Thread: Lithium Start Battery

Hi Dave, correct me here if I have this wrong, but from memory ( and my memory is not that good ) you have a DC/DC charger charging your Lithium batteries in the tray.

If this is correct, then the DC/DC device MUST BE ignition switched, not voltage level switched.

Other than that, all should be fine.

Originally Posted by Witchdoctor

I hope there are some smart members that can set me right.

Can i swap out my lead acid start battery for an equivalent voltage, CCA & charge rate Lithium?
Looking to save some weight in my little truck.

Cheers
Dave

Be interested in your selection

drivesafe,

I do have a DC2DC charger to charge my AGM duel battery.
As the DC2Dc charger can also charge Lithium I'm looking to start replacing all my batteries to Lithium starting with the start battery then the duel.
Im hoping the Lithium starter can be a direct drop in replacement for the lead acid starter without any issues.

Since posting i have found a company that can supply me a Lithium starter that they say is a drop in no issues.
Battery weighs 3.4Kg & about half the size of the lead acid starter.
I have also sourced a Lithium duel that is 120Ah with the same footprint as a 120Ah Fullriver, it weighs 10Kg.

Cheers
Dave

Hi Dave, you will still need to have the DC/DC device Ignition switched.


The reason is that a lithium battery has a settled voltage of 13+ volts and it will maintain that voltage over most of it’s discharge cycle.


It will only begin to drop in voltage as the battery nears 20% SoC.


Because the automatic cut-out ( turn off ) voltage level of most DC/DC devices is 12.7v, the settled voltage level of a lithium is too high and if the DC/DC is set to voltage monitoring instead of Ignition, the DC/DC will remain on, flattening your cranking battery.

Again, other than that, it should still be a straight changeover for the cranking battery.

Thanks safedrive,

Im yet to run the ignition switch wire on the DC2DC charger but it has now gone to top of the list.
You have made me feel loads better about stepping up to Lithium batteries.

Cheers
Dave

So does that mean if you don't have a DC-DC then a lithium starting battery should just drop straight in?
If it's half the size that should save a fair bit of space.
Are there any venting or cooling issues with using lithium?
Can I also ask about the price comparison?

DiscoMick,

Your on track.
The only issue is the cost. The Lithium starter I'm looking at is around $650.
The pick up is all around the weight, it weighs 3.4Kg compared to 27Kg's for my current starter.
Then I'm running a 33Kg AGM duel, by changing this to Lithium that weighs 10.2Kg's.

There are other +'s when converting to Lithium but the cost is by far the biggest negative to get past.

Cheers
Dave

HI Dave, do you have specs for the lithium batteries you are considering buying?


The reason I ask is that there is a lot of misinformation about what size lithium battery can replace what size lead acid battery.


For instance, a considerably smaller lithium battery can be used as a starting battery, because you only require a large current supply for a very short time, and this is something the correct type of lithium battery is ideal for.


Whereas, if you need a 120Ah lead acid battery to meet your camping needs, you need the exact same size lithium battery, to be able to meet the same needs.


There is a lot B/S being used to market lithium batteries, particularly when relating to the size replacement required.


A 100Ah AGM battery will give you roughly 80Ah of usable capacity, and a 100Ah lithium battery will also give you no more than 80Ah of usable battery capacity.