Any good guides to replacing AGM house & starter with LiFeP04?

[Viajero]

Originally Posted by Scalf77

Sure, that would be what it puts out. But, it has to get that power from the 12 DC system. The inverter takes DC battery power and creates AC Power, so 2000 watts / by 12 volts would be 167 amps. Actually a little higher with conversion cost.

-greg

That makes sense. That is some serious amperage and would need some serious cable. Thanks for clarifying.

[Scalf77]

Originally Posted by BCam

Greg is correct but, just to be clear, a 2000 watt converter only puts out 2000 watts and consumes 167+ amps when you're running something that uses that many watts. And most inverters' rating is based on their peak wattage capacity, not their steady state wattage capacity.

Actually 2000 watt inverter is specked to put out a 2000 watt continuous power (if needed) there will generally be couple of different surge power ratings based on time. Example: a 2000 watt Magnum inverter supports 2000 watts continuous, 5 sec surge of 3300 watts, 30 sec surge 3100 watts, 5 min surge 2800 watts, 30 min surge 2200 watts. And while the 167 amps is the easy conversion if you calculate based on low operating voltage that figure can go even higher such as 267 amps.

Originally Posted by Viajero

That makes sense. That is some serious amperage and would need some serious cable. Thanks for clarifying.

And yes a 2000 watt inverter does take some large cables, but the point of the statement is when switching to Lithium you need to make sure your battery bank can support that.

Example: Battleborn 100 Ah 12V LiFePO4 Deep Cycle Battery the built in Battery Management System supports 100 Amps Continuous, 200 Amps Surge for 30 Seconds, ½ Second Surge for Larger Loads. In this case choosing one 100 battery, would mean you would have to be able to derate thew inverter, or provide a circuit breaker to provide protection for the BMS. I only bring this up as many people see the 80% DOD capability and look to go lower than their equivalent AGM bank. Two Battleborn's in parallel would put the continuous rating 200 Amps.

-greg

[moorefc]

Originally Posted by Scalf77

It appears your shore charger is a Tripp-lite RV1512UL inverter/charger which basically only has a Gel & Wet cell setting. This would make this a good choice to be replaced with a unit that supports a lithium and/or programmable charge settings.

-greg

Am I missing something, if you choose Battleborn wouldn't the Tripp-lite work just fine? batleborn batts don't seem to have special needs externally for charging due to their internal BMS...The primary concern with that drop in is the alternator capability, so a DC to DC or Li-BIM would solve that issue?

[Scalf77]

I would disagree that Battleborns don't have specific settings.
From Battleborn
Accepted Voltages:

Charging voltage: 14.2 – 14.6 V
Float voltage: 13.6 V or lower

The BMS does not compensate for wrong voltages settings

It has been a while sense I used a tripp-lite inverter/charger. So off the top of my head I don't remember their exact voltage settings, and their specs don't actually give you voltages. As I said your choices are GEL and WET Cell. So it would be hard to recommend it for Lithium. In general it has very little user control its settings. So yes it is possible that it will work

This is from another thread that I posted in.

So how do you make your standard 3 stage charger work with lithium, a lot depends on your existing charger capabilities. Many chargers actual support a lithium battery or CC/CV charge out of the box, some may just call it a two-stage charge bulk/absorption. The first is relatively easy, we need to set the absorption set point. You need to check the charger, but it will generally give you a voltage that it puts out for different battery types. Even better, is if it allows programming you can put in the recommended voltage from your lithium battery manufacturer. Generally, lithium like somewhere between 14.2 and 14.6. For shore power you need to look at the charge current available, we like to set the maximum charge current at 0.5C or half the Ah capacity. That would be 50 amps for a 100Ah battery. This will also apply to your solar controller, although it may be limited by its output.

For Float we find that a voltage 13.6 and below will not affect the battery. Our goal is to hopefully find a battery type that matches our absorption voltage, and the float voltages we require. Again, some units are fully programmable making this easier.

If your battery has an equalization stage, then you must disable it, if you cannot disable then you must be able to set the voltage to your absorption level.

The next one is absorption time, you thought we already had that done by setting the voltage. Actually, now we need to set how we end absorption. This unfortunately can be done in a multitude of ways and/or combination of events. Typically, the charger determines ending the absorption charge by when the current reaches a certain percentage of the battery capacity. For Lithium that would be around 5% to 10%. Occasionally some chargers will determine done by a timer, in most cases 2 hours would be fine for lithium. Other chargers may use combination of both time and current.

Since lithium doesn’t really like to be charged to 100% SOC a lot could be said for just ending your charge when it reaches the absorption voltage, this usually gets you to about 90% .In any event contact your battery manufacturer, they should be able to give you the best advice for your charger.

Also it would be important to not have temperature compensation enabled if available.

-greg

[moorefc]

Greg
Here is the info on tripp-lite from their techs, and I believe a long time ago this was also on the forum here.
Our inverter chargers use a 3 stage charger. The dip switch for GEL and WET sets the float and absorption voltage as follows.
Absorption/Acceptance
14.4 VDC WET
14.1 VDC GEL
Float
13.5 VDC WET
13.6 VDC GEL


So I believe that is within the Battleborn allowables, making it an option? When I stated special needs, I was referring to profiles of wet and gel batteries, etc....Agree Li chemistry likes partial charge for life cycle and low storage charge....Charge voltage for storage becomes a manual manipulation...Battleborn's warranty, should they exist in 10years, is awesome...Comments?
https://battlebornbatteries.com/char...po4-batteries/

[Scalf77]

Agreed, based on the tripp-lite data I would agree it would be within the battleborn specifications.

-greg