Nightjar, your system is obviously not a 'failure', maybe just not as efficient as it could be, so as you point out, why spend big bucks on it until it actually needs renewing :Y:
condor22 said:Nightjar
"Sorry RR, can you get back to your original post"
If you are referring to his fridge testing, that's a different thread, lol.
condor22 said:Nightjar
"Sorry RR, can you get back to your original post"
If you are referring to his fridge testing, that's a different thread, lol.
Ded Driver said:RR, I believe the problem you are experiencing with your battery on a high charge current is that it may be just taking a 'surface charge', & therefore not really fully charging. This is why smart chargers with a 3, 5 or 7 stage charge profile do a much better job, especially on deep cycle batteries.
condor22 said:Nightjar, I like the wind genny, great on breezy nights when the sun aint shining
RR - A smart charger whether DC-DC, solar or mains will typically start at a "soft voltage" and also depending on battery SOC.
They also typically start in BOOST until they figure out that SOC and then move through the 3 stages as required. (I'll leave out the 7 stage functions in this post). They all vary to some degree, I'll leave it to others to check the specs of other brands, but here are mine.
As mentioned I have the Redarc BCDC1220 DC-DC @ 20A, which is a 3 stage charger and the Projecta IC1500 mains @ 15A, which is 7 stage. Assuming the battery is depleted sufficient to need Boost mode here's the comparison;
REDARC/PROJECTA
Boost V - increasing to 14.5V - 20A/ V - increasing to 14.4V - 15A
Absorption V - fixed to 14.5V - A - decreasing to 3.0/ V - fixed to 14.4V - A - decreasing to 2.25
Float V = 13.3 - Min A/ V = 13.7 - Min A
Subtle differences, but in essence they do similar things as will other brands. So the higher V i.e. 14.5 is ok until the battery Floats.
FYI The Projecta is programmable to 2, 4, 8 and 15A output. I have 2 battery capacities 100AH and 130AH, so both chargers will handle the 10-20% charge rate of both batteries.
The biggest fallacy I've noted with those not understanding charging is the charging time. If you have a 100AH battery, use 50AH and charge with a 20 A charger it will not take 50/20 = 2.5 hours to charge. It will be much longer. In boost mode it might take a couple of hours to reach 80-90% SOC at which point it goes in to Absorption mode with a reducing Amp input. This might take another couple of hours and will vary depending on charger, battery condition and size, ambient temp and if under load during charge, to mention a few. A good guide is do the simple math and double it. This applies to MPPT solar controllers as well.
condor22 said:There's nothing wrong charging a 115AH at 15 amps Boost. I've been charging batteries for years at that rate and my last one replaced lasted 10 years. But I rarely exceed 25% of capacity, both by design and process.
Going lead crystal means quicker charging, but less often as you can draw deeper.
The other thing with portable fridges is that because they are limited in size, many tend to stack em full. They work less efficiently when you do that as the cold air does need to circulate. About the only time mine is fuller than normal is on the way back from shopping, but that is a shortish time period. So round containers next to each other might not utilise all the space, but they actually are better for the fridge operation.
condor22 said:Might be worth checking your charger or the batteries, probably batteries first. AGMs shouldn't bubble at that charge rate. Both my batteries get 14.4/14.5 V in Absorption mode without an issue. Then hold 13.7 (van) on Float, in fact that's exactly what it currently is as my monitor is bluetooth to my phone.
The other thing I'll mention is that my monitor also has a Temp transducer on the + terminal and the battery will usually be at ambient even when it's only just in double digits. That in itself shows it's not getting hot during any charging stage.
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