. I don't pay much attention to voltage because it's misleading. I only use SG measurements to make determinations. And SG did not drop below the 1.285 mark.

When I first connected my bank to the IOTA, it did the same quick 55 to 53 amps as it did this time but held 53 for considerably longer. The bank was at ~85% SOC at that time. This time it held 53 for a bit then tapered pretty drastically but the bank was for the most part at 100% so that was to be expected. I will say that my old Paramode would do 58 amps in a similar situation and taper quickly from there.

BTW, they are at full amp hour capacity now. I made a thread about it last year sometime.

[MNtundraRet]

I had forgotten that your batteries are quite new, and may not have had many cycles yet. If that is the case you current situation may be normal since the batteries may not have been cycled enough to reach potential full AH capacity.

Without some discharging to 50% and recharging to "full" charge, the batteries can drop to 95%soc over a few days. There were some discussions on this subject back in Dec. or Jan. on some "HiTech" posts.

Mark B.

[MNtundraRet]

mena661 wrote:
I was able to get the IOTA into boost mode manually. I was measuring some draws and in the process brought the battery voltage down to 12.73 (batts in float prior to this). The converter was unplugged from 120V but still connected to the batts during the measurements. Total time disconnected was about 30 minutes. I noticed when I first unplugged the converter that there was a .25A draw on the batteries for about 10 seconds then it dropped to nothing (batt disconnect switch off). If I were to guess that was the IQ4 doing some voltage sample or something. When I plugged the converter back in, it jumped to 14.4V within 20 seconds or so and after a few minutes climbed to 14.8V. As soon as I plugged in it did 55A, then dropped quickly to 53A and held that for a couple minutes then started tapering. Batteries were 100% full (1.285 SG) prior to my measurement testing.

A side note: the front entertainment center draws 13.9A while a TV show is on (inverter draw from batteries). Almost half of which is the TV itself (6.2A). I'm going have to check how it's mounted and see about getting my Vizio in there instead.

My MH is still sitting in storage (6 months to date) waiting for the never ending winter to end. The 2 new T-105's are fully charged and maintained by a 9-watt solar panel.

When I go out and either start MH engine for alternator charging, or the generator using the WFCO 45 amp 3-stage charger, I will see the 14.4+ volts and only about 5 amps tapering to 2 amps or less in about 15 minutes.

That is what I would expect for 2 6-volts batteries in series stored on "disconnect". The batteries do not prey on each other. The %soc is likely 99 to 100%.

I your case it surprised me slightly to your amps reading 55 to 53 amps (you did not say what it tapered to) at this point. Batteries in parallel do prey on each other even on disconnect.

This rate of charging suggests to me that your %soc may have dropped back to around 95%. Your battery bank is 3.5 larger than mine with only a 55 amp 3-stage charger which may account for the difference.

However; others with a battery-bank closer to your size might say this is normal. It may have to do with the deeper battery-cells of the L16's. Did all the cells check out at 1.285 sg or is there a weak one?

[mena661]

I was able to get the IOTA into boost mode manually. I was measuring some draws and in the process brought the battery voltage down to 12.73 (batts in float prior to this). The converter was unplugged from 120V but still connected to the batts during the measurements. Total time disconnected was about 30 minutes. I noticed when I first unplugged the converter that there was a .25A draw on the batteries for about 10 seconds then it dropped to nothing (batt disconnect switch off). If I were to guess that was the IQ4 doing some voltage sample or something. When I plugged the converter back in, it jumped to 14.4V within 20 seconds or so and after a few minutes climbed to 14.8V. As soon as I plugged in it did 55A, then dropped quickly to 53A and held that for a couple minutes then started tapering. Batteries were 100% full (1.285 SG) prior to my measurement testing.

A side note: the front entertainment center draws 13.9A while a TV show is on (inverter draw from batteries). Almost half of which is the TV itself (6.2A). I'm going have to check how it's mounted and see about getting my Vizio in there instead.

[mena661]

smkettner wrote:
IOTA did not even get to make a full swing at these batteries before the BD went to work. I think it hit 14.6 at some point and when you saw 14.0 it may have dropped to 14.2 absorption. .2 could be the loss in the wire? Or maybe it was still on the way up in bulk. Or bulk timed out. Hard to pinpoint unless you record battery vs converter voltage every 10 minutes.

Like I mentioned before the IOTA was on the bank for a week. It was in float when I unplugged it and threw the BD on them. That's sort of what I do typically (I use the HF charger for finishing normally). I have left my old Paramode on the bank for a month before just to see if in time the SG would come up. It never got the SG up high enough. As a matter of fact, it came up very little. So little I thought I might have done permanent damage to my bank by letting them sit not fully charged for so long. Thank goodness they were fine but I'm betting they lost a little capacity with that experiment. The IOTA floats basically at the same voltage as the Paramode so I don't know what it would do that's any different than what the Paramode did. Sure, the IOTA has the stirring thing but 15 mins at 14.7V won't work for finish charging (EDIT). It DOES work for destratifying as that's how long I (used to) perform that maintenance item for. 15V for 2-3 hrs does work every time without fail. 3 years so far on these batts with a 1.285 SG. Exact same as new. I'm going to stick to my regimen for now. Look at the bright side, I don't have to do nearly as many equalizings as before but I think that's due to MEX's top charging advice.

[time2roll]

mena661 wrote:
I used the BD1093 to top off the batteries this time. Only needed to run the EQ on it twice (checking SG after each run) then a connected the Iota for 8 hrs. Checked the SG again and it was right at 1.285 in all cells (58F/14C).

IOTA did not even get to make a full swing at these batteries before the BD went to work. I think it hit 14.6 at some point and when you saw 14.0 it may have dropped to 14.2 absorption. .2 could be the loss in the wire? Or maybe it was still on the way up in bulk. Or bulk timed out. Hard to pinpoint unless you record battery vs converter voltage every 10 minutes.

[MEXICOWANDERER]

Just like a woman. If you give them hugs and kisses often, it'll save you from buying diamond rings to save your life in the long run.

[BFL13]

Yes, even after only one 50-90 my 6s need a dose of 15+v to get back to 100%. But with solar doing maybe 80-95s it is easy to get back to 100. Doing a few 50-90s in a row means a lot of work on "recovery" once back home on shore power. So it seems that going deep makes a big difference.

OTOH before he got solar, smk claimed to be taking his 6s down below 50% and his 6s still work. Hard to tell what the deal is there, since smk also does not like to monitor things. Of course with 6000w of solar, he could have only 3 AH remaining capacity and not even notice. 🙂

[mena661]

smkettner wrote:

I am just thinking the IOTA will do better than the Paramode.
I am really surprised these L-16 really need all the extra handling that is given.
Let us know.

You solar guys don't discharge your banks deep enough to get into these kinds of issues. Also, I know you adjusted your controller down but you more than likely have a longer absorb time than my converter which might be enough to get it up to baseline SG or close enough where you won't notice the capacity loss. I'm really not doing much more than what BFL does with his GC's. The only difference is the height of my batts requires some attention paid to stratification reduction. You guys don't have to worry about that so much. But with the IOTA's occasional 14.7V stir, that's one less maintenance item to perform.

MEXICOWANDERER wrote:
That really is the key. If you are happy with what you got value and performance wise at the end of the life of the battery so-be-it.

Thanks much MEX.