Thread: Lithium, again...

Hi,
Link not working, so not sure of the exact battery you mean.
However, for what it is worth,....
I put a 200AH Fusion battery in my slide on as the 100AH Fullriver AGM was loosing capacity.
Some observations so far.
It is bigger, but lighter. Has some built in smarts such as temperature and current limiting
Will accept 50A till just about on float. (40A recommended)
The fridge cycling on and off barely makes a difference to the voltage graph on the Bluetooth phone app.
Two days camping up the lakes on the June LWE and it charged back to float in about 30 minutes of driving.
Some hassles.
It was advertised as a drop in replacement but that would severely limit its potential.
It does use the dc2dc/MPPT charger (Enerdrive 40Amp) well, both solar and alternator (priority).
I also needed a new 240V charger (50 Amp).
I needed to change/add quite a bit of wiring.
The main feed still comes via the SC 80 Traxide isolator, but it would normally be wired direct to the cranking battery,
The dc2dc will sense the charge and test the cranking battery is being charged before connecting the Lithium.
The charger also has an ignition sensor input so it will connect if that is on.
It was an expensive exercise, but I am confident it will be worth it in the long run.
Cheers

Originally Posted by austastar

Hi,
Link not working, so not sure of the exact battery you mean.
However, for what it is worth,....
I put a 200AH Fusion battery in my slide on as the 100AH Fullriver AGM was loosing capacity.
Some observations so far.
It is bigger, but lighter. Has some built in smarts such as temperature and current limiting
Will accept 50A till just about on float. (40A recommended)
The fridge cycling on and off barely makes a difference to the voltage graph on the Bluetooth phone app.
Two days camping up the lakes on the June LWE and it charged back to float in about 30 minutes of driving.
Some hassles.
It was advertised as a drop in replacement but that would severely limit its potential.
It does use the dc2dc/MPPT charger (Enerdrive 40Amp) well, both solar and alternator (priority).
I also needed a new 240V charger (50 Amp).
I needed to change/add quite a bit of wiring.
The main feed still comes via the SC 80 Traxide isolator, but it would normally be wired direct to the cranking battery,
The dc2dc will sense the charge and test the cranking battery is being charged before connecting the Lithium.
The charger also has an ignition sensor input so it will connect if that is on.
It was an expensive exercise, but I am confident it will be worth it in the long run.
Cheers

Thanks Dave.

Another link for the battery - Search - 12V 100ah Lithium Ion LiFePo4 Deep Cycle Rechargeable Battery

So, is it just a matter of putting the DC-DC between my existing auxiliary in the Defender (which has a Traxide unit between it and the cranker), and the lithium in the camper?

I have been studying this for a while now as I have just fitted a 35AH Lifepo4 to my camper trailer. I am still waiting for the DC DC charger but ran my lights for 3 nights with only a 1hour ac 6amp charge needed to fully recharge .

1 The resting voltage of a lithium is 14.4 volts fully charged and about 13.8 at "float'
if you have a conventional dual battery controller ( which reads the starting battery voltage) I can see the Lithium feeding the Lead Acid until the charges equalize at 12.7or 12.4 or 12 which means lots of capacity loss for the Lithium. As I read it you must isolate the batteries immediately they are not charging with a DC DC charger with ignition cutoff.

2 Also a pure Lithium charger does not have "float" . It immediately turns off once the voltage reaches 14.4 or thereabouts, Thus the red and green lights on the 240 volt chargers. I wonder if my NOCO ( lead AGM Lithium) charger for the wife's Lithium Golf battery failed because of this.

3 AFAIK none of the DC DC chargers readily available have the "turn off" feature. I have a Turnigy 10 amp or 80 watt dc dc charger on order from Hobby King , which I will power through a relay activated for accessory off or on, from my rear cigarette plug as it is easier than powering it from IGN. The Turnigy is only say 8 amps at 4xLifepo4 but this is within the envelope for the battery. It also has a timer turn off period mainly for lion . I do not know the "cut in" voltage but I have never seen my wife's battery cut in as Lithiums retain their voltage very well. I measured hers at 13.88? after 1 week off charge.

4 I am going to isolate the trailer power while charging the camper battery by switching off the trailer plug power wire as it will be in the circuit for the lights.

My requirements are pretty specific as I did not have a battery in my camper and relied on the car connection via an extension cord from the trailer plug. I plan to fit a small water pump as well and if the LIfepo4 is anywhere near 35AH, I should have no trouble running for several days.

Regards Philip A

I’m a little daunted on battery selection, there is a big range in pricing.

I am certain a DC-DC is required

Originally Posted by Ranga

Thanks Dave.

Another link for the battery - Search - 12V 100ah Lithium Ion LiFePo4 Deep Cycle Rechargeable Battery

So, is it just a matter of putting the DC-DC between my existing auxiliary in the Defender (which has a Traxide unit between it and the cranker), and the lithium in the camper?

Hi,
That is what I did. (But from the back of the Traxide)
I also ran a trigger from ignition to the appropriate pin on the dc2dc charger while I was mucking about with wiring.
Cheers

Drivesafe has posted that a DC-DC is essential to properly charge a lithium battery, because they require a higher charging rate, but no doubt he can explain that better than me.

Hi Mick and I have been following this thread, but because I sell another brand of Lithium batteries, I did not want to run down some other brand.


While it is always a case of “Buyer Beware” but this is not how it should be on AULRO.


Some time back I did some research on these cheap Lithium batteries and I was not all that impressed.


They are made using a lower standard lithium cell but will most likely work just fine for the basic camping needs, like running a fridge and some lights and powering a “SMALL” inverter.


It’s the use of inverters that could pose a problem with these batteries, primarily because of the low rated BMS they come with.


The margin of error is pathetic and if you ran anything bigger than a 1000w inverter, you will most likely damage the BMS and if it is damaged in this type of operation, no warranty.


Their maximum operating current is 80 amp but just 25% more and you have reached their peak. Not much margin of error there.


Now to charges. Any type of charger, be it a 240VAC charger or a DC/DC charger, as long as the charger is specifically designed to charge lithium batteries, they should be fine.


A word of caution, lithium batteries are very hard on most types of chargers.


Philip is correct in that a lithium charge cycle should fully charge a battery and then “turn off “


But you can use a setup that charges at say 14.4v in BULK and ABSORPTION, and then drops to to 13.6v in float. This is because there will most likely be no current draw at 13.6v.


One more curious thing about those batteries. They have a MINIMUM charge current requirement of 10 amp. That is a rather strange requirement!

Thanks everyone.

Tim,
Do you have a wiring guide that suits my needs - currently a cranker and an AGM deep cycle separated by an SC80, with the need to replace the AGM deep cycle in the camper - that works when replacing the camper AGM with lithium?