At RenewSolar we tend to put things to the test before making them available to clients and this can mean that we waste money but now and then we come across gems, The idea or ethic behind our business is to find the best value, they are suitable and quality levels are met. At the lowest Price.
Following 4 months of testing….
With some of the items we sell, due to no margin, we rely on the customer services of the supplier to remedy issues. for our clients, whom have the sales of good act and consumer rights, the law applies to us as it would any one else as “sellers”. Therefore the “full test” is not just the product but also the supplier and their commitment to their product.
The battery pack is a simple format of a “truck battery” no fancy wall mount or rack mount enclosure. This clearly lowers the manufacturing costs and it will appeal depending on where your installing the battery.
I haven’t understood why the cost of battery cases has been so high, after-all a rack mount is little more than a 4U server case with slightly different front and back plates.
This Draw is only £70
We happen to know the price of all the parts which would be needed to convert this draw into a battery. so the £400+ price tag, is way way off the mark, even with a JK BMS V2….
We know that the battery meter we are using is “off a little” and is just cheap tooling that you can buy online ( we have a youtube video on making it) We found that the AH rating was low, but more or less consistent. the more or less part of this is the fact that we have to account for temperature at the cell level. This accounts for around 3ah per cell, that’s 8 cells and 24ah.
This means that you would expect a capacity rating from 76 ah but you also have to account the “safety” and “performance” settings within the BMS.
For users, you would look differently at the product than the manufacture and the myths of LFP are quite … funny.. but for the most part if you make a battery you can make 5000 cycle claims when you “reserve” the battery. in other words SOC and DOD is 10% on each end, thus lowering the capacity by 20%, or that’s 20ah in terms of a 100ah battery. its fair to say that from 100ah you would get 80 ah, but they use slightly larger cells, therefore you are likely to see a capacity range from 95ah +- 10ah.
So the battery meter we used gave us results and so we had to check these out, we knew the current and the voltage as well as the time, and as you can see above, the battery comes in on capacity (100ah).
The battery has both over-voltage and under-voltage protection mechanisms in place. However, the low voltage cut-off is set at a relatively high level of 24.8 volts. Some users have expressed dissatisfaction with this setting, as they believe it should be lower. Ideally, they would have preferred a cut-off around 23 volts (equivalent to a 2.875-volt cell) or even 22 volts (equivalent to a 2.75-volt cell). The challenge lies in finding the right balance: while a lower cut-off could increase capacity, it might impact the battery’s overall lifespan due to more frequent cycles, however the available capacity is very small under the set voltage. The cycle gains of course are shown in the chart above.
By preventing deep discharges, you can significantly extend the battery’s life, as discussed in our other posts. Interestingly, your team didn’t dismantle the battery to access the low-temperature sensor, as you have additional hardware to monitor cold conditions and core temperature. Furthermore, the short-circuit tests only affect the Battery Management System (BMS) or blow a fuse, and you’ve already installed breakers on the circuit—a practice that most people should adopt.
In summary, finding the optimal low voltage cut-off for battery protection involves balancing capacity and cycle life, and your team’s approach seems well-considered
Pricing
The ULTRAMAX is priced at £892 its a well known brand, from lead acid batteries,
The Eco Worthy is priced at £499, these tend to be budget and work, but has some limits.
The Victron is around £1,400
The Renology is priced at £639
The Roamer 24-100XTREME comes in at a whopping £1,800
Our little offering comes in at £350.00
There is a catch, the delivery times on these are lousy. they are supposed to be improving this, but this only occurred recently. This would bring delays to about 7-10 days.
Here are some details
2kWh usable battery.
25.6v (24v)
Can be stacked (4P) maximum. (400Ah).
There are 200Ah Batteries also available, but not tested by us with 12, 24, and 48v.
Dimensions:
24.5 x 64 x 22cm
Weight 20kg
Cell – New A grade, Gotion
Cont. dis 100a
4000~6000 cycles. 4000 Time Cycles at 100% DOD, 6000 Time Cycles at 80% DOD.
Single battery suitable for 2540W inverter, recommended <1200W
Head over the shop to make your order your 24v Lifepo4 Battery.
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