Evening guys

 

ive got a 5kw hybrid kodak with a up5000 battery using the bms cable that came with the inverter so far no communication issues at all.

 

At this stage the battery is just for loadshedding or cable theft..😂 so the grid is my main supply to loads..

to the question.. so ive noticed the battery charges about once day.. even when I havent used it and the battery level indicator lightd never switch off.. 

should I switch the battery of to preserve it until the crap starts again.. or will it be fine?.. I dont want to shorten the battery lifetime unnecessarily.. im new to these fancy things and not very clued up with them.. some help will be appreciated..

You have the Comms established. The Pylontech battery is telling the inverter what it wants and the Inverter is playing along. The Pylontech BMS is well programmed and will take care of itself in the case. No need to worry about the top up charging. Also if the Comms fails the inverter will shutdown charge and discharge so you are protected.

 

11 hours ago, Steve87 said:

You have the Comms established. The Pylontech battery is telling the inverter what it wants and the Inverter is playing along. The Pylontech BMS is well programmed and will take care of itself in the case. No need to worry about the top up charging. Also if the Comms fails the inverter will shutdown charge and discharge so you are protected.

 

Thank you very much 

Whilst I somewhat agree with @Steve87 in that some manufacturers' BMS are tweaked to compensate for long periods of 100% charge (we see this, for example, in the Hubble S-100s), I would suggest that you read the warranty that came with the battery. Pylontech warranties (both US and UP series)  requires the battery to be used in a system that charges and discharges on a daily basis. 

So in the event of a warranty claim, the manufacturer may reject it.

If you want to use the battery in strict accordance with the manufacturer's warranty conditions, you could consider doing one of 3 things:

1. Simulate loadshedding on a daily basis, i.e. discharge to say 40% and then charge it again, however this would make your electricity bill more expensive due to losses;

2. Only charge the battery to, say 70-80% (if you can);

3. Install some panels, run the batteries to, say, 10% in the night and recharge from solar every morning. By far the most cost effective.

 

Edited June 5, 20224 yr by YellowTapemeasure

I would agree with the fine print here. But when a warranty is actioned I can almost guarantee that a daily cycle basis is wide open to interpretation. 

I have actioned a warranty before on lithium batteries and in all cases they did not ever bring up the conversation of this fine print. However, I will not dispute the fact of this condition. In all honesty, if you understand Lithium Iron Phosphate chemistry you will know that cycling is important especially in a UPS application. I would not be comfortable to leave these batteries at a float for extended periods. I would at least cycle at least once a week. And I would not float high, but then again the Pylontech will again dictate that float charge. 

The manufacturer will always have a log of what that BMS has done so there is no hiding away unfortunately. @YTM is correct I would add a panel or two and try to cycle. But in my book a conscious effort to discharge once a week would be my effort. 

A bigger broader discussion here on terms and conditions but Pylontech are a worthy battery manufacturer. They are in my opinion market leaders in the product that they sell. Their batteries have some derated charge and discharge patterns that I don't like but hey it's their product so they can choose the rules of application. 

10 minutes ago, Steve87 said:

I would at least cycle at least once a week.

That's exactly what Hubble (unofficially) suggests with their AM-2s, so I agree.

Thanks alot for the advice guys 

On 2022/06/04 at 8:24 PM, Bronwynn said:

Evening guys

 

ive got a 5kw hybrid kodak with a up5000 battery using the bms cable that came with the inverter so far no communication issues at all.

 

At this stage the battery is just for loadshedding or cable theft..😂 so the grid is my main supply to loads..

to the question.. so ive noticed the battery charges about once day.. even when I havent used it and the battery level indicator lightd never switch off.. 

should I switch the battery of to preserve it until the crap starts again.. or will it be fine?.. I dont want to shorten the battery lifetime unnecessarily.. im new to these fancy things and not very clued up with them.. some help will be appreciated..

Hi there . If you are not cycling the battery you should look at how they treat the battery in storage. Generally when you buy a battery it will be at 50% SOC ,there is a reason for this. At this state of charge the least amount of degradation takes place. 

The storage voltage should be 3.3V~3.4V per cell. So that would be around 49,5Volts for the 15 cell Pylontech's .

"Lithium Battery Maintenance. We recommend that all lithium batteries and cells not-in-use go through one full maintenance cycle (charge to 100% SOC, discharge to 100% DOD, charge to 50% SOC) once every 6-12 months to maintain the battery/cell’s capacity. Please check batteries and cells in storage for voltage once every 6 months. If the cell or battery’s voltage falls below these recommendations, please charge the battery/cell to bring the voltage to the recommended voltage range."

So in practical terms keep the battery around 50-80% SOC and charge it up fully when theres loadshedding and then revert back to the lower SOC when not in use. There is no need to cycle every week.