Battle Born lithium batteries

[DuffMan]

This is what I did, but I didn't apply the heating pad directly to the batteries. Instead, I placed the heating pad under a thin sheet of aluminum that was the base of my battery frame. This helps dissipate the heat and more evenly warm the batteries. It also kept the batteries from rubbing on the blanket and possibly shorting things out. Finally, having the pads under the batteries allows the heat to rise, making them more efficient.

[DriverDon]

That all sounds like very sound thinking! I hope you don't mind me copying you...

[swmurray]

Hi: i don't want to hijack the thread, but have a similar plan to swap out batteries and wanted to ask a few installation questions to make sure I do it "right".
We are new to RVing and this forum. If I need to post separately I'll gladly do so - Thanks!

We have a new Solitude 310GK-R with two standard 12V batteries in the plastic storage cases (dealer supplied). The unit has the stock WFCO inverter, converter, and a T-57 transfer switch (generator prep). We are not planning to boondock yet, but hope to build up to this later. Currently we want to charge the batteries enough to keep the residential fridge going while driving for 1-3 days between destinations. Hopefully any changes now will be transferrable to a future boondock/solar set-up.

1) How do we mount the BB batteries? Should they be installed in the existing cases or mounted directly? How to best secure the batteries and protect the terminals? Do we need different battery wiring - size?
2) Do we need to change out any of the inverter/converter equipment to go Li? (I don't think so because the BB batteries have their own BMS built in - correct?)
3) Does the stock battery charge indicator in the RV panel work with the Li batteries to show remaining power level? (I would not think so due to the different voltage curve - what is recommended to monitor battery level?)
4) Will the standard 7-tab connection provide enough power to keep the batteries charged for 1-3 days of driving and keep the residential fridge cool? If not, what do you suggest? There is a second t-tab connector on the truck, but not sure were to plug in for RV.
5) Will 2 BB batteries (standard 100AH size) be adequate? We would use the fridge to store and grab snacks for the drive as compared to our normal Igloo cooler.
6) Should we include heated pads for the batteries if we expect some nights to be below 32 degF?
7) Any issues I missed?

Thank you in advance!!!!

[DuffMan]

Hi: i don't want to hijack the thread, but have a similar plan to swap out batteries and wanted to ask a few installation questions to make sure I do it "right".
We are new to RVing and this forum. If I need to post separately I'll gladly do so - Thanks!

We have a new Solitude 310GK-R with two standard 12V batteries in the plastic storage cases (dealer supplied). The unit has the stock WFCO inverter, converter, and a T-57 transfer switch (generator prep). We are not planning to boondock yet, but hope to build up to this later. Currently we want to charge the batteries enough to keep the residential fridge going while driving for 1-3 days between destinations. Hopefully any changes now will be transferrable to a future boondock/solar set-up.

1) How do we mount the BB batteries? Should they be installed in the existing cases or mounted directly? How to best secure the batteries and protect the terminals? Do we need different battery wiring - size?

Almost ANY mounting setup will work with BB. They are sealed and do NOT off-gas, so mounting on the floor of your storage compartment, in a self-made rack, under your bed, etc. are ALL acceptable options. Make sure they are secure (won't move around while traveling), protected from damage (nothing will hit it while traveling), protected from abrasion (no hard contact points on your battery mounting frame), and feel free to mount them upside down if it works better for your situation. Just make them secure and protect from damage.

2) Do we need to change out any of the inverter/converter equipment to go Li? (I don't think so because the BB batteries have their own BMS built in - correct?)

Short answer: No. Long answer: Maybe. Although BB is designed to be a "drop-in" replacement and they will work perfectly fine on a standard charger, you will get more performance and life from replacing your converter with something that is lithium-aware. You can do even better with a unit that can be programmed to the EXACT parameters that BB would like. Again, drop-in and use is fine... upgrade your converter for maximum performance though.

3) Does the stock battery charge indicator in the RV panel work with the Li batteries to show remaining power level? (I would not think so due to the different voltage curve - what is recommended to monitor battery level?)

No. In fact, it'll be showing your full/almost full right up until you have "dead" lithiums. Lithium batteries operate at higher voltages, so your stock battery condition indicator is almost useless when you switch. I HIGHLY recommend getting a SoC (State of Charge) indicator that can be programmed to your lithium battery parameters and uses a shunt resistor on the negative side. Victron is my personal favorite (BMV-700 series) with the BMV-712 with bluetooth being the nicest... and priciest.

4) Will the standard 7-tab connection provide enough power to keep the batteries charged for 1-3 days of driving and keep the residential fridge cool? If not, what do you suggest? There is a second t-tab connector on the truck, but not sure were to plug in for RV.

You will have issues charging with your truck alternator. As stated above, the voltages are higher... consequently the alternator doesn't see the lithium as "down" in the same way as a lead-acid. My personal experience in this arena is limited, but I know you will want a battery isolator that prevents the lithium from pulling too much current from your alternator and hurting it.

5) Will 2 BB batteries (standard 100AH size) be adequate? We would use the fridge to store and grab snacks for the drive as compared to our normal Igloo cooler.

This is a simple math problem and your unit will be specific to you. You need to determine how much current you are pulling (amps) and multiply that times the number of hours you are wanting to run those loads to determine how many "amp hours" you need to accomplish the task. This is HIGHLY simplified, but will get you in the ballpark.

6) Should we include heated pads for the batteries if we expect some nights to be below 32 degF?

No, not unless you plan to spend time in sub-freezing temps, the batteries are directly exposed to those temps, and will want to recharge them while staying in those temps. Lithium can be DISCHARGED while below freezing, but cannot be charged low freezing. BB actually protects against this. That said, I wouldn't hesitate to add a little bit of protection against the unplanned cold, by adding a heating pad to the compartment floor and using a switch to turn it on when the temps get really bad.

7) Any issues I missed?

I think you hit on most of them. The only thing I can think of is cabling. Since your rig will not pull any more current than it previously did, and your converter will not charge with any more current than it previously did, your stock battery cables are sufficient. However, if you add something like a large inverter, you will want the appropriate cabling going directly to the batteries from the inverter. Also, if you added a high-current charger for the lithium, you would want to upgrade the cables between the charger and the batteries. Finally, don't forget that the cables that tie the batteries together (typically in parallel) MUST be as heavy as your heaviest load cable.

Good luck and I hope this helped!

[swmurray]

Duffman: Thank you, Thank you for the detailed reply!

I'll look into the SoC indicator and upgrading the stock (WFCO) to a Li-aware model. (I know I need to find out the capacity of the stock one). I don't have access to the RV yet so will need to investigate further what's where and figure out the wiring diagram.

i wasn't aware of a possibility of overloading my truck alternator. Where might I learn about the battery isolator and how these circuits interconnect?

Thank you.

[DuffMan]

The capacity of the stock converter isn’t really an issue. Look for a li-aware charger that will charge about 50 or so amps. That will be pretty good for 2 BB batteries, although they are capable of taking double that. It’ll also be plenty to handle the normal loads of the RV.

The SoC indicator will be wired separately and not tied to the stock setup at all. Just leave it stock and add the Victron for accuracy.

If you look on BB’s site, they talk about charging from vehicle and have the isolator. It disconnects after a set period of time to allow the alternator to “rest” for a bit and then reconnects to continue charging. Here is a link: https://battlebornbatteries.com/shop...ation-manager/

[orbiker]

The capacity of the stock converter isn’t really an issue. Look for a li-aware charger that will charge about 50 or so amps. That will be pretty good for 2 BB batteries, although they are capable of taking double that. It’ll also be plenty to handle the normal loads of the RV.

The SoC indicator will be wired separately and not tied to the stock setup at all. Just leave it stock and add the Victron for accuracy.

If you look on BB’s site, they talk about charging from vehicle and have the isolator. It disconnects after a set period of time to allow the alternator to “rest” for a bit and then reconnects to continue charging. Here is a link: https://battlebornbatteries.com/shop...ation-manager/

I'm trying to understand the purpose of the battery isolator.
Looking at the battery isolator you linked, it has big poles for the chassis battery and the coach battery. It seems to me, that is for a motorhome or class C.

Thanks, KEN

[DuffMan]

I had to go back and look myself. I made up a wiring diagram after talking to BB about this issue a couple years ago. Here is what I have:

The attachment to the chassis battery is where the charge comes from. The rest is control and of course charge going to the BB. This device charges for 15 min and then lets the alternator rest for 20 to save burning it up. A dead lithium will take every bit of current your alternator puts out... which will overheat it if done continuously.

P.S. This is best looked at by thinking of your charge circuit as a separate line, not the 7-spade connection. With the possibility of pulling a couple hundred amps, you would want to run separated ground and positive lines for maximum efficiency and safety. I know my truck can put out 200 amps from the alternator, so a separate line with Anderson connectors will be in my future as I build the lithium setup on this rig. In some ways, it is more hassle than it is worth, but it can be done. With a good charger and a short generator run every couple days, you can easily replenish your lithium. And remember; unlike regular batteries, lithium do NOT require a full charge to be used again. You can theoretically drain to 20% and recharge to 80% for a year without damaging them or shortening their life.

[swmurray]

Duffman:

Thank you again for the guidance.

My hope was to drop in a couple of Li batteries (with internal BMS) to add enough power storage to keep refrigerated items cool for 2-3 days of driving between points, with the expectations that I'd build a more boondock-ready system as I learn more. Clearly I have some homework to do before any changes!!!

Thank you!

[DuffMan]

Honestly, I think you will be close. You may get a little bit of charge through the 7-spade, but I would focus on having enough batter capacity to get through your travel days with the fridge running. Remember, it doesn’t run constantly, so you don’t need the worst-case draw times 24, you need that times the duty cycle. So, if it runs for 15 minutes every hour, you need about 6 hours worth each day. Don’t forget to add in the current draw from other items when the fridge isn’t running.

If you don’t have enough capacity in 2 BBs, you may just consider running the generator for an hour each night. With a high current charger, you could replenish 50-100 amp(hours) in just an hour of charging.

Feel free to ask other questions. This helps me keep the info fresh as sometimes makes me dig into a portion of the topic I am weak on and learn more.