There's a reason every decent independent garage has a row of CTEK chargers hanging on the wall. They don't cook batteries, they don't quit on a deeply discharged AGM, and they keep modern stop-start electrical systems alive while you're swapping a battery. After 32 years of charging everything from MGB 6-volts to 24V plant batteries, this is the line-up that earns its money.
A cheap trickle charger has one mode: dumb constant voltage. Leave one on a healthy battery for a week and you'll boil the electrolyte off; leave it on a deeply discharged AGM and it'll never wake up. CTEK chargers run an 8-step automatic programme — desulphation, soft-start, bulk, absorption, analysis, recondition, float and pulse maintenance. That's the difference between a battery that lasts five years and one you're replacing every two.
MXS 5.0 covers the everyday car-and-van bracket (1.2–110Ah). MXS 10 steps up for bigger 4x4, van and motorhome batteries (8–225Ah) and recovers them faster. The PRO25S is the workshop unit — 25A output, full supply mode for diagnostics, parallel charging. For a classic with a 6V battery, the MXS 5.0 covers both 6V and 12V at the flick of a switch.
Modern stop-start cars run AGM or EFB batteries — they need a slightly higher absorption voltage than flooded lead-acid, and a wrong charger will undercharge them for years until they fail prematurely. Every CTEK from MXS 5.0 upwards has a dedicated AGM mode. Lithium support (LiFePO4) is on the Lithium XS and PRO25S — don't put a lithium battery on a charger without it.
Disconnect a battery on a 2015+ car and you lose radio codes, sat-nav presets, sometimes throttle adaptations. Supply mode on the MXS 10 and PRO25S puts a steady 13.6V across the car's electrical system while you physically swap the battery — no lost settings, no relearns. We use it daily.
Recond pulses higher voltage at a sulphated battery to break crystal build-up. It works on tired flooded batteries that have been left flat. It can also kill a healthy AGM if used carelessly. Rule of thumb: only use recond once, on a battery that's measurably weak. If it doesn't come back, it's done.
Yes — every CTEK from MXS 5.0 up has a pulse-maintenance final stage designed for indefinite connection. Ideal for classics, motorhomes or seasonally stored cars.
Not if you select AGM mode — it adjusts absorption voltage for the higher charge acceptance these batteries need. Using standard mode long-term will undercharge them.
Either works, but the MXS 10 will recover a discharged battery in half the time and gives you supply mode for battery swaps. If it's a daily-use van, the MXS 10 pays back fast.
Bob's Mechanical Repairs — independent family-run garage in Birnam, Dunkeld, Perthshire. Call 01350 727 276 or email [email protected].