Battle Born LiFePO4 batteries

[uncle_bob]

Originally Posted by uncle_bob

Hi

I understand the whole "inside / outside" tradeoff thing. For some inside makes more sense than outside. A lot depends on your trailer floor plan and what you have squeezed into where. For others outside may make more sense. Outside also gets you into the whole "keep the shunt dry" nonsense. No one size fits all answer.

Has anybody who went the "outside" ( put them in the battery box) approach had trouble fitting two batteries in the standard AS enclosure? From the specs, they *are* just a bit bigger than a standard group 27. There's also the battery lug difference ....

=====

On the diode thing: With a dead TT system (at < 10V) and the TV alternator at 14.5V, you very much *do* need a heatsink. Something with a thermal resistance below 10C/W is a likely requirement.

Bob

Hi

Well, now I can answer my own question

Just to keep things tidy - the answer is that the Battle Born's fit just fine in the battery box on my trailer. That makes it a *very* easy to double your usable amp hours. Of course I went a bit further ... details scattered in a number of threads.

Bob

[Gsmblue]

Just a quick note: the new pd4655 lithium converter is holding a steady 14.53v and the SOC is steady at 100%. It would appear with the older version of the pd4655 as it dropped to float the batteries would indeed “leak”.

If anything changes I will update..

[TheGreatleys]

Originally Posted by Gsmblue

Finally installed the PD4655 Lithium charger and a battery disconnect on the negative side of the battery before the shunt (Victron 702 battery monitor). Now my batteries show the SOC being at 100%.

When the Airstream is parked at home in the garage/living room I can disconnect the batteries and not subject the battle or s to excessive cycles!

The new disconnect is in the bottom left of the pic, accessed from the storage hatch.

You might consider moving your hot lead to the other battery to even out the wire distances across the battery bank. In the current configuration, one battery is closer to the loads than the other, so it will wear unevenly over time.

[uncle_bob]

Originally Posted by Gsmblue

Just a quick note: the new pd4655 lithium converter is holding a steady 14.53v and the SOC is steady at 100%. It would appear with the older version of the pd4655 as it dropped to float the batteries would indeed “leak”.

If anything changes I will update..

Hi

The gotcha with running at 14.6V all the time is wearing things out from always having them on "supercharge" mode. When a charger drops back to 13.5 (or so) volts, the BMV will see a bit of current going out of the battery. This is just physics in action and it does not indicate a fault. It's not enough amp hours to really impact the life at all. If the charger drops to 13.2V, then quite a bit of charge will dump from the Battle Born's, that's a bit more of an issue.

Bob

[Gsmblue]

Originally Posted by TheGreatleys

You might consider moving your hot lead to the other battery to even out the wire distances across the battery bank. In the current configuration, one battery is closer to the loads than the other, so it will wear unevenly over time.

Yep! The cable was supposed to be over there... somehow I missed it! Next time I pull the couch apart I will move it!

[mythbuster88]

Originally Posted by Gsmblue

Finally installed the PD4655 Lithium charger and a battery disconnect on the negative side of the battery before the shunt (Victron 702 battery monitor). Now my batteries show the SOC being at 100%.

When the Airstream is parked at home in the garage/living room I can disconnect the batteries and not subject the battle or s to excessive cycles!

The new disconnect is in the bottom left of the pic, accessed from the storage hatch.

What is the battery strap connected to?

[mythbuster88]

Originally Posted by Gsmblue

Just a quick note: the new pd4655 lithium converter is holding a steady 14.53v and the SOC is steady at 100%. It would appear with the older version of the pd4655 as it dropped to float the batteries would indeed “leak”.

If anything changes I will update..

I get the same performance with my charger which seems to be an acceptable voltage.

From BB:

"Among charging algorithms for lead acid batteries, there is a wide variation for these values. The bulk and absorption voltages typically vary between 14.0 and 14.8 V and the float can vary between 13.2 and 13.8 V. The 12V Battle Born batteries sit comfortably right in the middle of these ranges. We recommend a bulk and absorption voltage of 14.4V. A float is unnecessary, since Li-ion batteries do not leak charge, but a floating voltage under 13.6V is fine."

[Troutboy]

Originally Posted by mythbuster88

What is the battery strap connected to?

Usually a cleat such as the one below:

https://www.amazon.com/Amarine-made-...GTL&ref=plSrch

[Gsmblue]

Originally Posted by Troutboy

Usually a cleat such as the one below:

https://www.amazon.com/Amarine-made-...GTL&ref=plSrch

In between the batteries there is one cleat as per that link, then the outsides are held in by angle iron and the strap goes around that.

Not budged at all since I put them in a year ago.

[Gsmblue]

Originally Posted by mythbuster88

I get the same performance with my charger which seems to be an acceptable voltage.

From BB:

"Among charging algorithms for lead acid batteries, there is a wide variation for these values. The bulk and absorption voltages typically vary between 14.0 and 14.8 V and the float can vary between 13.2 and 13.8 V. The 12V Battle Born batteries sit comfortably right in the middle of these ranges. We recommend a bulk and absorption voltage of 14.4V. A float is unnecessary, since Li-ion batteries do not leak charge, but a floating voltage under 13.6V is fine."

The problem I had was over time the batteries were slowly discharging and never fully recharging. At one point they would only change to 60% SOC according to my VM702. Even when I put the charger in boost mode.

Now they are sat at 100% SOC and I have a -ve disconnect so I can truly isolate the batteries if I want too.

[uncle_bob]

Originally Posted by Gsmblue

The problem I had was over time the batteries were slowly discharging and never fully recharging. At one point they would only change to 60% SOC according to my VM702. Even when I put the charger in boost mode.

Now they are sat at 100% SOC and I have a -ve disconnect so I can truly isolate the batteries if I want too.

Hi

If indeed you have a charger that goes down to 13.1 or 13.2V and sits there, your lithium's will get down to 60 or 70% charge. Since this is a "float" voltage on most chargers, the charger *should* go back into charge mode once they get to the 60% level. At that point they would ramp back up to 100%. If your charger does *not* come out of the 13.2V mode ... it's either broke or ...errr ... broke.

To me, the impact of running the batteries down by 30 or 40% on a regular basis seems like needless wear and tear. You can run things to "idle" at 13.5 or 13.6 (instead of 13.2 or 13.1). That keeps things within a percent or two of full charge. When the charger goes into "once a week" mode and boosts to 14.4V ( to equalize the cells) the amount of charging is pretty modest.

Bob

[SilverHouseDreams]

Originally Posted by Gsmblue

The problem I had was over time the batteries were slowly discharging and never fully recharging. At one point they would only change to 60% SOC according to my VM702. Even when I put the charger in boost mode.

Now they are sat at 100% SOC and I have a -ve disconnect so I can truly isolate the batteries if I want too.

This "plug and play" nature of these is what lead to this thread being created: http://www.airforums.com/forums/f449...rn-173827.html

Further, you will see that depending your TV your BattleBorn will also _discharge_ into your TV while towing or when parked with the 7-pin connected. YMMV, but that thread also discusses that subject and options to address it.

[uncle_bob]

Hi

Indeed, the whole "use it with anything" side of the internal BMS designs ( of which Battle Born is one) makes figuring out what is what a bit more difficult. The first line of "yack" from all the manufacturers is "it works with anything". Digging in past that is not as easy as it might be. To some extent, it only makes sense once you have a battery bank and fully programable charging gear.

Bob

[mythbuster88]

Originally Posted by Gsmblue

The problem I had was over time the batteries were slowly discharging and never fully recharging. At one point they would only change to 60% SOC according to my VM702. Even when I put the charger in boost mode.

Now they are sat at 100% SOC and I have a -ve disconnect so I can truly isolate the batteries if I want too.

Over how much time?
I don't understand how you can only get to 60% SOC?

When we turn on the two PD9160AL, two in parallel to charge two 100Ah BattleBorns in parallel, they kick ass at 110 Amps total until around ~96% SOC then they back off and sit at ~14.5 Volts until 100%SOC putting out ~.5A forever.

[Troutboy]

Why two myth? Those holes look straight, and aligned, well done! How did you do that so well? I would have destroyed that for sure

[mythbuster88]

Originally Posted by Troutboy

Why two myth? Those holes look straight, and aligned, well done! How did you do that so well? I would have destroyed that for sure

Thanks. I took the panel off and just measured and marked where I wanted the holes and used an automatic center punch at each mark. Then drilled holes by hand.

BB recommends a 60A charger for one battery. I have two batteries so I got two chargers. Progressive Dynamics fine print says the chargers can be in parallel.

The idea is when I do have to charge the batteries with a generator I want to get it done as fast as possible.

This entire project is geared for camping when its cold and we have to run that forced air heater. With the stock setup we were only good for one night and then the batteries were shot. Once that happened the batteries could never recover and we had to use the generator constantly to protect the batteries. I figure we can go for three nights now watching movies, lots of lights, heater, cold beer, music. You know, camping!

[uncle_bob]

Hi

In a previous post BB mentioned that they test their batteries at two charge / discharge rates. One is at 100A and the other is at 20A. Both numbers are for a single battery. They get a bit longer life at the lower rate..... hmmm .... two batteries -> 200A at 14.4V is 2.9 KW from the generator ... yikes !!!

Indeed the lack of a "taper phase" where you charge forever and ever to get the last 20% into the battery is significant when charging lithiums from a generator.

Bob

[HUSK N TUSK]

I like that all the holes are lined up with each other and meticulously laid out.

But...why are they not centered at all on the door? They are cocked way right. Caught my eye immediately.

I thought perhaps Airstream had done it initially until I opened the thread.

Was there a reason for the offset of the holes? Some obstacle in the way or for better cooling?

[uncle_bob]

Hi

If you really want to go nuts with cooling .....

The basic idea is "don't mix hot and cold air". In an enclosed space (even with vent holes) the air just spins around. Hot air comes out the back of the converters and routes back into the fans on the front. Baffles are the basic answer. Suck the cold air in through the holes, blow it out the back and out somewhere else.

Yes, that can be a bit of work. In some cases you just happen to luck out and can mount things so it works that way using obstacles that are already present.

Since all the air is in the RV already, the whole "don't mix" thing *is* relative. The better you can isolate the two, the more effective the cooling will be.

If you are running 100A at 14.4V and the converters are ~90% efficient at that point you are putting around 144W out as heat. That's enough to get a small space fairly warm .... A quick check is to put your hand on the case of the converter after it has been on for a while. If it feels hot ( = can't touch it for a 10 count), that's a good reason to improve things.

Bob

[Gsmblue]

Originally Posted by mythbuster88

Over how much time?
I don't understand how you can only get to 60% SOC

I don’t understand either, but that is what happened. Now I have the new charger in place everything is working well.