Halfords Smart Chargers For Lithium Batteries

You shouldn't need to trickle charge a lithium battery really...

 

I'd recommend a Noco. As it can charge all Lithium and or normal wet cell batteries and is a good price on amazon right now.

https://www.amazon.co.uk/gp/product/B0828HGG2Q/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

 

I agree with this - a Lithium battery retains charge for far longer than a traditional lead acid battery and the technology is very different.

They only thing you have to be wary of is if the bike is drawing power over the winter for an alarm then it could drain the battery right down - and a completely drained Lithium is scrap.

The simplest thing to do is take the battery off the bike and store it indoors over the winter if the Garage is unheated and not insulated - keeping the battery from getting too cold will prolong it’s life.

Sat on the shelf with no power draw inside it can happily be left for 6 months without charging.

The first time you start the bike with it you may have to wake it up by turning on the ignition and drawing a little power but after that it should start fine and the first run out will charge it back fully.

Constant trickle charging isn’t good for them so I would be interested to know how these Lithium battery tenders operate.

 

Can’t provide an opinion on the Halfords charger but would definitely recommend Noco chargers - I use one on my lithium battery in my Multi V4S and is very simple to use…Is a must if you have a tracker fitted and bike is not used quite as much over winter.

 

What about periodic top ups using a trickle charger? Like your alternator does when you ride it?

 

Modern Lithium bike batteries have a built in Battery Management System - unlike a lead acid battery - the BMS is in control of looking after the battery and it’s quite happy to be charged periodically and left.

So - yes periodic charging is a viable option - as long as the charger is within certain parameters.

An ideal charger wouldn’t constantly try to monitor the battery and look after it like a lead acid battery maintainer would. It would just turn on every so often and feed the BMS in the battery the appropriate current to do it’s thing.

That’s why ‘trickle charging’ isn’t really the appropriate term for Lithium.

There’s loads of detailed info out there about looking after Lithium but this is a nice short guide covering the main points:

https://fulbat.com/wp-content/uploads/2021/07/2021-07-FULBAT_EN_Guidelines_Lithium_PDF.pdf

 

I find this interesting and just read the information on the link. I have used an Optimate 4 trickle charger on my previous two bikes, a 2016 Monster 821 & a 2017 R1200GS, both with lithium batteries. I was away for 6 weeks periods and always connected the charger before leaving and I didn't have any issues at all with either battery. I still use it now on my new MTS V4S as my garage has no insulation and so is very cold. Admittedly I've only used twice so far and have disconnected it after about 30 minutes when it shows fully charged. Ducati actually have a trickle charger which they recommend for all new bikes, so what's right & what's not? I certainly don't know, but as mentioned my experience using a trickle charger has been fine.

 

I’ve had my 2016 Panigale connected to a CTEK lithium charger since new, 24/7 with no issues to date

 

I have mine all on Optimates. All have Li batteries. All good.

 

I think it very much depends on how good the Battery Management System in the Lithium is as to how much you can get away with.

The Optimate 4 comes with this warning from the manufacturer:

“Can my OptiMate be used with Lithium / Lithium-Iron / LiFePO4 Batteries?
We only recommend OptiMate Lithium chargers for Lithium batteries. These batteries are very different to lead-acid construction and have very different characteristics. OptiMate Lithium chargers have many special functions and features designed solely for Lithium batteries. Using an OptiMate Lithium charger will extend the life of your Lithium battery enormously. In certain circumstances, using a traditional lead-acid charger will cause damage to a Lithium battery hence we cannot recommend it.”

As long as it’s getting the right voltage then a good BMS it will do it’s job to look after the battery. Some of them have safety systems in them to protect the battery from abuse - so using a trickle charger won’t immediately kill it but it is likely to shorten the life of the battery.
A well cared for Lithium battery should last 10 years - so it’s very likely that you won’t know if a trickle charger has caused any damage for some time. - even if you knock 2 years off the life - you won’t know until 8 years have passed.

Below is a more detailed explanation of why manufacturers warn not to use a lead acid battery maintainer on Lithium.

“Can I charge my lithium battery with a lead acid charger?

This is a question we get asked every day by the general public. Lithium batteries are not like lead acid and not all battery chargers are the same.

A 12v lithium LiFePO4 battery fully charged to 100% will hold voltage around 13.3-13.4v. Its lead acid cousin will be approx 12.6-12.7v. A lithium battery at 20% capacity will hold voltage around 13V, its lead acid cousin will be approx 11.8v at the same capacity. As you can see, we are playing with a very narrow window of voltage with lithium, less than 0.5V over 80% capacity.

A Lithium LiFePO4 charger is a voltage-limiting device that has similarities to the lead acid system. The differences with Li-ion relate to the higher voltage per cell, tighter voltage tolerances and the absence of trickle or float charge at full charge. Whilst lead acid offers some flexibility in terms of voltage cut off, manufacturers of LiFePO4 cells are very strict on the correct setting because Li-ion cannot accept overcharge. The so-called ‘miracle charger’ that promises to prolong battery life and gain extra capacity with pulses and other gimmicks simply does not exist. LiFePO4 is a “clean” system and only takes what it can absorb.

Lithium chargers are based on a CV/CC (constant voltage/constant current) charge algorithm. The charger limits the amount of current to a pre-set level until the battery reaches a pre-set voltage level. The current then reduces as the battery becomes fully charged. This system allows fast charging without the risk of over-charging and is suitable for Li-ion and other battery types.


Lithium Charger Algorithm

As you can see from the above charge graph, the lithium battery has a steep rise in voltage at the very end of the charge cycle. At this stage the charge current drops extremely quickly and the charger then switches to power supply mode.

The majority of the lead acid smart chargers these days have specific charge algorithms to suit Flooded/AGM/Gel batteries which generally require a 3 stage charge process, Bulk/Absorption/Float. Once the charger enters the bulk state, it will normally charge a lead acid battery at full current to approx 80% capacity. At this point the charger will transition to the Absorption stage.



Typical Lead Acid Charger Algorithm

In this charge phase the charger will hold the maximum voltage for the chosen battery and charge the battery with reduced current as the batteries internal resistance can’t accept the charge current at maximum output. Once the current reduces to approx ≤10 % of the chargers total output, it will then move to the float state. The absorption stage is also time based, if the charger is still in its absorption phase after 4 hours, the charger will automatically transition to the float stage. This generally happens if the charger is undersized for the battery bank or there are loads running on the system and not allowing the charger to reduce the current below the transition point.

Most, if not all, lead acid chargers have an equalization mode. On some chargers this mode may be automatic and can’t be turned off. Lithium batteries do not require any form of equalization. Applying an equalization charge of 15v+ to a lithium battery will damage the cells beyond repair.

The other function that lead acid chargers have is a “return to bulk” voltage. A 100% full lead acid battery’s voltage is approx 12.7v. Once the charger is in Float, it will maintain the battery at a pre-set voltage (normally between 13.3-13.8v subject to the battery type) and also support any loads running at the time. If the loads increase past the charger’s maximum output in float, then the battery voltage will start to reduce. Once the voltage reaches the “return to bulk” voltage, the charger will then start a new charge cycle and start re-charging the battery.

The “return to bulk” voltage setting in lead acid chargers is normally 12.5-12.7v. This voltage for a lithium battery is way too low. At this voltage the lithium battery will have been depleted to approx 10-15% state of charge. Lithium charge algorithms will normally set a return to bulk voltage of 13.1-13.2V. Just another reason that a standard lead acid charger doesn’t suit lithium batteries.

Some lead acid chargers “ping” the battery on startup to determine the voltage/resistance of the battery. Based on return information, the charger then determines what charge phase to start in. Because lithium will hold voltage above 13+v, some lead acid chargers will see this as a near full battery and enter into a float stage and bypass the charge stage all together.

You can use a lead acid charger on a lithium battery if you want, HOWEVER, you must NOT use a lead-acid charger if it has an automatic “equalisation mode” which cannot be permanently turned off. A lead-acid charger that can be set to charge no higher than 14.6v can be used for regular charging and then MUST be disconnected after the battery is fully charged. DO NOT leave the lead-acid charger connected to maintain or store the battery, because most will NOT maintain the proper voltage charge algorithm for lithium batteries and damage will occur to the battery that is not covered under battery warranty.

Ultimately, using a battery charger with a specific Lithium charge algorithm is the best option for maximum performance and lifespan of any lithium battery.”