CTEK CT5 Powersport review | Lead acid and lithium charger tested

CTEK CT5 Powersport review_06


Date reviewed: June 2023 | Tested by: John Milbank | Price: Around £90 | www.ctek.com/uk


The CTEK CT5 Powersport on review here is simple to use, gives you all the indications of what it’s doing that you really need, and could get you out of trouble when things go wrong. I’ve been using it on the lead acid battery of my 2001 VFR800 for the past month, as well as the lithium battery installed in my 1999 Kawasaki ZX-6R, as well as on two test batteries to see if it’s worth the money…


Pros & Cons

  • Very simple interface
  • Works across lead-acid and lithium batteries
  • Effective with my damaged battery
  • ‘Recovery’ mode not relevant for many bike batteries
  • Supplied fly-lead a bit short for some
  • No support for older 6V batteries
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CTEK CT5 Powersport features

The CTEK CT5 Powersport keeps things simple with an uncluttered cover plate featuring eight easy-to-understand LEDs. For the average motorcyclist, it does everything you’d need…

  • Supports all lead-acid batteries (AGM, Wet, Gel, EFB, Ca/Ca, MF)
  • Charges lithium batteries (LiFePO4, Li-Fe, LFP)
  • Auto reverse polarity protection
  • Up to eight step charge cycle
  • Designed for 5-25Ah batteries
  • Includes a proper, printed and useful instruction manual
  • Minimum battery voltage to start charge: 2.0V lead acid, 5.0V lithium
  • Recovery mode (Wet batteries only)
  • Charging voltage: 14.4V lead acid, 15.8V recovery, 14.2V lithium
  • Back current drain claimed to be under 1.5A/month
  • Ripple claimed to be under 4%
  • 0.3A mains draw during peak full charge cycle
  • Five year warranty

‘Back current drain’ is how much current the charger takes from the battery if the mains supply is disconnected, while ‘ripple’ is a pulsing of the output due to the conversion from AC to DC, and is the quality of the charging voltage and current. CTEK says that a high current ripple can heat up the battery and have an ageing effect on the positive electrode, while a high voltage ripple could harm other equipment (like the bike’s ECU) that’s connected.


CTEK’s connectors clip together securely, and even have a sealing O-ring



The CT5 Powersport comes with a set of quality crocodile clips and a fly-lead that you can fit permanently to the bike’s battery, ready to plug into the charger.

The mains lead on this CTEK is 135cm long, the output cable is 105cm, and the unit itself is 17cm, making for a total reach of 257cm. A 2.5m output extension lead is available for around £17, which would prove useful in my garage, where the charger often needs to reach across another bike.

The crocodile clips add an additional 46cm, measured to the tips, but the supplied fly-lead is only 40cm long, which I found very tight on my ZX-6R. It’ll depend where you want the connector to sit on your bike, but it’s worth noting.

The fly-lead doesn’t include a fuse, meaning it could vulnerable if the cable did manage to wear through and short on the frame, though that is unlikely. With how it passes under the subframe on my ZX-6R, I’ll be wiring in a fuse myself.


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The supplied fly lead is a bit short for my ZX-6R


CTEK uses its own connector, rather than the SAE-type you’ll find on the current Optimates (which used to use Tamiya-style connectors in the old days). CTEK’s version is very easy to use, and offers a positive connection; it’s much smoother than the SAE version, yet still locks in place well.

The supplied fly-lead has a silicone cover that protects the terminals from damp and road filth well, though depending where you put it, can be knocked open slightly more easily if your leg rubs against it than the new cap that’s fitted to the Optimates. To be fair, there’s not a lot in it, and the CTEK version is less industrial feeling in use, if not as universal.

Note that while the CTEK connectors look similar to those used on the Telwin charger reviewed here a few years ago, the two are not compatible.




The CT5 will charge pretty much any 12V bike battery thanks to its support for both lead-acid and lithium packs between 5 and 25Ah. While not covering car battery capacities, there seems little reason the CT5 Powersport couldn’t be used to charge a car battery if needed – the 2.3A maximum charge current would be slow on the average bigger pack, but having used an old Optimate that puts out just 600mA many years ago on my car, it’ll get there in the end. The CTEK will charge at 2.6A for a maximum of 20 hours, which should equate to a maximum capacity 104Ah.

The CT5 Powersport doesn’t work with the 6V batteries found on some old bikes, but this isn’t going to be a problem for the vast majority of buyers; it’s just worth noting if you also own a classic.

While few bikes come with lithium batteries, this chemistry can have its advantages. I have a Shorai LFX18A1-BS12 Lithium Iron (Li-FE) on my 1999 Kawasaki ZX-6R – not for the weight saving over a lead-acid pack (which is substantial), but for the fact that it lasts a very long time without losing any charge when there’s no draw on it. As the Kawasaki has no electronics nibbling away at the battery, and I rarely have time to ride it, it seemed an ideal place to put the pack, which I’ve had for more than seven years now and is still going strong.


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Unusually in this day and age, the CTEK comes with a proper, printed instruction manual that’s genuinely useful. Please take note other tech manufacturers… intercom and sat-navs I’m looking at you!


CTEK CT5 Powersport performance

In normal daily use, the CTEK CT5 is very easy to use, and does its job of maintaining your bike’s battery.

It’s important to understand the difference between an old-school trickle-charger, which just constantly dribbles a current into the battery and can cause damage over the long term, and a ‘smart’ maintenance charger that constantly monitors the battery and keeps it topped up only when needed (called ‘Care’ on the CTEK).

The CT5 needs switching between lead-acid and lithium modes using the button on the front, but it does remember where it was when it was last switched off. Once connected to the battery then plugged into the mains, it runs through a cycle of programmes to keep your battery at its best:


CTEK CT5 Powersport lead-acid charge cycle








Max 4h (inc Check 2)



2.3A until 12.6V

Max 4h (inc Check 1)



Increasing voltage to 14.4V, 2.3A

Max 20h



Declining current, 14.4V




Voltage limit 12V




Only active in recondition mode

2h or 6h



13.6V, 2.3A maintenance charge

10 days



12.7V, 2.3A – 14.4V 1.0A

Max 1h pulse every 24h


Stage 1: Desulphation. This is used to remove lead sulphate crystals on the plates, which can cause a battery to have a significantly reduced charge. By pulsing the voltage and current, the charger attempts to ‘shock’ the sulphate from the plates and restore capacity.

Stage 2: Soft start. This is a test of whether the battery can accept a charge – if it fails, the charger will stop.

Stage 3: Bulk. This is where 80% of the battery’s capacity is restored, using the maximum current and voltage.

Stage 4: Absorption. The current is gradually decreased until the battery’s totally full.

Stage 5: Analyse. The battery’s monitored to see if it can hold a charge. If not, it likely needs replacing.

Stage 6: Recondition. This must ONLY be used for ‘Wet’ batteries, so as most motorcycles use AGM lead-acid, it’s not really relevant. It only becomes active if you press the button and select the ‘recond’ mode, and outputs 15.8V at 0.9A. This also must not be used on lithium batteries.

Stage 7: Float. A constant charge is maintained to keep the battery full.

Stage 8: Pulse. The final stage, and rather than just keeping the Float charge going, the CTEK CT5 Powersport keeps the battery’s capacity at 95-100% by giving a maximum of a one hour pulse every 24 hours.


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It’s very hard to test a manufacturer’s claims that its charger can ‘recover’ a worn battery as I’ve still not come up with a way to have consistently damaged packs to compare. However, I did have an old PRX9-BS bike battery that I’d taken out of my ZX-6R due to it not holding a charge anymore.

My 20+ year-old Optimate would charge this battery, but the pack wouldn’t last very long at all. I’d charged the battery many times with this charger, and was sure the pack was well past its best. When I first connected the CTEK to it, it showed a full charge very quickly, making me suspicious that the CT5 was declaring the cheap, knackered battery as good to go, when I knew it wasn’t.

After charging with the (very old) Optimate, I discharged the battery using a 60W halogen headlight bulb while monitoring the voltage with a multimeter. After that, I charged it using the CTEK CT5 Powersport and tested it again… clearly the low voltage of the pack triggered a successful desulphation. Given the surprising results of monitoring the voltage while discharging with the bulb below, I charged it for a second time with the CTEK and ran the test again…



Old Optimate

CT5 charge 1

CT5 Charge 2

60W bulb test

Battery at 1.8V in 1.5mins

Battery at 9V in 6mins

Battery at 9V in 9.5mins


The difference in performance of the battery after charging with the CTEK the second time, compared to many charges on my old charger was shocking – at first the battery would drop well below the typical minimum charge of a lead-acid battery in a few seconds while connected to the bulb, but after two charges with the CT5 it was still at 12.31V after six minutes. At seven minutes, it dropped from 12.1V to 10.25V, then slowly reduced to 9V by the time I stopped the test. Taking the bulb off, the battery recovered to an indicated 12.85V. I’d also left the battery for several days after the second charge on the CTEK and my meter showed it still sitting happily at 13.2V before running the bulb test.

It is important to note that this was a very old Optimate I was comparing the CTEK to, as I don’t have a modern one to try it against. I also don’t know whether the desulphation mode of the old Optimate had been triggered as the battery hadn’t been fully discharged, so this can’t be considered a comparison of technologies, only a confirmation that the CTEK’s desulphation mode does work. My testing indicated that the CTEK didn’t ‘know’ the old battery was heavily sulphated until it got a chance to try charging it from a very low voltage, at which point the mode kicked in.

Of course, how long a previously worn-out battery can last after being recovered is difficult to say, so the best thing is to prevent them getting into this state in the first place by keeping them topped up.


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Charging a lithium battery requires a different program as it must NOT be over charged, so the initial desulphation mode must NOT be run. They also have different peak and minimum voltages…


CTEK CT5 Powersport lithium charge cycle








5 mins



Max 14.2V, 1.0A

30 mins



Max 14.2V, 2.3A




Max 14.2V




Voltage limit 12V




Max 13.3V, 2.3A

10 days



Max 13.8V, 2.3A

Max 1h pulse every 10 days


Stage 1: Wake up. Some lithium batteries have Under Voltage Protection (UVP) that stops them getting deep-discharged, which can destroy them. The wake-up stage is designed to get past this automatically, though if it fails and the power LED starts flashing, holding the mode button for 10 seconds will activate manual wake-up mode. If this fails, try again with the battery disconnected from the bike, but if it still won’t work it’s likely the battery needs replacing.

Stage 2: Accept. This mode tests whether the battery can safely accept a charge, and will stop if it finds it can’t.

Stage 3: Bulk. Maximum current is used to charge the battery to 90% capacity

Stage 4: Absorption. A declining current brings the battery to 100%.

Stage 5: Analyse. The charger tests whether a charge is being held.

Stage 6: Float. The battery’s voltage is maintained with a constant charge.

Stage 7: Pulse. This keeps the battery at 95-100% capacity, monitoring the voltage and giving a pulse to keep it at full charge.


During my testing, the CTEK CT5 Powersport took my Shorai lithium battery to a measured 13.42V by the time it entered the ‘Care’ mode. I have Shorai’s own charger, which takes the pack to an indicated 13.36V in ‘storage’ mode, which is 80% full capacity. A ‘full’ charge will take it higher, but this can reduce the battery’s life and is usually unnecessary as a lithium pack will typically crank an engine over strongly (assuming it’s not in a cold ambient temperature) below 60%. Lithium batteries drop off suddenly in performance as they reach the limits of their capacity, unlike lead-acid batteries, which tend to tail off more gradually.

Based on this, it appears that the CTEK doesn’t try to push a lithium pack to an absolute 100% capacity, which could shorten its life. Rather, it maintains it at that storage level of approximately 80%, which makes sense for something that’ll be left plugged in.

The CTEK – and any other two-wire lithium charger – will not itself be able to ‘balance’ the individual cells inside to each have the exact same voltage for maximum performance, though quality lithium batteries should include their own built-in balancer circuit – I’d suggest always looking for a built-in balancer when buying a lithium battery.


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CTEK CT5 Powersport accessories: Indicator fly-lead and bumper

One of the accessories available for the CTEK CT5 Powersport is the ‘Indicator’ fly lead, which costs around £12. This is a far more useful length of 56cm, and it includes a fuse.

Using the same smooth and reliable connector, along with the silicone cap, the ‘Indicator Eyelet’ fly lead is available with M6 or M8 eyelets (M6 will be most likely the size for motorcycle batteries), and has three LEDs that flash very briefly to show the state of charge:



Battery voltage




<12.65V > 12.4V




Given the trigger voltages for these LEDs, the CTEK Indicator Eyelets are NOT suitable for use with lithium batteries, which must not be allowed to drop below 13V (about 15% capacity).

In my testing, the CTEK Indicator fly-lead pulls just 1.27mA, peaking at around 3mA for the split second that the LED flashes. This will of course have some impact on your bike’s battery, but it’s absolutely tiny – if we estimate a 1.5mA average draw, that would take 28 days to pull just 1A from your battery. And as it’s flashing to keep you aware of the state of charge, it’s easy to know when to pop the charger on, and could prove really helpful for those with multiple bikes that don’t want multiple chargers.


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The CTEK CTX Protect bumper might seem an unnecessary accessory – and if you have the charger fitted to the wall it probably is, but besides adding some protection to the device if it’s dragged around on the floor or dropped, it helps it stay in place when rested on the bike’s tank, which I’ve found really helpful when having it draped across the garage to reach a bike. The cheapest I could find it is £10.99 at Halfords, though remember that BikeSocial members save 8% at Halfords, with many more 15% deals available through the year too.


Four alternatives to the CTEK CT5 Powersport charger

There are plenty of battery chargers available, including some at very low prices. It is hard to reliably test the claims of manufacturers, but many consider a decent brand to be a worthwhile investment knowing the cost of the delicate electronic components fitted to modern bikes. A decent one should also last a very long time…

  • The Optimate 2 Duo costs £79.90, and is also available with optional indicator fly leads. It has a 2A maximum output, and supports both lead-acid and lithium packs, with an initial desulphation mode for lead-acid batteries. Read the full review of the Optimate 2 Duo here.
  • The Optimate 1+ is now the 1 Duo, and can also charge lithium batteries. It has a 0.6A output, and retails at £52.90. Read the review of the previous Optimate 1+ here.
  • The Oxford Oximiser 3X charges at up to 3.6A and retails at £99.99, though we’ve seen it for almost half that at times. Read the review of the Oxford Oximiser 3X here.
  • The CTEK CS One is the company’s flagship charger, and it’s priced to match. But it’s heavy on features and has an 8A maximum output. We just wish it had a proper display, instead of an app to change settings. Read the full review of the CTEK CS One here.


These are just four of many alternatives – you can find all the motorcycle battery chargers we’ve tested here and be sure to regularly check for the discounts available through Bikesocial membership.