Question: Cyberpower CP1000AVRLCD UPS, voltage, battery up-size (hack), runtime
Question: Cyberpower CP1000AVRLCD UPS, voltage, battery up-size (hack), runtime
I'm tired of constantly swapping the small UPS batteries in my three Cyberpower UPS models. I recently replaced one in the CP1000AVRLCD with a 35ah AGM Deep cycle, and it now lasts around 90 minutes (possibly longer). However, this experience made me reconsider some details and I'm still unsure.
Before and after the swap, the Cyberpower Software Powerpanel for Business displays the battery at 20v. It's a 12v unit, which should read about 13v ±. This is unrelated to my change.
Is the software unreliable? Could there be a buck converter in front of the inverter that's boosting the voltage and then measuring it?
After installing the larger battery, I performed a test (see below). It ran nearly 90 minutes but then triggered the unusual error "not completed, the battery runtime is insufficient." After all that time.
My suspicion is that the firmware or software is hard-coded to work with small batteries, providing misleading data. Since it's recharging, the percentages might be incorrect, and the 8-minute runtime seems unrealistic.
Has anyone else modified Cyberpower UPS units with bigger batteries? Are there any solutions to fix the estimates so I don<|pad|>'s get accurate readings and avoid false alarms when discharge starts? I've just turned off the shutdown of the PC, but it's possible it might also shut down the UPS output incorrectly.
Has anyone else modified Cyberpower UPS units using bigger batteries? A basic search on the web brought me to this Reddit post. There are also videos on YouTube showing people altering their UPS systems, though I’d be cautious about trusting those sources.
It's challenging to accurately gauge the charge in a battery without testing it under specific conditions. It would be helpful if there were a method to monitor it, as an old battery might appear normal but suddenly lose voltage when used. It seems there might be some software limitations they implemented for calculations. Changing these would likely require significant effort and technical expertise. Most UPS systems don't allow firmware updates, making it difficult to modify the software and repair the flash chip. Generally, the USP will function properly even if it provides incorrect readings; batteries usually shut down when voltages drop too low, regardless of reported values.
It's not advisable to use large batteries in these units because the components are designed for limited duty cycles. The charging and inverter circuits are only meant to operate continuously without interruption, which could affect their lifespan. Running them longer than intended may shorten the life of the UPS electronics.
If you're serious about this, consider purchasing an online or double conversion UPS, which uses components built for continuous operation. These are usually more costly, but building your own with solar-compatible parts can be a cost-effective solution, particularly when using larger batteries.
I'm observing the recharge process. It's quite slow, yet it's progressing steadily and at the moment it isn't overheating. Although the lifespan might be affected, aside from regular battery swaps, it remains affordable if it stops working. The overheating concern seems higher during discharge phases (though I hadn't checked that earlier), but the fan helps somewhat. That's why I increased the current from 9 to 35ah, aiming closer to around 30. I wasn't certain it would provide enough power for a deeper discharge, like charging an old car battery. So far everything seems fine.
My main aim now is to locate a suitable charger/inverter and set up a DIY UPS for this room and another space nearby. The biggest challenge is finding a monitorable device—most units have complex interfaces or are only accessible via remote controls or panels, lacking network monitoring options (except for smaller units under 2kw).
Overall, this approach is working well without significant financial risk. A single deep discharge or recharge cycle will help determine if overheating is a real issue. I usually replace the unit after 2–3 battery changes, so this one from 2018 fits that timeline.
Just in case it holds value for someone later, here are some notes (this isn’t really useful data, so feel free to skip if you’re not interested).
I examined the State of Charge shown by the UPS during the battery charging process. It displayed an unusual step function, which I initially thought might be linked to voltage measurements rather than coulomb counting. However, the voltage readings were relatively smooth rather than abrupt, and it never reached the pre-swap level.
When I checked the no-load voltage of the failing battery, it was 13.3 volts, while the AGM unit read 13.0 volts. The difference seems reasonable for a 12V (class) battery, though I’m still puzzled about why it displays such high voltages for a standard 12V unit.
It appears the SOC algorithm likely isn’t a straightforward function—it probably uses a table with significant gaps or incorporates time as a variable.
Still, 13.0 volts is a solid indicator of a fully charged AGM battery. If I lowered the lower threshold, the reading would be around 11.2 volts, which is still within the typical 10% range.
The recharge cycle lasted approximately 22 hours. I was concerned it might take days, but for comparison, a 15kw Cyberpower unit with stock batteries required only 12 hours to fully discharge. This was longer than expected, though the charging time wasn’t excessively long.
Notably, there were no abrupt changes in voltage like in other units of similar age and type—just a gradual progression. This makes me suspect the step function might depend on time rather than just voltage.
So far, this setup seems reasonably effective, especially compared to other units that fail sooner. I’m planning to order two 30Ah batteries for this model when the others fail.