Conversion to LiFePO4 Batteries - Main Battery Charging Problem?

[blpostma]

Originally Posted by 153stars

Also the issue is the life batteries can draw more amps than your alternator can to deliver for it heat or heat wise continuously. A 200ah Life batt might accept 1C charge Depending on BMS profile . So it could pull 200A from the alternator on its own.

Yes, I am aware of this. I did not mention in my original post that I was planning to install a 40 Amp Renogy DC to DC converter to charge my new house batteries from the 230-amp alternator. I haven't yet decided if it's worth the hassle since I have 300 watts of solar, I rarely dry camp, and I only travel in the American Southwest, where it's usually sunny. I guess I had better decide before the Amazon return window closes.

[blpostma]

Originally Posted by blpostma

Thanks, I think you are correct. Thinking it through, we never have the RV on shore power more than 4 weeks at a time and that's when parked at home. If we are concerned with the chassis battery discharging, we can hook a float charger up to it, just as we do with a car we have in the garage which is rarely driven. We have never stayed at a campground for more than a week. The only time we ran down the chassis battery is when we left the headlights on. I'll disable the interconnect switch. From what I can see on the BCC block diagram, we will still be able to parallel the batteries for an emergency start with the auxiliary start switch on the dash. We also have a towed car that we can use for an emergency jump. So, no need to take a chance on boiling the chassis battery.

After looking at the BCC wiring diagram again, I was wrong. The emergency start button uses the same interconnect solenoid. If we ever need to do that (once in 10 years so far), I can just plug the F22 fuse back in, or just jump the battery from our toad.

[153stars]

You "thinking" you should be able to disable BIRD part and keep emergency start/boost switch. Sounds like your already convinced to keep BBC also good in case you need to combine due to failed alternator and run on the genny/house batts.
I watched vid on Bluesea made because of people being worried/questions of huge surge combing two large groups of LA batteries. One set high and one set low there was brief surge but nothing crazy ,then they just started pulling a good charge. These were LA to LA. but the idea is that LA set is not going to draw too heavily because of resting voltage of the higher set of batts.
I was on an internet deep dive about MTL-ACR and I can't locate the vid right now ,they have a lot of them.

[BigEvi]

Originally Posted by blpostma

...or just jump the battery from our toad.

you could jump the chassis batt from the house Batt while it's being charged by shore or gen.

[vsheetz]

Originally Posted by twinboat

A diversion charger like the Amp L Start will overcharge the chassis battery.

A second 10 amp battery to battery charger will be able to be adjusted to lead acid float voltages.

The AmpLStart should not overcharge the chassis battery. It adjusts charging current based on chassis battery SoC. It also limits charging voltage to 13.8v.

There is also now available a capability to disable it when using with a DC2DC charger.

...From LSL website...

"HOW IT WORKS -*Connected between your house and engine starting batteries,*AMP-L-START*"steals" some of the charging current from your house battery charger (or solar panels) to also keep your engine starting batteries charged. Whenever no house battery charging source is present, it automatically shuts down, thereby preventing any reverse current flow back into the house batteries.

The*charging current is continuously adjusted to whatever amount is necessary to recharge and maintain your starting batteries - It can vary from 0 to 15 amps, depending on the battery's state of charge.*AMP-L-START*works with single- and dual- starting battery systems, and is compatible with all battery types - Gell-Cell, AGM, "Maintenance-Free" and conventional flooded-cell. It is also compabible with LiFePO4 "lithium" house batteries (Battle Born and similar).

The current revision includes*user-selectable "HIGH TEMPERATURE" and "LITHIUM" modes that modify the turn-on and turn-off voltages, for computability with LiFePO4 Lithium house batteries and temperature-compensated house battery chargers. Either of these modes can be enabled by installing a jumper (included) across two pins on the back of the unit.

The "HIGH TEMPERATURE" mode changes the turn-on and turn-off voltages to 12.7 and 12.5 volts, respectively.

The "LITHIUM" mode changes the turn-on and turn-off voltages to 13.45 and 13.35 volts, respectively.

Removing the jumper instantly restores the "NORMAL"* 13.2/12.8 volt turn-on/turn-off settings.

A*built-in beeper sounds an audible*Low Starting Battery Alarm*if your starting battery voltage drops below approx. 11.9 volts. This feature helps protect your starting batteries, by warning you of a charging problem before the batteries become discharged to the point of permanent damage.

An*Overvoltage Protection*feature* automatically limits the maximum starting battery voltage to 13.8 volts, regardless of the house battery voltage. This allows conventional lead-acid starting batteries to be safely used in conjunction with LiFePO4 house battery chargers that may produce a much higher voltage."

[blpostma]

Originally Posted by 153stars

You "thinking" you should be able to disable BIRD part and keep emergency start/boost switch. Sounds like your already convinced to keep BBC also good in case you need to combine due to failed alternator and run on the genny/house batts.
I watched vid on Bluesea made because of people being worried/questions of huge surge combing two large groups of LA batteries. One set high and one set low there was brief surge but nothing crazy ,then they just started pulling a good charge. These were LA to LA. but the idea is that LA set is not going to draw too heavily because of resting voltage of the higher set of batts.
I was on an internet deep dive about MTL-ACR and I can't locate the vid right now ,they have a lot of them.

This is my first time posting on IRV2, and I'm having difficulty interpreting your post.

What is BIRD?

MTL-ACR?

I found the Buesea website, but it sells a huge variety of equipment. What device are you referring to?
Also, just to note, the BCC cannot be removed - it contains about 30 fuses, circuit breakers, solenoids and relays for everything from the horn to the steps. It's a monster.

[blpostma]

Thanks for pointing me to the AmpLStart. I don't think I will need it (my RV rarely sits for more than a few weeks), but it looks like it will do the job at a reasonable price.

[twinboat]

Originally Posted by vsheetz

The AmpLStart should not overcharge the chassis battery. It adjusts charging current based on chassis battery SoC. It also limits charging voltage to 13.8v.

There is also now available a capability to disable it when using with a DC2DC charger.

...From LSL website...

"HOW IT WORKS -*Connected between your house and engine starting batteries,*AMP-L-START*"steals" some of the charging current from your house battery charger (or solar panels) to also keep your engine starting batteries charged. Whenever no house battery charging source is present, it automatically shuts down, thereby preventing any reverse current flow back into the house batteries.

The*charging current is continuously adjusted to whatever amount is necessary to recharge and maintain your starting batteries - It can vary from 0 to 15 amps, depending on the battery's state of charge.*AMP-L-START*works with single- and dual- starting battery systems, and is compatible with all battery types - Gell-Cell, AGM, "Maintenance-Free" and conventional flooded-cell. It is also compabible with LiFePO4 "lithium" house batteries (Battle Born and similar).

The current revision includes*user-selectable "HIGH TEMPERATURE" and "LITHIUM" modes that modify the turn-on and turn-off voltages, for computability with LiFePO4 Lithium house batteries and temperature-compensated house battery chargers. Either of these modes can be enabled by installing a jumper (included) across two pins on the back of the unit.

The "HIGH TEMPERATURE" mode changes the turn-on and turn-off voltages to 12.7 and 12.5 volts, respectively.

The "LITHIUM" mode changes the turn-on and turn-off voltages to 13.45 and 13.35 volts, respectively.

Removing the jumper instantly restores the "NORMAL"* 13.2/12.8 volt turn-on/turn-off settings.

A*built-in beeper sounds an audible*Low Starting Battery Alarm*if your starting battery voltage drops below approx. 11.9 volts. This feature helps protect your starting batteries, by warning you of a charging problem before the batteries become discharged to the point of permanent damage.

An*Overvoltage Protection*feature* automatically limits the maximum starting battery voltage to 13.8 volts, regardless of the house battery voltage. This allows conventional lead-acid starting batteries to be safely used in conjunction with LiFePO4 house battery chargers that may produce a much higher voltage."

That's for the update. So the buyer needs to look for the updated H5 Amp L Start , not old stock.

[153stars]

BIRD...... Bi‐directional Isolator Relay the solenoid might be called Big boy solenoid but it's brain control is the bird delay board/ module . Early ones large black plastic relay , later on green circuit board.
Bluesea ML-ACR magnetic latching automatic charge relay. Stand alone smart charge relay with very low power draw. In my case replaced diode isolator, jump start solenoid and gave me bi- directional charging. and manual and by the switch combine or manual lockout or by the switch combining.
I actually messed up the acronym BCC thought you wanted to remove the large isolator relay.
I was suggesting its possible to disable the auto combine/smart function and still have use of jumpstart switch at dash.

Originally Posted by blpostma

This is my first time posting on IRV2, and I'm having difficulty interpreting your post.

What is BIRD?

MTL-ACR?

I found the Buesea website, but it sells a huge variety of equipment. What device are you referring to?
Also, just to note, the BCC cannot be removed - it contains about 30 fuses, circuit breakers, solenoids and relays for everything from the horn to the steps. It's a monster.