Battle Born LiFePO4 batteries

[waninae39]

1. it moves weight away form the hitch
2. battery closer to the control, thus lower power loss
3. battery goes into dead space, ie not suitable for other uses

Lead acid go outside as they need vent
Li On do not vent

[SilverHouseDreams]

Originally Posted by NoResults

I am confused as to why most everyone here wants to install their new batteries inside. It would seem they put a battery box on the outside for a reason.

Freezing temp? No if it is freezing out it is probably freezing in. Putting them inside takes away from your storage.

The real reason they are outside is because lead acid batteries vent toxic gases and if/when they boil over it is best to have the sulfuric acid where it can do the least harm. Lithium (and other sealed) batteries change that, as they no longer are venting toxic/acidic gases that are destructive to human life and aluminum. Lithium additionally benefits from being within a climate controlled space, especially for freezing temperatures.

In my case I am installing the batteries into space that could otherwise really be used for anything at all...and I am gaining back storage space on the A-frame that will likely host a generator platform for transport in the future, which I absolutely would rather not have inside the trailer.

If you look at RVs and even some of the larger TTs, the batteries are more "inside" than just sitting within a plastic enclosure.

[SilverHouseDreams]

Originally Posted by waninae39

tnx .

i check when i get the as22fb out of storage. i know that area is VERY ting ht and i may have to remove the hinge platform and the mattress to do any serous work

i just ordered these off amazon to get ready for the spring. hopefully i will have a new battery by then also. hopefully before our first trip

It is tight, mine doesn't even have the hinged platform so I did it all through the tiny access panel in the top over the 12V power area, or by crawling through the door on the front of the storage space. Consider yourself lucky

I'll warn that the primary purpose of the Victron Battery Protect BP100 doesn't apply to BattleBorn. The BP100 is required for lithium banks with external battery management, it is required to disconnect the load if the state of charge gets "too low" or the cells are too cold to charge. Now it could be used in different modes, perhaps...but it will be outside of the primary targeted function. In the case of BattleBorn they use internal battery management, so internally the BMS will disable discharge when the SOC gets too low (or blocks charging when temperature is too low).

[bbandeddie]

Originally Posted by NoResults

I am confused as to why most everyone here wants to install their new batteries inside. It would seem they put a battery box on the outside for a reason.

Freezing temp? No if it is freezing out it is probably freezing in. Putting them inside takes away from your storage.

It’s not freezing inside when I’m camping in it!

[waninae39]

i got the bp100 to more easily disconnect the battery

btw my 2017 has a hinge and two gas cartridges to lift the mattress

also i call BB today and still no answer or call back

cheers

[waninae39]

you can get a good look into the area under the bed in a 22Fb in this video. he is installing solar, but there is a good view of the area

http://www.youtube.com/watch?v=9A3HHJ02iQs

[Rocinante]

One cautionary note: We're spec'ing out a solar / LFP solution with the folks at AM Solar, and they said that while they like Battle Borne batteries, the terminals are a different design from the other batteries they use - not bad, per-se, just different and as a result, you may need a bit more vertical space above the batteries if you're wiring multiple batteries in parallel. Be sure to take a look at this and ensure you're comfortable with that style of battery terminal.

[Gsmblue]

I broke down and ordered the new PD 4655VL from best converter. I noticed that my batteries were draining over time when hooked up to shore power as they are never truly isolated.

The SOC reading on my Victron monitor is saying I only have 90% of the capacity available to me in the battery bank. I am not sure why.. The batteries were in stalled in August and the SOC was calibrated then for 100% at 198Ah.

I am thinking installing a isolator between the batteries and the Victron shunt will be a good idea, just not sure there is actually a good location to do that!

[SilverHouseDreams]

Originally Posted by Gsmblue

I broke down and ordered the new PD 4655VL from best converter. I noticed that my batteries were draining over time when hooked up to shore power as they are never truly isolated.

The SOC reading on my Victron monitor is saying I only have 90% of the capacity available to me in the battery bank. I am not sure why.. The batteries were in stalled in August and the SOC was calibrated then for 100% at 198Ah.

I am thinking installing a isolator between the batteries and the Victron shunt will be a good idea, just not sure there is actually a good location to do that!

It may only show 90% capacity if you are using a non-lithium converter/charger, as they are unlikely to ever keep the voltage high enough to reach 100% SOC in a reliable fashion. If you have a converter that can be forced into "boost" mode then you could trigger boost mode and see if the SOC reaches 100%, however since the lead acid charge profile switches to "float" or "standard" based on time and or target voltages that are below 14.4V you won't ever have 100% SOC by default.

I'm not sure why one would want to disconnect the Victron BMS, other than for very long term storage without any power coming into the batteries...but then you would want to disconnect the propane detector too, which would likely be achieved by that. If you have solar and store it outside, then there is likely no need to do so though. It would only be for long term storage with no charging to maintain SOC and offset the parasitic load of the BMV and propane detector.

What you are seeing is that the "standard" voltage of your converter is lower than the resting voltage of the batteries. So once the converter drops to "standard" or "float" mode the 12V power source is going to be whatever has the higher voltage output, and that is your BattleBorn batteries as they rest at >13.6V and respond to load very readily...so the converter never detects a load to actually transition out of "float". Of course if you have an old single-stage converter then this changes things slightly, however that standard voltage level is still likely below 100% SOC for the BattleBorn.

[Gsmblue]

I store my Airstream in my RV garage attached to my house, actually it is kinda in my living room! I keep the trailer hooked up to shore power as I like to work from the airstream instead of my home office..

I understand the 14.4V vs the 13.6V battery/charger issue. I do hit the boost on my PD4655 but over time (8 months) the SOC has dropped from 100% to 90%. So i am not sure if this is a real issue or not. I am not sure how to go about a true capacity test - I probably don't even really need to worry about it either as I don't boondocks for more than a couple of nights and I have 200W of solar and a 3.1Kv genny..

Any which way, I will be changing the converter/charger out for the new PD4655 with the Li jumper to keep it at 14.4V. I will see how that works out before putting in a battery disconnect on the -Ve side.

Basically, I do not want to damage/degrade my batteries...

[SilverHouseDreams]

Originally Posted by Gsmblue

I store my Airstream in my RV garage attached to my house, actually it is kinda in my living room! I keep the trailer hooked up to shore power as I like to work from the airstream instead of my home office..

I understand the 14.4V vs the 13.6V battery/charger issue. I do hit the boost on my PD4655 but over time (8 months) the SOC has dropped from 100% to 90%. So i am not sure if this is a real issue or not. I am not sure how to go about a true capacity test - I probably don't even really need to worry about it either as I don't boondocks for more than a couple of nights and I have 200W of solar and a 3.1Kv genny..

Any which way, I will be changing the converter/charger out for the new PD4655 with the Li jumper to keep it at 14.4V. I will see how that works out before putting in a battery disconnect on the -Ve side.

Basically, I do not want to damage/degrade my batteries...

If you manually trigger boost does the SOC go back up to 100%? I suspect it would, or at least get very close to 100% SOC.

As for actually testing capacity, in my case I can just switch my 3-mode refrigerator to DC mode and it can pull it down. You would want to get the SOC to 100%, so if the manual "boost" mode achieves it then you are set. You would want to disconnect shore power and leave all of the your DC load on to slowly drain it down, since you have an inverter you could always hook up a hotplate or a space heater to quickly draw down the power. You'd then just watch the Victron BMV status to see how many Ah it actually reports being drawn from the battery bank.

As for destroying your batteries, it is likely the case that your battery "life", that comes down to how the battery cell balancing system works. If it was a 100% balanced group of cells, only charging to 90% SOC the majority of the time (and 100% on occasion) should actually extend the total life of the batteries. However the BatleBorn (and most battery management systems, or BMS, for our use) only truly balance on charging, and that really applies as SOC approaches 100%. So your concern is likely valid as the individual cells age, not charging to 100% SOC could result in a couple of cells slowly lagging and that could cause the BMS to disconnect the output of the bank to protect from under voltage of those cells.

[JayTheCPA]

Glad to see that I am on-track in terms of open questions when hooking to the TV.

Will follow-up in the other thread.

From a perspective of bonus application for the lithium's, if I can fully solve the TV equation, this has promise to put a dedicated inverter in place to run the fridge on A/C while towing versus gas. Actually, for my current towing distances I just turn off the fridge rather than entertain risks with tilting or blow-outs. But this is another topic . . .

[waninae39]

you my be interested in these 100 Amp Schottky Diode
these have a low forward voltage drop and a very fast switching action

learn more here
https://en.wikipedia.org/wiki/Schottky_diode

order the diode here for $8 each

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[larry9000]

Originally Posted by waninae39

you my be interested in these 100 Amp Schottky Diode
these have a low forward voltage drop and a very fast switching action

Thanks for the link!

This is an easy fix for those not wanting to get a real DC-DC converter. I plan to get a DC-DC converter in the future, but I think I'll order one of these as a quick fix for when I pull the TT out of storage. The advantages of the diode is ease of installation and cost. If the lithium house battery is low, the alternator can recharge it, as long as the TV voltage is above the TT voltage by at least the threshold voltage of the diode. (.155 to .37 volts up to 50A). This will help you out in a pinch if you find that the house battery was deeply discharged during a camping trip, for instance. If the lithium battery has a higher voltage than the TV battery/alternator, no current flows back, solving the discharge issue.

The advantage of a DC-DC converter is all of the above, plus it will completely charge a lithium battery even if the TV battery voltage is lower.

[mythbuster88]

Originally Posted by larry9000

Thanks for the link!

This is an easy fix for those not wanting to get a real DC-DC converter. I plan to get a DC-DC converter in the future, but I think I'll order one of these as a quick fix for when I pull the TT out of storage. The advantages of the diode is ease of installation and cost. If the lithium house battery is low, the alternator can recharge it, as long as the TV voltage is above the TT voltage by at least the threshold voltage of the diode. (.155 to .37 volts up to 50A). This will help you out in a pinch if you find that the house battery was deeply discharged during a camping trip, for instance. If the lithium battery has a higher voltage than the TV battery/alternator, no current flows back, solving the discharge issue.

The advantage of a DC-DC converter is all of the above, plus it will completely charge a lithium battery even if the TV battery voltage is lower.

Just sayin'...not a lot of difference between inserting a diode in series will your tv (putting it on a isolated heat sink etc), and just inserting a dc/dc converter.

[waninae39]

the diode is very better. less than $10 and only one items

the DC - DC is higher price plus it is a system that may have a problem

that's why i'm going to use the diode instead.

even if the trailer is higher that the TV, the diode will NOT send power that way. it will only send power one way

[daleyocum]

Originally Posted by waninae39

you my be interested in these 100 Amp Schottky Diode
these have a low forward voltage drop and a very fast switching action

learn more here
https://en.wikipedia.org/wiki/Schottky_diode

order the diode here for $8 each

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Alas those are only good to 15v, calling it a little close given the charge voltage can be that high.

[larry9000]

Originally Posted by daleyocum

Alas those are only good to 15v, calling it a little close given the charge voltage can be that high.

Here is the link to the complete data sheet:

http://www.irf.com/product-info/data.../100bgq015.pdf

Good catch.

The 15V is the max reverse voltage, which is TT voltage - TV voltage. We would only approach this if TV battery was dead. I think this spec is OK. Also concerning is the reverse current spec, IRM, which can approach one Amp at high junction temperatures. After all, no diode is a perfect diode. This is the amount of current that can flow from TT to TV even when TT voltage is higher. It's minimal at low TJ (Junction Temperature), but very high at high TJ. A good heat sink will keep the TJ lower, but then the installation is more difficult.

With my 10 AWG charging wire coming from the TV, I probably will never charge the Lithium battery at more than 10 Amps. (I've measured 4A at peak alternator voltage). Assume a 0.35 V forward diode drop, then only 3.5 watts is dissipated in the diode. This is low enough to avoid using a heat sink (I think). But the size of the junction is pretty small, and even those 3 watts may heat it up nicely.

I may still give it a try. The times I might get a higher TJ due to the power dissipated above is when the TV is charging the TT. I don't need to worry about IRM in that case, as there is no reversed voltage. If TT voltage is greater than TV voltage (the situation where IRM is important), there will be almost no power dissipated in the diode, so it shouldn't be seeing a higher junction temperature.

The only scenario where I can see this could be a problem is just as the TV alternator slows down after some minutes of driving. This is the situation I saw with my 4Runner. In this case, the TJ is elevated due to charging the TT. When the TV voltage drops a bit due to alternator slowing, the diode becomes reversed. It is still warm from the charging current. There is some risk that IRM could be significant here. However, two things are occurring that help us. One, the diode itself will cool due to lack of power dissipated, so it's a temporary situation. Second, the reverse voltage isn't very much. Maybe a volt. This reduces IRM too.

The diode MAY work, or may not. If I have to use an isolated heat sink, I may as well go to the DC-DC converter, as I will already have a more significant installation.

[waninae39]

i have two diode

100A and 30V in serial and not parallel

[waninae39]

i also bought a box of TO-220AC Schottky Barrier Rectifier 100V 20A
five of them in parallel will work
$20 for 50 in Amazon today