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I'm interested in the notion that consumer grade ups overheat. The apc range, which I've used are line interactive which I take to mean that the inverter side continually runs the load, and a brown out causes the external supply to switch to battery, rather than external supply failure causes...

I'm fairly sure that it's 1kwh for 1square meter, not 6. Which is why the testing standard is as it is.

I've got a hangover now.....

Yes yes YESSSSSSZZZ

Ah, go on, hit me baby ?

I used to look after milk floats which were powered by 36 400ah 2v cells. First sign of failure was warm cells. When they get older, plate resistance is not uniform across the surface and this causes localised heat. The effects of this is to slightly buckle the plates, shedding some material in...

Oooh, ya get a hit with all the likes at the bottom of a thread reply.... Is this the Facebook of environmentally sound power production?? ??

A good mppt SCC is able to accept high panel voltage, so you series the panels or a combination of series parallel. This lessens the voltage drop on a cable run.

Hi, can't give my opinion on the first question, but for the second, if you are used to fla you'll know that for every 1amp you can only realistically use 1/2, to keep the battery in good condition. Different for lithium, for every 1amp, you could use all of it, or for extended life 8/10's. This...

Interesting thread. I have a system based on a 48v 100ah battery. I think I might struggle with what you are proposing.

Hi, I did a run time to get a basic capacity test for the bank. It was around 4 hours @20amp drain. I used a heat gun, like Will does. It was very simple and without a watt meter. My batteries are charged with an EpEver nd series I tracer. This is custom programmable and has been rock solid so...

Hi Jamie, this is my small mobile set up. I have 70 20ah 3.65v cells arranged in a 5p 14s config which at full charge is around 5kwh. The cell chemistry is nmc. I've just bought another 70 cells to double capacity. Obviously you know all about the apc. My apc has never let me down.

Just tiny length of heat shrink would have done the job, can't believe they (BB) neglected that. Someone should be blushing today....

Sorry to hear that. I do need to cycle mine a few times occasionally, there seems to be no rhythm or rhyme to it, although certain battery voltages seem to make it happen. I'm a stubborn old git, and when something like this happens I try to find a pattern in the fault. As a last resort, I'd be...

Not sure why, but mine sometimes takes a few attempts to get it to start. Same thing regards the fan. The amount of time you have to press the start button seems to vary slightly. Mine always fires up in the end.

Tbh, the apc is probably close to its upper voltage cut-off, but most of the time I run my pack at 4v-4.1vpc for longevity. Afaik, the inverter is happier at the higher end as its drawing less amperage from the pack.

For Delmar

Hi Delmar, interesting project ?, re your inverter, I use an APC smart ups running on 14s lithium. I've used apc's for a few years. The battery capacity meter always flashes empty on mine, the ups is happy enough, it's just it works out run time calculating the capacity it thinks it should have...

Hi Calvin, my cells are flat prismatic NMC EIG cells. They charge to 4.2 maximum and working voltage is nominal 3.6v. Each cell is rated at 20ah and has a sustained rate of 5C and can handle 10C for short bursts. I think they were primarily intended for electric vehicle use. They are arranged in...

I have an Ep Ever, I have learnt to completely ignore the soc reading. I judge soc based on terminal voltage and how much current the battery is drawing at that time. Agm has a slightly lower internal resistance so can still ask for higher current at relatively high voltages. Soc is normally...

With my nd series itracer, equalise is higher than absorbtion /boost. Its turned off by making duration zero. My boost time is set to 20 minutes. I got really confused while setting mine up to begin with. It kept saying illegal parameter, until I worked out sequencing the voltage when programming.

The idea of an equal battery Bank is all cells of same age and type, because what's known as internal resistance (IR) needs to be as close as possible. This is so the batteries in the bank charge and discharge at the same rate. Very important. Tbh, if you've invested in 3 new ones, they really...

SCC, is solar charge controller. tbh, once a cell is beyond a certain point, they don't recover.

I've never been close to rich/well off/middle class etc. But I am resourceful. Because I have dedication to learning about the things I need. It doesn't take much work to find info on how to care for your equipment (even while being stored) and a motivating factor might be the inability to...

Sorry reread... Agm.

If they are new, and lead acid flooded, could it be possible they were supplied dry with acid to add? If they are sealed vrla agm/gel lead acid, 0v means they are scrap. If they are lithium, be VERY CAREFUL about putting a charger on them as overheating and fire could result. The bottom line is...

Lol, I did suggest checking the load/duty cycle. The only way is with a watt meter as previously mentioned (not by me) ?

I still feel the system is a bit under spec'ed. 450ah is 225ah in reality. Those batteries will need a fairly decent current for bulk charge and a long absorbtion time. If the load is operating while this is happening, the sun hours might have difficulty keeping up. This gets worse in sub...

Has anyone heard of FOZHS? Stands for forward only zero hot-spot. I think this is also to do with partial shading conditions where the shaded cells would be fed current. Worth a Google.

A battery capacity test would be useful

The panels are 235w 37v 7 amp

Sorry, I will try to be clear. Imagine 2 panels connected in parallel. Same voltage as one, but double the amps. Now connect this block with two more panels in a series connection. I'm wondering if this is possible

@madmax, you might have answered the question. The panel will be bogged down. My only other option is to add 2 more panels and configure 3s2p. Ideal voltage achieved to maximise mppt

Atm the panels are connected 2s2p and the open circuit voltage will be around 74v at standard temperature. If I connect 4s, I'll be above the max voltage at lower temperatures. I was considering paralleling 2 panels to double the current but retain the 37v and putting these in series with the...