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50% dod outdated
#21
So if you look on the other pic it shows all that data. It was on 11.7v (all day thunderstorms)
Battery is about 80ah

This is confirming what sternwake said and what i always knew renogy and their clones and many controllers go into float wayyy to early.

We know its too early cause as soon as the solar dies off it immediately drops and holds at about 75% BUT since its not shunted that could be the load who knows without a proper batt monitor
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#22
Flooded batteries will vary fairly widely in amperage they accept at absorption voltage when near or at full charge,

but accepting 3 amps at float voltage is a sure sign they are not fully charged and that more time was required at absorption.

Amerage accepted at 13.2 or 13.7 will be a fraction of that if voltage were 14.7, 1/2 to 1/3rd, so big numbers at float voltage are a flashing red light that the absorption phase is way too short.

Confirm with a hydrometer, a good one, not a plastic ez-red style, which IME are both inaccurate and imprecise.

Do note that if the batteries have been chrnoically undercharged you will not be able to get specific gravity back upto teh 1.275 level without an EQ charge of upto 16.2v. One should likely disconnect all loads when doing a 16.2v EQ charge and definitely disconnect an absorption fridge's circuit board when allowing these voltages to occur.

initiate EQ charges only after the battery has spent at least 2 hours at absorption voltage, do not allow 16 amps to push voltage past 14.8v, allow it to taper t o3 ish amps or less then alow 16.2. it will likely take no les than 6.2 amps per 100Ah of capacity to push a flooded battery to 16.2v.

It is easily noticeable how much more voltage a battery will retain when discharging, after an EQ charge returns speciic gravity back up near or to the general maximum of ~1.275 if it is possible to increase it, meaning the sulfation is not too hardened and undissolveable . Batteries intended for cold climates might be 1.300, batteries intended for hot might be 1.265 max. I recommend that owners of newly purchaed batteries take note of electrolyte levels in the cells, the amperage the batteries accept at absorption voltage when the specific gravity is as high as it can go, for future reference and comparison.

tailor absorption voltage and absorption duration so that the battery can get to or very near maximum specific gravity on a day with god sun whenthe previous nights overnight discharge represenets a good average of typical use.

If your solar controller does nottttt allow 16.2v, you can bypass the controller, and hook panels directly to battery, just make sure to not allow anymore than 16.2v, and you might hav to angle the panel away from the sun to keep it from going over.

Actual plug in equimment which allows 16.2v is not readily available for purchase. I use an adjustable voltage power supply as Automatic 'smart' underchargers sicken me with their lying flashing green lights.

Chronically undercharged batteries, caused by a solar controller that does nothold absorption voltage for long enough, pretty much will not respond to longer durations, until after the EQ charge is performed, The EQ charge might not be effective if the sulfation has indeed hardened, but it stands the best chance of restoring capacity
[-] The following 1 user says Thank You to sternwake for this post:
  • Roadtripp (04-15-2019)
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#23
Ok for now i just set float to 14.6v (im underwired and dropping .2v at battery...work in progress).
Heres the amperage after 3.5hrs

EDIT: phone was charging...amps - .81


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  • Roadtripp (04-15-2019)
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#24
On the old Motorhome I want to see what amperage my gel cell batts are receiving prior to controller dropping to float voltage. I just remembered the inverter itself uses about 22 watts so once it’s in float the display on the Outback CC reads about 1.8 amps. Which is a waste of the solar potential. 
 This costly sytem has the opposite issue. There are so many adjustable parameters it takes a while to figure them out. There’s grid timers, return amps, refloat amps, ...........a long list ? I can see the day when I have a van and one battery.
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#25
(04-14-2019, 02:05 PM)Ddarnell Wrote: Cause Ive had all the chinese MPPT's and none of them seem to be up to muster.

The tracer line allows one to hold absorption voltage for 3hrs.  Not optimal, but in my case I am at endAmps before then.
---
frater/jason
FT around El Paso:  159" Promaster, 570w
blog | campervan | RVwiki

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#26
(04-14-2019, 04:51 PM)Wabbit Wrote: If it's been a cloudy week, when the sun does come out, I hold 14.8 the whole day until amps in are under 1.5a at 14.8. That's what the mt50 meter can do paired with a compatible tracer type CC.

How are you doing that with the MT50?  I haven't needed it but it'd be nice to have in the back pocket.
---
frater/jason
FT around El Paso:  159" Promaster, 570w
blog | campervan | RVwiki

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#27
How long absorption is to be held is Also dependent on the amount of amps avalable to get the battery to absorption voltage.

lets say 5 amps  from a 5 amp plug in charger into 100 AH heathy battery depleted to 12.54 in 8 hours from a true full charge. Lets keep solar out of it for this example..

if still new and healthy and depleted to 12.54 volts.  5 amps will take a few 2-4 hours to get the battery upto 14.8v, assuming the absorption / maximum voltage that the charger is seeking to rais evoltage as high as and then  hold ist at 14.8v.  it will reach absorption voltage in the 90% charged range, and only 2 or 2.5 hours the battery might  be in the 99%+ range.  Perhaps less, these are not actual numbers  I pulled from any data sheet.

Same battery same depletion level, but the charging source has 25 amps available to be instantly applide to the 12.54v battery  battery will accept 25 amps for about 15 to 20 minutes before it reaches absorption voltage, it will reach absorption at about ~75% charged, and holding 14.8v from there it will likely take 3 to 4 more hours for amps to taper to the 0.7 to 1.7 amp range.

So one example holding Absorption for 2 hours completes the charge, in the other example it is closer to 3.5 hours.

Same battery but not so healthy basically less amps can raise battery voltager much faster to absorption voltage, reaching absorption Voltage at a lower state of charge.

Now throwing in teh vararies of solar and available and strength of sunlight, and one can see how any pigeonholed absortption duration, can be like throwing a dart  at a moving dartboard, bindfolded.

Basically once th eabsorption voltage is reached, the charge controler is seeking to maintain constant voltage, and the amperage required to maintain that voltage, keeps tapering.

So end amps, as a float trigger,  assuming the charging source knows the amperage into the battery, vs total amperage flowing into batteries and loads, then thn one can say when amps taper to 0.67 at 14.64 volts, this specific battery can be considered fully charged.  The beauty of flooded batteries is this assumption can be confirmed with a hydrometer.

If the Hydrometer reveals the battery accepting 0.67 amps at 14.7v is not truly fully charged, the max expected SG  determined earlier in the battery's  life, then there is likely still some sulfate on the plates.  Increase absorption voltage duration, see if specific gravity rises.  If not, then try the Equalization charge of 16.2v.  Check electrolyte density with hydrometer closely eery 15 minutes, account for rising electrolyte temps of the warming battery. Stop the 16.2v max, when electrolye no longer continues to rise, or the battery starts getting much hotter quickly.  120f is the absolute max but than does not mean 118f is fine and dandy. Once it gets above 105f in sub 80f ambients it wil continue to heat quickly. This temp rise can and will help dissolve hardened sulfate, but it also might not.  the hydrometer will reveal all, if it is used and gives repeatable measurements.  Even if it is off 0.010, it should always be off 0.010 and readis compraable to readings take earlier in the battery's life when fully charging.

If the battery does get this hot, and SG only responded a little to this forced overcharge, with the intention of driving the semi hardened sulfation from the plates, the next one initiated once the battery has cooled to room temperature,  might or might not do anything.  Hard to say without trying.

the EQ charge can be dangerous as the battery will be offgassing a LOT. it will stink like burning rotten eggs and this should not be breathed. 
But after an EQ charge, the battery will basically be returned to its maximum potential remaining capacity, which of course might still be so dismally small it is time for replacement.

The hardenening sulfation can be prevented by reaching true full charge often, the EQ charge can be seen as a hail mary attempt or just necessary maintenance to slow the capacity decline.

If performed regularly before the sulfation gets a chance to harden, then one can really achieve excellent longevity/cycles/total KWH delivery of the flooded lead acid battery.

It can be a lot of work to achieve ideal/excelent/maximum possible  flooded  battery longevity.  One can simply replace the battery more often and just treat the batteries as servants, instead of being a servant to the battery. Abuse the servants badl, intentionally or ignorantly, they will quit, early , and steal something on their way out, and leave some feces in an airvent for you to discover at some later date.

Programmable controllers can do pretty well, when programmed correctly, but getting it perfect each time when the typical usage can vary widely, especially when vehicle dwelling, is near impossible.

Be aware of what ideal is, and draw your own line in the sand as to how far you want to take it towards there.  Spendng 400$ on the perfect solar controller,  well 400$ can buy a lot of lead acid batteries too, if you do not mind the process of replacing them more often, and the environmental consequences.  Takes a lot of energy to transport  batteries to the recyclers, recycle the lead and sulfuric acid and plastic casings, and form them into new batteries, and to then transport them to the retailers.
[-] The following 1 user says Thank You to sternwake for this post:
  • Roadtripp (04-16-2019)
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#28
(04-15-2019, 12:50 PM)Ddarnell Wrote: Ok for now i just set float to 14.6v (im underwired and dropping .2v at battery...work in progress).
Heres the amperage after 3.5hrs

EDIT: phone was charging...amps - .81

I’m not sure but if you have voltage drop due to undersized wiring might you want to set the absorb and float voltage higher to compensate?  Or are you saying in your edit that the phone charging was causing the voltage drop? 
 It’s a moving target as sterwake mentions. Some controllers have small voltage sense wires direct to the battery. The Morningstar and Flexcharge have these. I’ve wondered why the Outback does not. I’m not sure about the Rover or Chinese controllers.
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#29
I think the phone was just sucking up that amperage(0.81) from the display of the charge controllers total output.
Controllers without sense lines are wise to use a short length of the fattest possible wire which can fit in the terminals, to minimize  the voltage drop from controller to battery.
My initial solar wiring was 12awg from panel to controller then ~8 more feet of 12awg from controller to battery.
When I added the pvl-68 unisolar stick on panel, that panel got its own 10awg wiring and the 130 watt kyocera got 8awg, and the controller was moved much closer to the batteries.
The 12awg sheathed ancor 3 wire former solar delivery cable got retasked  into part of the wiring harness that delivers higher voltage to my headlamps through relays.  More voltage there= brighter headlamps.
Finding excessive voltage drop and rectifying it, is more work and more money, than having used proper thickness wire initially.
MPPt controllers really benefit from fatter wiring from panel to controller as MPPT Dc to DC magic, converts that excess  panel voltage above battery voltage, to charging amperage.
If in doubt, oversize the wiring gauge.  especially on difficult wiring runs, like from roof to charge controller. Upgrading wiring  from controller to battery is usually not so much extra work, but it sucks to have to do any job twice.
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#30
High voltage- Series. Less loss, smaller cable.
Power companies use immense voltages to transit power when the can get away with it.
345,000 volts. :Bulge Eye Smiley:
Sometimes dweller in 237k miles '07 Grand C-van w/ a solar powered fridge and not much else
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