Why not change the second battery to Lithium?

[Kruegerruda]

Is it not possible to replace the second battery with a lithium battery and use it as a supply battery? The second battery is charged via the alternator and disconnected from the starter battery by the Smartpas. Or am I seeing this wrong?

 

[anand]

Lithium batteries utilize a different charging profile than the EFB batteries (both starting and second).

If you replaced the SmartPass with a DC-DC charge controller, with lithium specific output voltages, then you could absolutely use lithium for the second battery; this is my plan.

 

[nuclearmonkey]

My understanding is that a potential downside is during heavy load where two same type batteries can be linked together, the lithium can not. Example would be winching.

 

[anand]

My understanding is that a potential downside is during heavy load where two same type batteries can be linked together, the lithium can not. Example would be winching.

This would be accurate for some battery isolators, however, that is not exactly how the SmartPass120 operates.

The SmartPass120 sends power from the aux battery to the starting battery in one of two instances:

1. The aux battery can send a low amperage charging "pulse" to attempt to continuously recharge/top off the starting battery, from previous threads I think I remember the charge rate to be ~5A
2. If the starting battery voltage reaches 9.5 volts, it will connect both batteries for a period of 10 seconds. This is specifically intended to sense a dead main battery that is attempting to start the vehicle, and the 10 seconds is with the theory that will be long enough for the engine to start and the alternator to start supplying power.

Some other isolators will simply direct connect the batteries when the voltage on either side is high enough (for instance, the Blue Sea ML-ACR). The ML-ACR also has a switch to force the connection (or disconnection), and thus you could force connect both if you were doing a very extended winching operation; but in almost all cases, the battery drain from the periodic nature of winch pulling/reseting is kept up with by the alternator output.

 

[nuclearmonkey]

Appreciate the reply. I wasn’t referring to the smartpass per se… It’s been about 8 months since I spoke to them, but I had a call to Lifeline about replacing my house battery in my defender with a lithium. They advised against for any of the times the batteries could possibly be joined due to chemistry and voltage differences. The lithium IIRC, couldn’t handle the sudden high amperage draw (say winching). I believe they also advised against using it to jump the starter for similar reasons. The battery would shut itself off as it sensed the massive current draw - before the starter battery would have enough time to jump. I believe this is why a lot of the Aussie trucks are running dual agm’s with a lithium as well.

If kept effectively separated… then obviously totally different conversation

 

[Xrford]

I see Dakota Lithium has a line of LifePo4 lithium batteries called DL+ that are a hybrid of starter and deep cycle.

AN ULTRALIGHT ALL-PURPOSE BATTERY FOR BOTH STARTING ENGINES & DEEP CYCLE APPLICATIONS

Supposedly it is a drop in replacement for most automotive starter batteries. I am wondering if it could be an option for replacing the auxiliary battery on the Grenadier when connected with both the cteck 120s and 250se?

Here is a link

It says for the 135ah version

MAX CHARGE / ALTERNATOR SIZE
Peak charge acceptance 165A max for one minute, 200A max BMS cutoff. Drop in replacement for lead acid and AGM starter batteries for vehicles. Limited to a max alternator size of 150 amps or less per battery (link multiple batteries in parallel for alternators >150 Amps).

Wondering what the Grenadier alternator output is?

Any thoughts on its suitability for an auxiliary battery replacement.

 

[anand]

Wondering what the Grenadier alternator output is?

Any thoughts on its suitability for an auxiliary battery replacement.

Alternator output is >200A from what I recall; not to mention that it will never charge a LiFePO4 to anywhere near full capacity (since the charge profile is totally different).

Yes it "could" drop in, but it isn't ideal as a drop in replacement in modern vehicles.

As an aux battery, it could be great (with an appropriate DC-DC charge controller), this is actually the battery I have ordered to use as my aux battery (being charged with a Victron Orion XS from the main battery/alternator).

 

[Xrford]

@anand The DL+ as an auxiliary battery replacement, the smart pass 120 combined with D250SE would limit the charging amps to 140A so the DL+ would not see the max 200A of the alternator anyways. As per the not being able to fully charge the lithium battery, the D250SE has a lithium charging profile, so it should be able to top up the charge to the max. This would then allow it to function as a backup to the starter battery if the starter battery is down on charge using 120s features as per the factory setup. Using the victron Orion xs would you not lose this feature?

 

[anand]

@anand The DL+ as an auxiliary battery replacement, the smart pass 120 combined with D250SE would limit the charging amps to 140A so the DL+ would not see the max 200A of the alternator anyways. As per the not being able to fully charge the lithium battery, the D250SE has a lithium charging profile, so it should be able to top up the charge to the max. This would then allow it to function as a backup to the starter battery if the starter battery is down on charge using 120s features as per the factory setup. Using the victron Orion xs would you not lose this feature?

I don't believe the SmartPass 120s alters voltage or amperage (only limiting the amperage), thus from alternator charge the aux LiFePO4 would never get the optimum charge profile.

The D250SE solar controller could put out a generic LiFePO4 charge profile (I don't believe you can modify them on that unit), which is probably good enough for most batteries. In this configuration you would be relying on the solar controller to handle the last 10-15% SoC for the LiFePO4 that the alternator couldn't do.

In this case, you're correct, the SmartPass 120 would still trickle charge the starting battery. But that feature is effectively useless if you wire all your aux loads to the aux battery.

Thus in my set up I don't have a reason to trickle charge the primary battery as nothing runs off of it when the vehicle is off, and if for some reason it is flat, I carry a small lithium jump pack

 

[Xrford]

The D250SE solar controller could put out a generic LiFePO4 charge profile (I don't believe you can modify them on that unit), which is probably good enough for most batteries. In this configuration you would be relying on the solar controller to handle the last 10-15% SoC for the LiFePO4 that the alternator couldn't do.

The D250SE is not just a solar controller it is a DC to DC Charger as well, delivering up to 20A of charge. It would be able to charge a lithium battery to full state of charge off of the alternator when the engine is on and can also charge the auxiliary battery off of the solar input when vehicle engine is off. In addition once the auxiliary battery is fully charged it can trickle charge the starter battery from the solar input as well.

This setup does not preclude you from connecting all your consumers off of the auxiliary battery, but also retains the OEM wiring configuration and these key functions that smart pass 120s provides:

• Start assistance ( since the Dakota lithium DL+ Battery can deliver 1000CCA this would also work)
  SMARTPASS 120S automatically connects the service battery to the starter battery for 10 sec to assist, if the starter battery on its own is unable to start the engine. After the start assistance func- tion has been activated, SMARTPASS 120S will display a fault indication until starting has been achieved without using the start assistance function.
• Starter battery trickle charging (Since the simple act of opening the doors seems to deplete the starter battery this feature is most likely going to come in handy in a multi day camping scenario)
  The service battery trickle charges the starter battery without assistance from the solar panel or alternator to compensate for the self-discharge of the starter battery. The service battery charges in 3-second pulses when its voltage is higher that of the starter battery and the voltage of the starter battery is low.

I really see no downside, just upside from this setup.

 

[NQ94]

For Australia, people may have to look up the new regulations, December 23, in regard to fitting lithium batteries, solar, fusing and venting particularly if the vehicle is going to be used as sleeping quarters. Most of the new rules apply to caravans and motorhomes but it is worth a look so not to void insurance.

 

[trobex]

In all of my experiences, lithium batteries have let me down. Many of my greviances with both boat and car has been the result of lithium. I've been stranded by lithium several times!!!

 

[trobex]

For Australia, people may have to look up the new regulations, December 23, in regard to fitting lithium batteries, solar, fusing and venting particularly if the vehicle is going to be used as sleeping quarters. Most of the new rules apply to caravans and motorhomes but it is worth a look so not to void insurance.

Simply not worth the increased risk of fire. I won't put my family in jeopardy. Sure, they are good in phones and watches...

 

[Xrford]

Simply not worth the increased risk of fire. I won't put my family in jeopardy. Sure, they are good in phones and watches...

Lithium LifePo4 batteries that we are talking about here, are a lot less volatile and will not catch fire, not to be confused with lithium ion that are prevelent in EVs,laptops,phones and can catch fire See Here

 

[NQ94]

Lithium LifePo4 batteries that we are talking about here, are a lot less volatile and will not catch fire, not to be confused with lithium ion that are prevelent in EVs,laptops,phones and can catch fire See Here

New Australian minimum standard regulations are for all lithium and solar installs in RVs and campers, including LIFePO4. A lot of the new standard refers to the prevention of gasses entering habitation/sleeping spaces in the event of a battery fault.

 

[trobex]

New Australian minimum standard regulations are for all lithium and solar installs in RVs and campers, including LIFePO4. A lot of the new standard refers to the prevention of gasses entering habitation/sleeping spaces in the event of a battery fault.

This is correct. This will apply to cabin spaces of any registered vehicle or other plant or machinery in which workers may be required to operate from - I already have to include these in Work Risk Assessments and have been since early last year. My insurer has put a notice out already regarding such for Boats, Vans, Vehicles/Plant/Machinery with Cabin spaces etc. Remember, adding such batteries to any plant, machinery, equipment or vehicle also requires you to notify you insurer of the change.