Maypole 4A Dual Voltage 6/12V Electronic Smart Car Battery Charger Fully Automatic 5 Stage Charging Cycle Lead Acid AGM

I've been using smart-chargers for charging car batteries for nearly 15 years now, and own several of different makes, styles, and power outputs. Some are fabulous. Others aren't great. But even the worst of those in my motley collection is in my view far better than any traditional, bulky, linear car battery charger I've ever used - including Maypole's own. This Maypole 7423 is just one of several smart-chargers that Maypole also offer, and I think it's one of the better ones at the lower-cost end of the market. As with most car battery smart-chargers, it's lightweight, small, and much safer to use than a traditional charger too; it shouldn't overcharge, overheat or gas the battery, and you don't even need to disconnect the battery from the car.This Maypole 7423 seems very similar to the latest Lidl-supermarket smart-charger: It has the same 3.8 amp charge rate, it charges open or sealed lead-acid, GEL & AGM batteries, both small motorbike and larger car batteries of either 6-volts or 12-volts (from 1.2Ah - 120Ah in size, also suitable for most lawn-mower, jet-ski, van, and even caravan and motor-home leisure batteries too), it has a 14.8-volt charging option for use in very cold-weather or for charging AGM start-stop batteries, they even share similarly sized IP65 "water-splash-proof" sealed-plastic casings for outdoor use, and very useful LCD displays to show you exactly what's going on (the voltage/current display is a particularly useful and not-that-common feature on a smart-charger at this low price)! Both chargers claim to be "spark-proof", reverse polarity protected and also offer a "desulphation" mode for recovering neglected batteries (although in reality this later feature has limited value - see below). Once a battery is fully charged, it's then automatically switched into "maintenance mode", only topping up the battery with low-level current when it's needed so that you can - if you need to - leave the charger connected for months on end without worry. That's the good stuff.Perhaps for some the less-good news is that this Maypole 7423 (or the Lidl or any number of other dual-voltage smart-chargers for that matter) won't charge a 12-volt car battery if its voltage has fallen much below 8-volts, so if a car battery charger is something you only reach for when your battery is so desperately flat that the starter motor won't even turn, this probably is NOT the best choice of charger for you. The reason for this "limitation" is simply that the charger needs to determine whether the battery being charged is 6 or 12 volts, and as a 12-volt battery is already considered flat when it's fallen below 10½ volts, this 8-volt level seems a reasonable mid-point. Rather than being a hindrance though, this automatic voltage selection is in fact particularly valuable when the charger is being used for maintaining batteries in motorbikes, cars, caravans or motorhomes in long-term storage, as if the mains supply should be interrupted, this charger will automatically re-select the correct voltage and re-start (not all chargers do!) and thus continue to correctly maintain the battery. Some 12-volt only smart-chargers will recover a very flat battery from lower voltages, some from as little as 1 or 2 volts, but these obviously omit the ability to also charge 6-volt batteries, and most cost a lot more too. However, this necessary auto-voltage selection feature may not necessarily be a problem for those with batteries below this minimum level: A healthy battery that's just been temporarily drained (eg. headlights or interior light being left on) will often "bounce back" once that load has been switched off; otherwise, the trick that sometimes (but not always) works is to charge your 12-volt battery in 6-volt mode first (voltage will rise to over 7-volts), then switch into 12-volt charging mode. In other cases, a jump-start from another vehicle or power-source might be needed if your battery is in particularly bad shape, just to get a little juice into it so that smart-charging can then begin. But when a replacement car battery can today often cost the thick-end of £100 (I've just bought two at £140 each), it does seem to me to make a lot of financial sense to try extend the life of your existing battery simply by keeping it at or over the accepted 12.4 volt level - which avoids life-shortening sulphation forming and stratifying the acid: Where that's possible, this "8-volt" limitation won't matter a jot, and this Maypole 7423 again makes an ideal choice for this purpose.But why would you pay around £25 for this Maypole 7423 smart-charger, especially when the Lidl with almost identical style, power and features (and this same minor "minimum voltage" limitation) costs just £14?This Maypole 7423 uses a constant current/constant voltage "IUoU" charging algorithm which is generally acknowledged as being superior: It's faster, more efficient, and gives a more highly optimised battery - which the Lidl smart-charger (and a host of other brands) with their lesser "III" saw-tooth algorithms won't do. It's a charging profile that's often reserved for premium-brand smart-chargers much more costly than this (Ctek and Optimate spring to mind). There're other things Maypole aren't making too obvious either: Maypole state just a very simple 3-stage charging sequence is employed, but in most other manufacturers language this charging sequence would be acclaimed as a far more impressive-sounding and quite genuine 5-stage. In 12-volt car-battery charge mode, the charging sequence is:Pre-charge Battery Test: Determines if the battery being charged is 6-volt (if below 7½ volts) or 12 volt (at/above 7½ volts).Step 1): Desulphation: Sulphate is by far the most common reason why batteries fail prematurely; it begins to form internally when the battery is left undercharged (below 12.4 volts), and progressively reduces the battery's ability to accept and hold charge. This Maypole 7423 gives a 0.8A pulsed recovery charge to help "shake off" light sulphate, but this step is only applied when a 12-volt battery is between 7½-10½ volts (1½-5 volts in 6-volt mode). Common with all smart-chargers that employ this technique (including Ctek), it likely won't offer much if any improvement if your battery has been left undercharged for such long periods that the sulphate has become thick and hardened (crystalised). In all cases, I've found frequency-based desulphators (example here) are far more adept at recovering even heavily sulphated batteries, but success still cannot be guaranteed.Step 2): Bulk Charge: Full charging current is applied until voltage reaches 14.4 volts (optimum). This is where most of the energy is restored.Step 3): Absorption: Voltage is maintained at 14.4 volts, but the current (amps) is then continuously and progressively reduced until full battery capacity is achieved. This gentle "topping-up" method optimises performance whilst avoiding damage (gassing and overheating).Step 4): Analysis: Charging is stopped when the current has tapered to 1-amp, and the battery is monitored for 1 minute to ensure charge is being held.Step 5): Maintenance charging: The battery is monitored and topped up whenever the voltage drops (below 12.9 volts), again using a constant voltage (13.2 volts), variable current approach (0.1-0.8 amps). This allows the battery to be left permanently connected and well maintained in a fully-charged condition, compensating for both natural discharge and parasitic losses (alarm, clock, memory chips etc).If any faults are detected throughout the charging cycle (for example, the battery is too sulphated or damaged to be recovered or the battery isn't holding its charge), charging is stopped and a fault indicated on the display. This doesn't preclude the possibility of appearing to successfully charge a battery to then find it might be failing for any number of other reasons (although to be fair, this is common with all chargers of all types).Disappointingly, Maypole don't offer their own range of "add-on" extension leads and accessories commonly found with some other brands of smart chargers, but the later versions of this Maypole 7423 do include an interchangable direct-to-battery ring connector lead as well as a decent set of fully insulated battery-post clamps (usefully extending the output lead to about 1.8-meters) by way of commonly available SAE-standard connectors. Earlier versions carrying this same Maypole 7423 model number apparently didn't include the ring-connector lead option instead being supplied only with fixed battery clamps. Maypole call this interchangable lead an "Auxilary lead", and I'm guessing that Amazon's own suffix of "A" is in the title to help differentiate this listing of newer stock (as they have similarly done before). My own Amazon-bought example was newer stock and did include this "free" additional lead; it costs around £7 if bought separately. As Maypole confusingly call both older and newer variants model 7423, and as both are/were sold in near-identical packaging you may want to check with re-sellers other than Amazon themselves if this Auxilary lead (and therefore the ability to use 3rd-party SAE-standard extension cables and accessories) is important to you. I've added a "Customer Image" of the box to show the subtle differences in the new packaging: Note especially the ring terminals shown alongside the battery clamps on the box; the older 7423 box does not show these.If I were to be overly critical: Despite the "spark-free" claim, with some abuse (by deliberately not following the instructions) I did find it possible to generate some minor sparking (not uncommon). I also found the LCD voltage display did sometimes show some small error of up to 0.2-volts measured against several calibrated/ professional voltmeters - but that's not so far out that it really matters. Given that many premium smart-chargers (even those costing 4 or 5 times this price) don't even include a voltmeter display, for those without any voltmeter in their tool-box this feature is a valuable addition.If you need/want a combined 6/12-volt charger and don't mind the necessary "limitation" of these designs, balancing cost against specification, performance, quality and features, I think this Maypole 7423 is excellent value. It may look like a few other cheaper smart-chargers on the market, but its technical functionality is in my view very much better than most of the others I've tried: It performs equally well as (and uses a very similar charging algorithm to) similarly sized yet significantly-more-expensive market-leading models (of which I also own several). Personally, I think it's great to find - at last, and at this relatively low-cost - a smart-charger that employs a "proper" battery charging algorithm, which with regular use can usefully extend the life of your costly car or leisure battery by several years. Quite why Maypole have decided to hide this technical brilliance with an understated published specification I don't know; for it's size and ability, this Maypole 7423 delivers a more quickly charged and more highly optimised battery than virtually all other dual-voltage smart-chargers I either own or have yet tried, although admittedly I haven't tried them all. One of the few others I would also regard as perhaps worthy of consideration at a similarly low "entry-level" price is the German Absaar ATEK4000, which I have also reviewed.Pitched against the competition, I think this is a lot of smart-charger for comparatively little money: Provided the few minor issues I've outlined don't pose a handicap to how you personally intend to use this product, this Maypole 7423 is in my view certainly worthy of the full 5-stars.UPDATE May 2015: Since writing my review, a few users have reported some failures/reliability issues. I can report that my own Maypole 7423 has been in long-term use alongside several other brands of smart-chargers for some time now (including the latest, far more expensive award winning Ctek MXS 5.0, also reviewed, which ironically has now failed after 14 months use). To-date, my Maypole has clocked up many thousands of hours of constant use. It continues to perform faultlessly.

Excellent and easy to use -good price too

I already own a CTEK MXS 5.0 trickle charger, which I use on my wife's vehicle. After my 318D AGM battery gave up the ghost decently- due to lack of use during the pandemic as I work from home - and was replaced, I started shopping around for a cheaper trickle charger. The CTEK is excellent, but at around £60 I couldn't afford another one.I came cross this MayPole charger quite by accident, saw the good reviews and decided to give it a go.On opening the package, I was very impressed with the unit itself as well as the manual which was in very clear English. The unit looked and felt like a high quality product. The clear backlit display with the digital display of the charging voltage is a welcome feature (the CTEK has only LEDs). The unit comes with both crocodile clip and ring terminals (if you want a semi-permanent solution), and connects to the lead from the unit via a standard SAE connector (again a welcome change from the CTEK which uses it's own proprietary connector). I plugged it in, and given my AGM battery was relatively well charged to start with, it started charging at 'Stage 2' and within a few hours transitioned to the 'Stage 3' or float phase, with a float voltage of 13.8V being maintained consistently throughout (exactly as recommended for float charging of 6-cell AGM batteries). It's been rock solid since I plugged it in a week ago. I really don't see a difference between this MayPole and the CTEK chargers, except this one is about a third in price.Highly recommended. I wish I had come across this before I bought my CTEK. On another note, don't let your AGM battery lose charge - as they say it's next to impossible to recover these batteries once they've lost their charge beyond a certain threshold.

The charger itself is well-built, comes with clear instructions and the correct connections. A ring connector to add to motorcycles and clamps for cars.Additionally, the digital read out is helpful is displaying the status, voltage and charging state.My one criticism, as echoed by others, is that on low battery voltages (i.e. below 7v) the charger won't revive the battery back up to 12v. I have had other chargers that will do this, so it's a bit disappointing and the only criticism that I would direct to the product. As a result one needs to jump start the vehicle first, allow it to charge, and only then use the trickle charger.Other than that one minor flaw, its been great so far and I'm satisfied with it.