Inaccurate Replacement Lithium Converter Information from Battle Born Batteries

[Guest]

So, Sometimes my mind runs amok with Rube Goldberg ideas. I know this is a little off track from the original post. But why haven't I ever seen anyone mount their travel trailer batteries on the roof? With the LiFePO4 batteries only weighing 29 pounds, you could put four of them in an appropriate tool box on the roof. Sure, it would be fun to figure out all the wiring, but four of those batteries would weigh less than one air conditioner.

Jim

Jim,

For being out in the hot zone, mounting batteries under the rig may also be an option. Perhaps a sliding battery tray or vented metal box on a slide?

Jim

[Second Chance]

Interesting Rob.

I see that WFCO states their model is for Lithium Ion batteries. Whereas Progressive Dynamics states theirs is for LiFePO4 batteries. Personally, i would never install a lithium ion battery in my RV due to the risk of fire.

One other aspect. PD's charger charges at a continuous 14.6VDC, and throttles back the current as the LiFePO4 batteries near full charge. The WFCO version throttles down the voltage to 13.6 which is very similar to the profile a Lead Acid charger has.

Prices for the WFCO model run about $35-$40 less than the PD model.

Jim

Jim,

I just received the following info back from Battle Born regarding the WFCO WF-9850L2:

Hi Rob,

That converter has a Lithium profile and will work with our batteries. When checking product compatibility you just want to make sure the converter/charger meets these requirements:

Bulk/absorb 14.2 - 14.6 Volts(we usually recommend 14.4)
float 13.6 Volts or lower
No equalization(or set it to 14.4v)
No temperature compensation
Absorption time is 20 minutes per battery(if it is an option).

Your WFCO WF-9850L2 meets these parameters.

Rob

[Guest]

Rob,
What do they mean by not using temperature compensation? In extreme hot or cold, the charge rate should be reduced or stopped completely. How does BB suggest folks do this? Perhaps they rely solely on their BMS?
Jim

[Second Chance]

Rob,
What do they mean by not using temperature compensation? In extreme hot or cold, the charge rate should be reduced or stopped completely. How does BB suggest folks do this? Perhaps they rely solely on their BMS?
Jim

You'll have to ask Battle Born as I don't know the answer to this question. I have ordered heating pads along with my batteries in order to avoid the cold-weather charging problem.

Rob

[Guest]

Rob,

The heating pads would work well. Do they incorporate a thermostatic control? Goes back to wanting to put the battery under the bed but the DW was really protesting on this one. If I expected to ever eat again I needed to cave in. LOL. The charger I'm intending on purchasing has an option to monitor temperature so it does not have to be used if a BB were to be used. I will ask them about adjusting charge based on battery temperature.

Jim

[Second Chance]

Yes - thermostatically controlled:

https://battlebornbatteries.com/shop...d-for-bb10012/
Since LiFePO4 batteries don't have to be vented, I could also put them behind the divider wall in the heated part of the basement in the fifth wheel... but I don't want to re-route all the heavy wiring.

Rob

[howson]

Rob,
What do they mean by not using temperature compensation? In extreme hot or cold, the charge rate should be reduced or stopped completely. How does BB suggest folks do this? Perhaps they rely solely on their BMS?
Jim

You'll find this video informative:

[Guest]

Howard,

Thank you. I've seen this video.

Temperature compensation is the main reason I am going to purchase the AIMS charger and battery but I will contact BB to get their feedback on their not using this. Or they want to be sure for chargers in the same location as the batteries with internal compensation in the charger not be used? The AIMS charger has the option to monitor battery temperature where the battery has an integrated sensor. Its not a requirement. The AIMS charger will also automatically start a generator which for me is not a requirement but I will see if it can be integrated.

When I see you at the next rally I will share a story in taking a hybrid to a dealer in Dillion Co. for a 12V AGM battery replacement. The high voltage lines on a hybrid are always bright orange....and 300V in this case.

Jim

[TucsonJim]

Jim,

Thanks...this is a nice video. I'm leaning heavily on the AIMS charger that will adjust the charge rate for both hot and cold where it uses a battery temp sensor to make adjustments. AIMS recommendation on storage is at 50% SOC where I've always done this with my Lithium batteries for other hobbies. In the video, they recommend to fully charge the battery and to rely on a self discharge which would settle in at 50%. But I would still run the BB born battery down on a trip and do my best to store it at 50% SOC rather than to let it self discharge. Cell life is maximized at storage levels at 50% SOC and also to reduce the DOD.

I was going to install the battery under the bed since it would be far more stable in temperatures that we ourselves would prefer, but the wife protested on this....Lol. So its going to be mounted out on the tongue.

Jim

Jim - I'd never seen the recommendation for storing LiFePO4 batteries at a 50% SOC. So I did a little research on the Battle Born website, and they have a short video on the FAQ section about winterizing their batteries for long term storage. They recommend disconnecting at a full 100% SOC.

Do you have any articles you can point me to for the 50% SOC recommendation? I'd love to discuss this with the Battle Born guys.

https://battlebornbatteries.com/faq/...ize-batteries/

Jim

[Guest]

Jim - I'd never seen the recommendation for storing LiFePO4 batteries at a 50% SOC. So I did a little research on the Battle Born website, and they have a short video on the FAQ section about winterizing their batteries for long term storage. They recommend disconnecting at a full 100% SOC.

Do you have any articles you can point me to for the 50% SOC recommendation? I'd love to discuss this with the Battle Born guys.

https://battlebornbatteries.com/faq/...ize-batteries/

Jim

Jim,

AIMScorp suggests long term storage at 50% SOC. Lithium batteries tend to age more if kept at their extreme end points so for long term storage a nominal SOC at 50% is the norm and is widely used. For our RC batteries which can be quite large in capacity, we store them at 50%. I have a high end smart charger that has charge, cycle, balance and storage functions. In the BB video they mention their battery will self discharge and will stabilize at 50% SOC. I've not heard this before so maybe there is something to learn in how they do this. For auto's as general information, the battery has far more capacity in reserve where its kept in a fairly narrow operating band to provide long life. Then as capacity begins to fall due to age, additional modules are turned on in order to keep the claimed mileage in check over time.

Jim

[Guest]

Jim,

Here are a couple articles in general care of various lithium battery types. Also attached is the AIMS battery manual where they specify to store at 50% SOC. Its interesting that some folks are claiming storage at 40%-50% SOC to be ideal. I always targeted 50%. A charger with selectable SOC, DOD and Storage modes would be great for these larger capacity batteries, but I've not found one.

https://batteryuniversity.com/index....ased_batteries

https://batteryguy.com/kb/knowledge-...sed-batteries/

Aims_LFPBattery Manual 3-26-2019.pdf

Jim

[JeffC]

So that brings up the question of solar charging. We keep our batteries online with our solar controller maintaining charge while in storage. We see the normal parasitic drops in the morning and back to topped off in the afternoon. Is this not a long term solution?

[TucsonJim]

So that brings up the question of solar charging. We keep our batteries online with our solar controller maintaining charge while in storage. We see the normal parasitic drops in the morning and back to topped off in the afternoon. Is this not a long term solution?

I just contacted Battle Born and requested they answer your question along with the recommended storage state of charge question. I'll share the information when I get the response.

Jim

[TucsonJim]

Guest et.al.

Jim - I was able to pose a couple of questions to the Battle Born guys and received a prompt response from them. I asked about the desired SOC for the batteries along with the recommendation of using solar to keep up with parasitic loads. Here was their response:

"Jim,

Thanks for your email.

When prepping for a prolonged storage period we recommend a 50% SOC at a minimum. The closer you can get the charge to 100% SOC the better we feel. The rationale behind this is our low discharge rate. The battery only loses 2-3% capacity per month while stored, so we feel that anything above 50% can allow safe storage for 6+ month periods.

There is no issue if the solar is left connected to the batteries to allow a charge to occur to replace any parasitic draw. A lot of our customers like to disconnect the battery from the system due to the maintenance free aspect of our batteries. Disconnecting means the system does not need to be worried about while stored. It is possible keeping the solar connect could mean the battery could perform a number of cycles while stored which could shorten the overall life of the battery, albeit very marginally. I hope this helps answer some of these ongoing discussions on the board.


Best,

Eric Carter
Battle Born Batteries
855-292-2831"

Jim

[Guest]

Guest et.al.

Jim - I was able to pose a couple of questions to the Battle Born guys and received a prompt response from them. I asked about the desired SOC for the batteries along with the recommendation of using solar to keep up with parasitic loads. Here was their response:

"Jim,

Thanks for your email.

When prepping for a prolonged storage period we recommend a 50% SOC at a minimum. The closer you can get the charge to 100% SOC the better we feel. The rationale behind this is our low discharge rate. The battery only loses 2-3% capacity per month while stored, so we feel that anything above 50% can allow safe storage for 6+ month periods.

There is no issue if the solar is left connected to the batteries to allow a charge to occur to replace any parasitic draw. A lot of our customers like to disconnect the battery from the system due to the maintenance free aspect of our batteries. Disconnecting means the system does not need to be worried about while stored. It is possible keeping the solar connect could mean the battery could perform a number of cycles while stored which could shorten the overall life of the battery, albeit very marginally. I hope this helps answer some of these ongoing discussions on the board.


Best,

Eric Carter
Battle Born Batteries
855-292-2831"

Jim

Jim,

For the first line in bold, I believe BB is more concerned about allowing a complete discharge and sitting for a long period of time in this state which would shorten battery life. I also asked them if I targeted 50% from a lower SOC and monitored closely, would I gain battery life by not waiting on the self discharge which could take months. I believe yes is the answer. I'm waiting on their response to this question.

For the solar Q&A, the battery is being exercised so if it were me, I would store at a lower SOC such as 50% (waiting on their reply), disconnect the negative battery cable and monitor closely. As they stated in their video, the batteries will stabilize and stay at the lower SOC for a long time so to target a lower SOC, and monitor SOC, makes good sense to increase battery life.

I'm sure BB is a great battery but the chemistry and even the cell manufacture most likely is the same as the other batteries out there where the recommendation varies a bit from BB. They are the only ones who are stating to store at 100% SOC.

Storage temperature is also important but I did not ask this question since I am out east and would bring the battery inside for winter storage.

Thank you Jim in checking with them. I purchased my charger and after paying a ton of medical bills that have not come in yet, I will order the battery.


Jim