Li Ion batteries

[David aka Blue7]

I should perhaps mention that my Banner battery was performing well and I had no issues with it but I recently replaced my wife's golf caddy lead acid battery with a lithium battery and I was astounded at just how much lighter it was so in the true Chapman spirit I decided my next battery would be lithium.  I didn't need to change it just now but I saw a friend's lithium conversion and suddenly experienced a severe bout of upgradeitus and bought the lithium battery and it didn't end there because I continued my infection by purchasing one of Mark's carbon handbrake handles ... and my wife has consulted our Doctor's receptionist (Doctors now seem to be an enigma), and she has booked me in for a consultation with a psychiatrist.  

[Kelv]

Is your JWM still performing ok? I'm thinking of taking the plunge on one of these.

Cheers!

[David aka Blue7]

Kelv, Bizzielizzie13 (#71) has had the JWM longer than I have but in the short time I have had it fitted it seems to turn the engine over quicker than the banner and apart from that it has no issues.  Aesthetically it looks better in the engine bay and is incredibly light.  One aspect I like about it is the digital display on the side of the battery that displays the state of charge, operated by an on/off button alongside the display.  If you have any questions just email Jack Webb, who I found very helpful, 

jackwebbmotorsport@gmail.com

David

[David aka Blue7]

Update on my JWM lithium battery.  I haven't used the 7 for a couple of weeks and when I went to start it yesterday, the battery was flat.  I put it on charge using the charger supplied but the charger light did not illuminate at all.  Connected to my old Banner battery it glowed red and quickly changed to blue.  Regardless, I left it charging my lithium battery during the day but by the end of the day (5 hrs), it was still flat.  I have been in touch with Jack Webb and he has been very helpful and thinks it is a faulty charger and has put a replacement in the post which should arrive on Wednesday so hopefully that will solve the problem.

What concerns me is that the only drain on the battery is the immobiliser and my Banner could cope with that for 4 maybe 5 weeks but the lithium battery only seems to last for a couple of weeks, maybe less but if the charger is faulty maybe it wasn't fully charged at the outset.  Interestingly, Jack tells me that the battery never fully discharges but has a safety cut off limit to prevent it from fully discharging.

I don't have a battery cut off switch fitted and I don't want the hassle of having to disconnect the battery if the car is not being used for just a couple of weeks.  Time will tell and I will see what happens after I receive the new charger and charge the battery again.  However, I have modified my old battery tray to bolt back into position using the new rivnuts that I fitted for the lithium battery tray and my old trusty Banner is now fully charged and ready for action if called upon.

[Roger Ford]

The JWM battery is presumably the 12 AH model. A Banner is (I think) 29 AH. LiIon is great for high output for starting, it's not so great for sustained low loads. Regardless of what Jack might say, AH is AH, and a 12AH battery is going to last less than half as long powering an immobiliser as a 29AH battery. That's why they're generally only recommended if you have a battery master switch.

Unlike a Banner, a good LiIon battery will self-disconnect at a certain voltage so can never run right down and get damaged. A short charge should bring it back over the disconnection voltage and it will be good to go again.

[7 wonders of the world]

I leave mine on a NOCO Genius charger with a timer socket so it gets roughly an hour a day - no problem with immobiliser drain now.

[David aka Blue7]

#80 Roger, you are correct, I have just checked and Lithium battery is 12AH and Banner 30AH so the lithium battery is going to be somewhat inconvenient for me.  An additional problem is that my Halfords jump starter will not function because of the lithium battery UVP (Under Voltage Protection) which shuts the battery down at a specific low voltage so the jump starter thinks the battery is completely flat and will not operate. 

I am expecting the replacement charger tomorrow but I have just taken delivery of a CTEK charger for lithium batteries and reading the instructions it mentions the fact that if charging a lithium battery with UVP it may not charge if it is in Protect mode but there is a "Reset" button on the CTEK that can override the UVP and allow the battery to charge.  In which case I wonder how the basic charger supplied with the battery works, maybe it just charges regardless of UVP?

For peace of mind I think I may revert back to old technology of the lead acid Banner and just have to chalk this down to experience.

David

[BrettJ]

@ Blue7, I have the 12AH battery from Jack and my immobilizer ran the battery down to the point it wouldn't start. I connected my CTEK Litthium XS charger to it and it charged it no problems within a couple of hours, I didn't need to use the reset button.

[David aka Blue7]

Brett, that is the same CTEK charger that I have just bought, after an hour it is now at stage 3 charging with declining current, so at least I know this charger is working ok.  How long had you left your car before the immobiliser ran the battery down?

[Roger Ford]

Yes, the charger supplied by Jack is very basic - probably no more than a simple voltage tranformer - so it won't care whether the battery is switched on or off. It will simply supply a voltage, and then the battery management system in the LiIon battery will detect that and switch the battery back on to start charging. As a smart charger, the CTEK will need to know the state of the battery before attempting to charge it (and will probably be doing reverse polarity detection), hence the need for the reset button saying "turn on the voltage regardless of whether you see any voltage at the other end".

[BrettJ]

@ Blue7, I can start it after a week and a bit, but anything longer it won't. I think it drops +/- 0.1 volt per day.

[Jonathan Kay]

The nominal energy storage capacity (C20):

Banner 53034      30 Ah
Odyssey PC680  16 Ah
JWM PS12          12Ah (36Ah PbEq)
https://jackwebbmotorsport.co.uk/JWM-PS-12-LiFePO4-LIGHTWEIGHT-LITHIUM-BATTERY-p164868003

What does that equivalent in brackets mean?

Thanks

Jonathan

[aerobod - near CYYC]

Hi Jonathan, I think the bracketed number is based on several factors:

1. Usable charge in a lead-acid battery to maintain optimum life is 50% vs 80% in Li-Ion

2. Nominal voltage is 12V vs 13.2V, so Wh capacity for Li-Ion is 10% higher

3. At high discharge rates during starting lead-acid battery capacity drops to about 50% of rated capacity, whereas Li-Ion capacity stays the same.

Basically a Li-Ion battery will look like a lead-acid battery 3x it's capacity during cranking if you do it for long enough to not degrade the batteries future life. In reality for gradual discharge the bracketed amount would look more like a 21Ah battery and the rest is marketing misdirection.

 

[Jonathan Kay]

Thanks

Jonathan

[Roger Ford]

I did a bit of research into that "PbEq" value.

It would appear that under certain, high-drain, conditions lead-acid batteries can only supply about 1/3rd of their rated capacity. Hence Li-Ion suppliers multiply their rating by 3 to give a "lead acid equivalent", or PbEq. That seems spurious for several reasons:

- in a typical low-drain situation such as an immobiliser, it's going to much better than 1/3rd, probably better than 60%
- as Aerobod mentions, Li-Ion won't supply all of their capacity either, though they do a lot better

This slightly ranty article discusses Li-Ion capacity and has some good links.

[Jonathan Kay]

And thanks, Roger.

This thread is fulfiiling its aim in life.

Any more experiences out there, please?

Jonathan

[David aka Blue7]

#85 Many thanks for that explanation Roger 

Do you know why a 'normal' battery charger can't be used to charge a Lithium battery?

David 

[Membership Secretary]

I think that normal battery chargers have stages where they pulse at higher voltages. This is needed to maintain lead acid batteries, but definitely unwanted for Li ion ones.

I bought a halfords intelligent charger, and when I set it to 'Li ion' it skips these stages.

Simon

[David aka Blue7]

To update my situation, I received this advice from Jack Webb:

There is a difference in the capacity of the Banner, but the 12ah is the rating in Lithium Amp Hours - not PbEq Amp Hours as every lead acid battery is measured in. The reason for the difference is down to the usable capacity of the battery itself - a LiFePO4 battery has a far superior usable capacity which is typically around double that of lead acid chemistries. 

Jack also suggested fitting a battery isolator switch along the negative lead which looks like an easier task, for me, and I can fit the switch somewhere inside the car, one of these

https://www.12voltplanet.co.uk/battery-isolator-changeover-switches.html

It would certainly save money in electricity costs because the Lithium battery, if isolated, holds its charge over winter and does not require a trickle charge, which I have noticed with my new lawnmower lithium battery.

At some stage I will determine just how long it takes for the immobiliser to cause the lithium battery to go into LVP mode.

To solve the problem with my Halfords jump start unit not operating because it seels the LVP as a dead battery, I have ordered a NOCO Boost Sport GB20 500A jump starter, which has an override switch that allows it to charge a battery that appears to be dead.

 

 

[Golf Juliet Tango]

Isolating the ground will preserve the battery and I have wired things that way in the past but it isn't a recommended way to kill the engine.

[Bizzielizzie13]

In reply to Blue7's question/s. 

I fitted the Caterham FIA battery cut-off 'kit' as I had heard that the load imposed by the immobiliser would, as with the Banner cause the battery to go flat over time. It was not an easy job, although help with some info (template etc) from JK certainly did help! Had to do some of this upside down under the dash & in the end I had to remove Speedo & Rev Counter to get access & finding the correct wire for the ignition was not straight forward. It was worth it in the end as it now has a 'proper' cut off for Track-Day use & security. Not to mention that thus far at least, I have not had to charge the battery.   

I've have had a few bits from 12v Planet for our camper & found them very good, but you do get everything you need in the Caterham kit, extended cables etc etc & would vote for it as the way to go.

 

[timb2117]

Hi, I have followed this thread keenly, fitted my Lion a short while ago it worked superbly.

After about 2 weeks of no car use it was flat (thank heavens for "in battery" computers that isolate it before it becomes flat dead like a lead acid would've) - I'm guessing the immobiliser.... Nice charge on the NOCO2 and its back to A1.

Sooo - just fitted the FIA switch PURELY to the ground cable from battery (yes I know there are better ways to fit it :) but want utter simplicity for my brain to cope) - which should kill the immobiliser drain.

My Q? is - if I flip the FIA switch to off, and therefore there's no Ground/ circuit could I attach the NOCO 2 and charge it safely without removing the battery cables or do I need to take them both off before charging, like the instructions say.

In anticipation thanks for the know how.  

[David aka Blue7]

#97 I have been charging my Lithium battery while it is still connected via the power socket and no problems.

David

[Jonathan Kay]

"... fitted my Lion a short while ago it worked superbly."

Which model, please?

Thanks

Jonathan

[Jonathan Kay]

"Sooo - just fitted the FIA switch PURELY to the ground cable from battery (yes I know there are better ways to fit it :) but want utter simplicity for my brain to cope) - which should kill the immobiliser drain.

"My Q? is - if I flip the FIA switch to off, and therefore there's no Ground/ circuit could I attach the NOCO 2 and charge it safely without removing the battery cables or do I need to take them both off before charging, like the instructions say."

Is there only the one earth (ground) cable from the battery?

If there is and you've disconnected it with that switch and the conditioning charger is connected directly to the battery then removing any live cables from the battery wouldn't have any further effect.

Jonathan