Lithium Starter Battery

[groeschel Member Find all posts View Profile Close groeschel]

Nope - just used the existing charger. I do, however, use a trickle charger when at home, to "top-up" the battery using 14.7Volts. The car charger doesn't quite get there...(it charges at about 14.1Volts)...

Its a while now since you are using this battery and I am now getting to the point where I might need a new one for the Prado.
Did you find any negatives in the meantime of running it on the normal alternator?
Is the topping up with the trickle charger necessary?
Would be a bit of a hassle on a road trip...

Cheers
Michael

[drivesafe Senior Member Find all posts View Profile Close drivesafe]

Hi groeschel, be VERY careful about using a lithium battery as a cranking battery in a vehicle with low operating voltages, like Toyotas.

While there is a short period of high voltage just after starting your motor, and this will replace the energy used to start the motor and have a lithium battery back in a near fully charged state.

A problem can arise if you use some of the cranking battery’s capacity while the motor is off.

In this situation, if you use some capacity and then start your motor, the high voltage period will not be long enough to fully charge the lithium battery before the operating voltage drops.

Unlike lead acid batteries, which will continue to charge at the lower operating voltage, all be it very slowly, lithium batteries will not charge at the lower voltage.

I suggest you do a lot more research before you take the plunge.

The problem with lithium battery "info" is that there are plenty of experts who know all about lithium battery technology, but these same experts have no idea how vehicle electrics work and this presents a real problem.

If you have a vehicle that runs at 14.0v or higher, you will have no problems but with vehicles operating at the new low voltage levels, there is a potential for real problems, and they could be very expensive ones.

[groeschel Member Find all posts View Profile Close groeschel]

Hi Drivesafe,
thanks for the info.

I understood that the charging voltage of Lithium batteries needs to be higher.
I am using one of this nifty fuses with a diode to increase the charging voltage.
I measured around 14.2 V when the engine is running at the end of a 20 min drive .
I would expect that this after the high voltage peak you mentioned?
From your experience would that be sufficient for a Lithium cranking battery?

Next potential problem I see is that I have a second battery setup with an AGM battery for fridge and accessories. This one is not due for replacement and obviously I would like to replace two batteries
Because of the AGM battery I increased the voltage with the diode some years ago and get very decent usage out of this battery when running the fridge.
I know it is not the best idea to run different batteries (type or capacity) in parallel due to internal resistance and hence different charging speed but it worked so far quite well.

The question is would the Lithium battery as cranking battery change the situation?
Any ideas?

Cheers
Michael

Hi groeschel, be VERY careful about using a lithium battery as a cranking battery in a vehicle with low operating voltages, like Toyotas.

While there is a short period of high voltage just after starting your motor, and this will replace the energy used to start the motor and have a lithium battery back in a near fully charged state.

A problem can arise if you use some of the cranking battery’s capacity while the motor is off.

In this situation, if you use some capacity and then start your motor, the high voltage period will not be long enough to fully charge the lithium battery before the operating voltage drops.

Unlike lead acid batteries, which will continue to charge at the lower operating voltage, all be it very slowly, lithium batteries will not charge at the lower voltage.

I suggest you do a lot more research before you take the plunge.

The problem with lithium battery "info" is that there are plenty of experts who know all about lithium battery technology, but these same experts have no idea how vehicle electrics work and this presents a real problem.

If you have a vehicle that runs at 14.0v or higher, you will have no problems but with vehicles operating at the new low voltage levels, there is a potential for real problems, and they could be very expensive ones.

[drivesafe Senior Member Find all posts View Profile Close drivesafe]

Hi again Michael and thanks to your smart move in fitting the fuse, you will have no problems charging the batteries in parallel.

Where you will have problems is in finding a dual battery isolator that will operate with a lithium battery.

Because of the higher settled voltage of a lithium battery, 13.2v and higher, ( all lead acid batteries have a maximum settled voltage of just 12.7v ), ordinary isolators will actually reaming on until the lithium battery goes flat.

You will probably need an ignition switched type isolator to resolve this problem.

[Tazdevil Moderated member Find all posts View Profile Close Tazdevil]

Hi Guys

I believe you can custom order a Redarc Isolator to your own voltage specs, this might help to solve that issue.

[groeschel Member Find all posts View Profile Close groeschel]

Hhhm, good point.
I have to check but I thought that my isolator is connecting both batteries as soon as the charging voltage gets to something around 12.9V but disconnects as soon as ignition is off ( independently from the voltage)
I did the installation a few years back so I have to check but it definitely required a connection to ignition +

Otherwise, back to the drawing board ;-)

Cheers
Michael

Hi again Michael and thanks to your smart move in fitting the fuse, you will have no problems charging the batteries in parallel.

Where you will have problems is in finding a dual battery isolator that will operate with a lithium battery.

Because of the higher settled voltage of a lithium battery, 13.2v and higher, ( all lead acid batteries have a maximum settled voltage of just 12.7v ), ordinary isolators will actually reaming on until the lithium battery goes flat.

You will probably need an ignition switched type isolator to resolve this problem.

[MNK Junior Member Find all posts View Profile Close MNK]

I personaly would stay away from the idea as they are very unstable and dangerous. be it voltage, heat, charge method. I fly rc helis in spare time and I know the hazards behind them. They do require a different logic when they charge compared to PB lead acid. also a rule of thumb when charging, if you have a cell that is for argument sake 2400mah you would charge it at 2.4a and it would take 1-1.5hrs to fully charge due to the way the logic of the charger charges these cells. I am 100% certain our prado alternators do not have this type of logic and hense why these chargers for these batteries are so expensive (REALLY GOOD ONE)!!! also when charging the batteries they require a cool and non conductive surface. EG concrete, (not hot steel engine bay). Also I would hate to be working in the engine bay and drop a spanner on the + & - terminals as it would create instant explosion and a nice big bang with a huge flame as it puffs up and lets out smoke. Take it Toyota and run if it need to be worked on BAHAHHAH!!!!

[stevensr34 Senior Member Find all posts View Profile Close stevensr34]

I personaly would stay away from the idea as they are very unstable and dangerous.

Sorry, but from what I have read, and I own a LiFePO4 car battery (do you?) - you are "mistaken"

[MNK Junior Member Find all posts View Profile Close MNK]

Sorry, but from what I have read, and I own a LiFePO4 car battery (do you?) - you are "mistaken"

no I don't but its my thoughts so just to add to the ideas of toying around and the dangers I have seen caused by some of these batteries. Here is a question I have; what happens if there is a fault and the battery is the cause would insurance cover it? I wouldnt like to write my kakadu off due to that and not be covered

[groeschel Member Find all posts View Profile Close groeschel]

I dont think that that potential problems are limited to Lithium batteries.
I would say with any high power battery you are running in trouble in case that you create a short with a spanner.
I have seen lead batteries doing very nasty things as well after a short e.g spitting hot acid and melted metal all over the place, causing fire etc

Is there a specific reason why you would see that more problematic with a Lithium battery?

[Bear63 Senior Member Find all posts View Profile Close Bear63]

I think the confusion is coming from using the term "Lithium Battery" , is it a lithium polymer,lithium Ion or a Lithium ion phosphate battery
The ones i think people are using are the latter as they don't have the thermal runaway properties of the former 2
As i have been messing around with all theses batteries for a few years now , still not sure on using one in a modern car
How do they keep the cells balanced? as this is usually required with this type of battery or is it built in

[Bear63 Senior Member Find all posts View Profile Close Bear63]

double post

[MNK Junior Member Find all posts View Profile Close MNK]

I think the confusion is coming from using the term "Lithium Battery" , is it a lithium polymer,lithium Ion or a Lithium ion phosphate battery
The ones i think people are using are the latter as they don't have the thermal runaway properties of the former 2
As i have been messing around with all theses batteries for a few years now , still not sure on using one in a modern car
How do they keep the cells balanced? as this is usually required with this type of battery or is it built in

Sorry, I should have explained myself better too, im talking lithium polymer/LiPo. If you guys are using Lithium as crank batt, which style are they. Ive had a 22.2V 4500mah 50C lipo x2 6 cell (44.4v 12cell) up on me in mid flight with one of my helis due to cables rubbing on carbon fiber. instant fire ball in sky!! very impressive for spectators but not my pocket as $3500 burnt and fell to the ground. :x But as I said just my thoughts on the danger of them and the caution you must take when using and charging them. ALL I CAN SAY IS BE CAREFULL

[Bear63 Senior Member Find all posts View Profile Close Bear63]

I know which lipo's you were talking about MNK,I fly 12s as well

[zzsstt Junior Member Find all posts View Profile Close zzsstt]

I'm also considering using "lithium" batteries. The batteries in question - as shown previously in this thread - are LiFePO4. They are inherently more stable than the LiPO's used in model flight etc. Charging voltage is 3.6V per cell, so 4 cells (nominal 12V) has a charging voltage of 14.4V which is actually below standard lead-acid charging voltage, and is compatible with AGM/GEL voltage.

It is also worth noting that unlike lead-acid batteries, LiFePO4's are not significantly impacted by undercharging (which kills lead-acid batteries very quickly), and combined with their tolerance of higher DOD this means that it is not so important to get to 100% charged. A 60ah LiFePO4 charged to 90% will safely produce far more ah than a 100% charged lead-acid battery of the same nominal capacity. The only real issues are overcharging and overdischarging. An 11V low battery cut-out will protect from overdischarge, the Engel unit that I have is switchable between 10.5V and 11.5V, so the 11.5V setting is fine. Overcharging is a function of increased charging voltage, and a decent charger will cut-off or drop to float without a problem.

Unlike some other forms of lithium batteries, a LiFePO4 battery is very unlikely to become a hazard under all but the most exteme situations, and under those situations lead acid batteries can also explode. A LiFePO4 can be damaged by charge/discharge abuse, but will tend to simply stop working rather than explode.

In my setup I intend to run a Redarc DC-DC charger, and the charge settings for AGM on that controller are perfectly OK for LiFePO4, as confirmed by the battery vendor. The batteries in question are sold specifically as drop-in replacements for automotive batteries, both as starter batteries and deep cycle because unlike lead-acid they are tolerant of high DOD levels AND produce the high currents needed for engine starting.

[I have no association to any battery vendors etc., but I am also looking at LiFePO4's to replace a 400ah 24V solar battery bank, and so am in contact with people using LiFePO4's in off-grid, e-bike and other power storage situations.]