FAQ
TL;DR: In CMS’s tests the V40 pushed 1 000 mA into each slot and completed an 8-cell cycle in 10 h [Elektroda, CMS, post #17020244] “It will charge up everything that fits.” [Elektroda, CMS, post #17020244] For US $20.99 the unit delivers four 0.3–1 A channels, discharge testing, and a 5 V/1 A USB port. Why it matters: You get lab-grade functions for flashlight money.
Quick Facts
• Selectable charge currents: 0.3 / 0.5 / 0.7 / 1.0 A per slot [Elektroda, CMS, post #17020244]
• Accepted sizes: 26650 → AAA, plus 3.2–3.7 V Li-ion, Ni-MH, Ni-Cd [Elektroda, CMS, post #17020244]
• USB output: 5 V ±5 %, 1 A, works only on battery power [Elektroda, CMS, post #17020244]
• Street price (Feb 2018): US $20.99 incl. 12 V / 2 A PSU [Elektroda, CMS, post #17020244]
• Displayed metrics: slot-ID, mode, voltage, current, elapsed time, Ah, ≈45 mΩ internal-R resolution [Elektroda, CMS, #17020244; #17044224]
What chemistries and sizes can the VariCore V40 charge?
The V40 accepts Li-ion (3.6 / 3.7 V), Li-Fe, Ni-MH and Ni-Cd cells in 26650, 22650, 18650, 16340, 14500, 10440, AA, AAA, A and SC formats [Elektroda, CMS, post #17020244]
How do Charger, Fast Test and Nor Test modes differ?
Charger simply fills the cell at the selected 0.3–1 A rate. Fast Test charges, then discharges to a safe cutoff and stops, logging the discharged capacity. Nor Test charges, discharges while logging capacity, then fully re-charges the cell so you can remove it ready-to-use [Elektroda, CMS, #17020244; #17021506].
Does the V40 measure capacity during discharge or charge?
During Fast Test and Nor Test the meter integrates current during the discharge phase, not the charge phase [Elektroda, CMS, post #17020244] Ordinary charging still shows accumulated Ah, but that figure includes heat losses and is less reliable for true capacity.
How accurate are the displayed voltage and current values?
Forum cross-checks show a deviation of about ±0.01 V and ±10 mA against a handheld multimeter up to 20 V/10 A ranges [Elektroda, siewcu, post #17020469] That is well within 1 % for cell work.
Is the internal-resistance reading trustworthy?
Users report repeatable values around 45 mΩ for healthy 18650s and clear jumps on tired cells [Elektroda, CMS, #17020244; PiotrPitucha, #17044224]. Expect ±15 mΩ spread; use it for sorting, not metrology.
How does the 5 V USB output behave?
The USB port delivers 5 V ±5 % at up to 1 A, but only when the charger is unplugged and at least one Li-ion cell is fitted. It shuts off as soon as external 12 V power is applied [Elektroda, CMS, #17020244; #17021506].
Can the V40 fully charge modern Ni-MH cells like Eneloop?
Yes. Owners report termination voltages between 1.50 V and 1.55 V depending on cell impedance, matching Eneloop’s recommended ΔV profile [Elektroda, PiotrPitucha, post #17044224]
Is the included 12 V / 2 A power supply safe?
It is a switching adaptor in a sealed enclosure. No destructive teardown was done, but users suggest verifying isolation and EMI before continuous unattended use [Elektroda, mkpl, post #17023121]
Is the V40 just a rebadged LiitoKala Lii-500?
Both share slot layout and button logic, yet differ in firmware: Lii-500 logs capacity on charge, V40 on discharge [Elektroda, CMS, post #17025000] PCB photos also show distinct component selections, so call them siblings rather than twins.
What charge and discharge currents can I expect?
Charging: user-selectable 0.3, 0.5, 0.7 or 1.0 A per slot. Discharge during tests auto-selects 0.25 A for ≤500 mA setting and 0.5 A for higher settings [Elektroda, CMS, post #17020244]
How do I run an overnight capacity test safely?
- Insert cells and tap MODE until “Nor Test” appears.
- Tap CURRENT per slot to pick 0.5 A to limit heat.
- Walk away; the V40 will charge, discharge, record mAh, then recharge to full. The display freezes the measured result for later reading [Elektroda, CMS, post #17020244]
When can the V40 give misleading data?
Very old cells can show double their real capacity because heat losses during the follow-up charge inflate the displayed Ah value [Elektroda, CMS, post #17051128] "A miracle or something," the reviewer quipped [Elektroda, CMS, post #17051128]
How much does the unit cost today?
CMS paid US $20.99 including the PSU in early 2018 [Elektroda, CMS, post #17020244] Market checks in 2025 place new stock between US $22 and $28 shipped, still the lowest tier for four-slot analyzers (AliExpress listings, 2025).
What if I find the slots too tight to remove cells?
The shell lacks finger recesses. Use the spring-loaded tab: pull it back with a fingernail, then tilt the cell up from the negative end. Users confirm this “spring-back” method avoids torn thumbnails and fabric snags [Elektroda, PiotrPitucha, post #17021401]
Can I use the PowerBank feature while the charger is on mains?
No. The firmware disables the 5 V rail whenever 12 V input is present, so simultaneous wall-power and USB-out is impossible by design [Elektroda, CMS, post #17021506]
