Anyone put lithium batteries into their Bambi?

[larry9000]

Thanks Sandy,

Ah- you had the trailer prewired for the Zamp connector- so you already had both wires. I'll have to check mine if I can get an extra wire into the cabin. However, in the mean time, I checked the specs on the Victron battery management system you had shown. Sweet. Most importantly, I think I could use a single power wire for the hitch and as a point of charge for an external panel. Doing so requires another solar controller up front (in a waterproof enclosure), but it is a good plan B if I can't get an extra cable into the cabin. The Victron shunt will measure the charge regardless where it is coming from.

BTW, those of you who have the original Sun Explorer (Atkinson) solar charger like I do, the Victron monitor MAY have another advantage. The Sun Explorer display is remotely mounted, through a phone jack cable, it appears. So is the Victron! This means you can mount the Victron in the galley where the Sun Explorer system display was. At least, that is the plan...

[ateric1]

Lots of good stuff Sandy, thanks. I have a question for those that have run new 6 gauge wire. I see where its on the roof and to the front of the camper. Is there enough slop that you can attach the 6 gauge to the existing wires and then pull it through? Or do you have to remove panels to run new wire?
Thanks in advance.
Eric

[larry9000]

Well, I pulled the trigger, and ordered all the parts, including a battery for a lithium system. I'm following many of the details used by SanAndVin. Same battery and mounting location- with long enough cables to pull battery out for servicing the area. Same Zamp solar controller. Same Victron battery monitor, However, for the later, I'm putting a remote display by the other controls next to the galley. Finally, I'm upgrading my factory 50W solar system to 2 100W panels, in tandem on driver's side of trailer.

I changed the converter before anything, to a PD 4655, to get the 14.4 charging voltage needed for lithium, which is normally used as boost mode for AGMs.

I've hired a competent RV repairman to do the mechanical work, inside a covered garage. Once I get key parts of this finished, I'll post some photos.

Double the battery capacity, 4x the solar capacity, lower hitch weight. What's not to love?

[MsTara]

Following with great interest.

I carry a 400 Goal Zero in the cabin for charging all my electronics. But, my outside coach battery is pitiful in how long it charges. I LOVE these ideas, but nervous about what it would take to move the wires from the outside battery to the inside battery? Note, I am not electrically inclined at all!

[SanAndVin]

Well done Larry9000. To follow up on our battery/solar installation:
Since I last wrote, we took our Bambi on a three-week trip boon docking half of the time. We spent 7 days in Yellowstone without hookups and the weather often cloudy. Our rig was partly covered by pine trees so the sun power was limited. Even though the power conditions were not optimal we did great. Between the rooftop solar that successfully did collect some energy daily, and the effectiveness of the lithium battery, we had all the power we needed, and then some. A little admission here, we did not try to use the microwave while boon docking. All systems were a-go everyday using the heater, water pump, refer fan, etc. All the work making the modifications and additional equipment was worth the effort. Best trip ever.

Our hitch weight is so low now we had to place some tools in the old abandoned battery box in order to balance overall trailer weight front to back.

[SilverHouseDreams]

I have a 2011 22FB, I installed a BattleBorn 100Ah lithium battery and placed it under the bed between where the water heater is and the 12V wiring. This is wasted space, and any "heat" from the water heater will be a bonus in winter and won't cause any harm in summer...as the battery may actually even work "better" up to nearly 140-degrees F (60 degrees C) per the research I've read on the cell chemistry.

I just today received my new power converter, if you look in the battery discussion area you will find my detailing on the issues I found. The summary is that it is misleading to believe that these are "drop in replacements" with any existing converter/charger. The fact is that you will likely never get the battery to charge consistently, and those of us with 3-stage converters even have a worse chance. It will be a glacially slow process and will never get 100% full capacity, you would have to somehow force/trick it into "bulk" mode...but you will have a hard time even getting it out of the 13.2V mode until the battery is nearly 0%. Those that have a Charge Wizard will have to manually put it into the boost/bulk mode every time they want to charge, and they may find that even while plugged into shore power the battery will actually be powering everything in the trailer (and not the converter).

I will write up more details on my finding soon, I will be installing the newest version of the PD4655 very soon. This model isn't detailed anywhere, it features a jumper to disable the "Charge Wizard" and instead will work only for lithium batteries like the other lithium optimize Progressive Dynamic converter/chargers, however this one is a drop in replacement for our converters in the power center.

[Rpatrick16]

Originally Posted by larry9000

Well, I pulled the trigger, and ordered all the parts, including a battery for a lithium system. I'm following many of the details used by SanAndVin. Same battery and mounting location- with long enough cables to pull battery out for servicing the area. Same Zamp solar controller. Same Victron battery monitor, However, for the later, I'm putting a remote display by the other controls next to the galley. Finally, I'm upgrading my factory 50W solar system to 2 100W panels, in tandem on driver's side of trailer.

I changed the converter before anything, to a PD 4655, to get the 14.4 charging voltage needed for lithium, which is normally used as boost mode for AGMs.

I've hired a competent RV repairman to do the mechanical work, inside a covered garage. Once I get key parts of this finished, I'll post some photos.

Double the battery capacity, 4x the solar capacity, lower hitch weight. What's not to love?

I would guess your "wallet is even lighter"!

[larry9000]

Originally Posted by Rpatrick16

I would guess your "wallet is even lighter"!

Yes, the lithium battery was expensive, but everything else is the same cost as an AGM-based system. And, even with all the costs, it sure beats getting a new TV if the hitch weight exceeds 500 pounds!

[larry9000]

Originally Posted by SilverHouseDreams

I have a 2011 22FB,
I just today received my new power converter, if you look in the battery discussion area you will find my detailing on the issues I found. The summary is that it is misleading to believe that these are "drop in replacements" with any existing converter/charger. The fact is that you will likely never get the battery to charge consistently, and those of us with 3-stage converters even have a worse chance. It will be a glacially slow process and will never get 100% full capacity, you would have to somehow force/trick it into "bulk" mode...but you will have a hard time even getting it out of the 13.2V mode until the battery is nearly 0%. Those that have a Charge Wizard will have to manually put it into the boost/bulk mode every time they want to charge, and they may find that even while plugged into shore power the battery will actually be powering everything in the trailer (and not the converter).

I will write up more details on my finding soon, I will be installing the newest version of the PD4655 very soon. This model isn't detailed anywhere, it features a jumper to disable the "Charge Wizard" and instead will work only for lithium batteries like the other lithium optimize Progressive Dynamic converter/chargers, however this one is a drop in replacement for our converters in the power center.

I ordered the PD4655 in early August, so I got the "pre-lithium" model that requires the charge wizard to get to 14.4. I would have waited if I had known a lithium-specific model was coming out.

That said, as long as I can get the charge wizard to pump out the 14.4, I'm happy. We mostly use the Bambi boondocking, and we're putting 200W of solar on the roof to top them off.

[waninae39]

me too, i got the same PD model in aug

if i knew, i would have waited for the lithium version.
my unit only goes to 14.4v and most lithium need 14.6v

i called them and posted the cost in the battery area
http://www.airforums.com/forums/f449...es-162132.html

so far, its too much $$ for me to upgrade vs buy a new unit

[SilverHouseDreams]

To be clear, the lithium chargers may not actually got 14.6. Mine doesn’t and is within spec. 14.4V is 100% charged with 3.6V per cell. The only difference is in initiating charge or prolonged use on shore power.

[waninae39]

so

can i use my existing PD at 14.4?
do i have to change it to BOOST only mode? thus loose all the other modes.

i do not want to have to think about the batteries after i install them.
thus I do not want to change modes or think of how i use them

it would be like having to adjust the thermostat on the wall or in the fridge vs. letting it do its job.

BTW, other than battle born, all others need 14.6v
why do they stick with just 14.4v

i look forward to your detailed testing results in the batter forum

good work SilverHouseDreams

[SilverHouseDreams]

Originally Posted by waninae39

so

can i use my existing PD at 14.4?
do i have to change it to BOOST only mode? thus loose all the other modes.

i do not want to have to think about the batteries after i install them.
thus I do not want to change modes or think of how i use them

it would be like having to adjust the thermostat on the wall or in the fridge vs. letting it do its job.

BTW, other than battle born, all others need 14.6v
why do they stick with just 14.4v

i look forward to your detailed testing results in the batter forum

good work SilverHouseDreams

Sadly I won't get to do the full test that I was hoping for until next season, at this point. I was living on borrowed time having the AS parked in street parking in the city, and I got a tow warning that expired this past Saturday so I dragged it to a buddy's house about an hour away while I try to find more convenient storage. Convenient storage here has wait lists and costs a lot more than my buddy's place, so it may just stay there until spring since we have no desire to deal with our state's chain laws with a TT.

So a bit of detail here is that these batteries have an ideal charge state of ~3.6-3.65V. You can charge them higher than that, but really holding them higher than that for long term is likely not ideal. In fact if you look at the other application where these are used widely, in EVs...the battery management system is far more complex/intelligent and it varies the state of charge overtime, as you the user can't actually ever use the full capacity. They de-rate the capacity, how much varies from brand to brand...but this is why Tesla could do a software update to "add capacity" to those in storm stricken areas to give them a range boost.

I will try to get my full write up started soon with what I have now, the part I cannot do at this point is test and compare the day-to-day of using the Charge Wizard vs lithium mode converter. I can say that I predict that once your hit 100% charge and the converter goes into the 13.6V mode that your 12V gear isn't going to actually run off of the converter as the battery will have a higher state voltage than 13.6V. The 12V gear will draw from the battery until the voltage drops to the same voltage as the "normal mode" at 13.6V. Now, 13.6V is still considered close to 100% on the Battle Born battery (3.4V per cell) as the resting voltage is just slightly over that, I was seeing resting voltage ~13.7V. The Charge Wizard "equalize mode" that runs every 21 hours may boost it back up, or you would need to manually put it into Boost Mode.

What does this mean? That you may be giving up a couple % of total capacity when you switch from shore power to off-grid, unless you manually boost the battery beforehand. Will it matter? Probably not, unless you truly need every amp hour of capacity...but if you are driving for very long then it might boost back to absolute 100% from the TV anyhow (or solar).

PD doesn't fully detail the transition from Boost to Normal, they mention that it is either time based or when the bank hits 90% capacity (based on voltage test and lead acid curve?). If it truly switches to Normal mode immediately when it detects voltage is at 90% charge based on lead acid then it may not work well, it would be better for you if it was purely time driven. The good news is that LiFePO4 absorbs energy rapidly, so if it is time driven then feeding it at 14.4V with up to 55amps should bring it up quickly. In my case I've only seen a peak of ~28amps (again, didn't get time to test why only 28A)...but at 28amps it is replenishing nearly 28Ah per hour of charge, so in 3 hours that is nearly 84Ah of capacity restored to the battery.

It is really the "shore power" steady state that I am not clear on, but as long as it doesn't fall into "storage mode" you should be fine...but if it does drop to storage mode then that will allow the load to draw your battery down to 70% capacity. The fact that lithium batteries provide power so freely works against us (capable of a very high discharge rate relative to capacity) as the battery will provide the bulk of power and the converter may not detect load (this is what I witnessed with my original WFCPO 8955).

[larry9000]

I wanted to let people know that I have installed the 100A Battleborn battery into our Bambi, ala SanAndVin who led the way. I did the system design, while a great nearby RV mechanic, Kyle, did the installation. We put two AM Solar SP100 panels on the driver's side roof, going into a Zamp ZS-30A solar charger, and then to the BB, which we put under the dinette seat like SanAndVin. Kyle built a platform that the battery rested on, but with straps to pull the barrier completely out. We mounted the BMV 700 Battery Monitor on the galley wall with the other monitors,.

I am very happy with the system.

[SilverHouseDreams]

Originally Posted by larry9000

I wanted to let people know that I have installed the 100A Battleborn battery into our Bambi, ala SanAndVin who led the way. I did the system design, while a great nearby RV mechanic, Kyle, did the installation. We put two AM Solar SP100 panels on the driver's side roof, going into a Zamp ZS-30A solar charger, and then to the BB, which we put under the dinette seat like SanAndVin. Kyle built a platform that the battery rested on, but with straps to pull the barrier completely out. We mounted the BMV 700 Battery Monitor on the galley wall with the other monitors,.



I am very happy with the system.

Curious, are you still running the stock converter? You might want to rethink that if so, you can find my other posts in the subject. But as much as we want these batteries to be “plug and play”, they really aren’t if you want predictability in state of charge.

[larry9000]

Originally Posted by SilverHouseDreams

Curious, are you still running the stock converter? You might want to rethink that if so, you can find my other posts in the subject. But as much as we want these batteries to be “plug and play”, they really aren’t if you want predictability in state of charge.

I switched to the PD4655V just before they came out with the LV lithium version. I have that. My plan is to press the 14.4V boost mode on the Charge Wizard to give a final fill up before leaving a campsite that has electrical power.

The other thing I found out was not plug-n-play was the charge line from the TV. I ended up disconnecting it. The lithium battery would try to charge the TV battery through that line. I had made some measurements of alternator voltage etc. that convinced me it wasn't an issue, but it turned out to be one. When I connected to the trailer, there was no current, because that line is keyed to the ignition through a really. When I turned ignition on, but not starting the engine, 7-8 Amps would flow from the TT lithium battery to the TV battery. When I started the engine, the net flow was 4Amps the other way. I could see all this on the Victron battery management app. I had it running in the TV as I pull the trailer home. But the current slowly went the other way- to a net discharge. I don't know why this happened. It was if the alternator stopped pumping current. Anyway, after that, I decided to snip the TV charge line at the 12V bus bar. It's easy for me to add it if I need the TV to charge a dead TT battery.

[SilverHouseDreams]

Originally Posted by larry9000

I switched to the PD4655V just before they came out with the LV lithium version. I have that. My plan is to press the 14.4V boost mode on the Charge Wizard to give a final fill up before leaving a campsite that has electrical power.

The other thing I found out was not plug-n-play was the charge line from the TV. I ended up disconnecting it. The lithium battery would try to charge the TV battery through that line. I had made some measurements of alternator voltage etc. that convinced me it wasn't an issue, but it turned out to be one. When I connected to the trailer, there was no current, because that line is keyed to the ignition through a really. When I turned ignition on, but not starting the engine, 7-8 Amps would flow from the TT lithium battery to the TV battery. When I started the engine, the net flow was 4Amps the other way. I could see all this on the Victron battery management app. I had it running in the TV as I pull the trailer home. But the current slowly went the other way- to a net discharge. I don't know why this happened. It was if the alternator stopped pumping current. Anyway, after that, I decided to snip the TV charge line at the 12V bus bar. It's easy for me to add it if I need the TV to charge a dead TT battery.

Sorry, I think I probably knew that you had the PD4655 from previous discussions and it just didn't register on the mobile device. I found the same thing on the TV drain issue: http://www.airforums.com/forums/f449...rn-173827.html

I plan on doing more testing, I only noticed the TV drain when I was hooked up to take it to winter storage. I too would have been oblivious to it without my Victron BMS-712 telling me explicit detail about energy flow. It seems some of the possible solutions are: disconnect the charge line entirely (free), install a diode to only allow voltage flow one direction (low cost, bit of time), install a DC-DC voltage converter (Victron Orion-Tr 12/12-18 is ~$120).

[larry9000]

Originally Posted by SilverHouseDreams

Sorry, I think I probably knew that you had the PD4655 from previous discussions and it just didn't register on the mobile device. I found the same thing on the TV drain issue: http://www.airforums.com/forums/f449...rn-173827.html

I plan on doing more testing, I only noticed the TV drain when I was hooked up to take it to winter storage. I too would have been oblivious to it without my Victron BMS-712 telling me explicit detail about energy flow. It seems some of the possible solutions are: disconnect the charge line entirely (free), install a diode to only allow voltage flow one direction (low cost, bit of time), install a DC-DC voltage converter (Victron Orion-Tr 12/12-18 is ~$120).

Thanks for reminding me of that link. I just posted my experience for those who were reading that thread. For now, I have a solution that "works". If I can find the space I may add the DC-DC converter next year when I take the Bambi out of winter storage.

Overall, I met my objective. I reduced hitch weight by 30 pounds, bringing me comfortably under my Toyota's hitch weight limit. My usuable battery capacity is double of the AGM I had, and I have 4 times the solar power (50W to 200W). The lithium battery is in a heated space in the cabin, and the BMV monitor is on the galley wall next to the system monitor.

It is interesting to watch the behavior of the solar charger while driving. I left the power on just so I'd get a little drain on the battery. If the Zamp solar charger detects the battery is charged, it goes into float mode with no current at all. As the battery slowly discharges, the Zamp will occasionally turn on for a few minutes to pump out 6 Amps to top it off. Then back into float mode.

[lapowers57]

What was the battery stand made from? How was it secured to the trailer, screwed to the floor?

[SilverHouseDreams]

Originally Posted by lapowers57

What was the battery stand made from? How was it secured to the trailer, screwed to the floor?

I used a marine battery tray that I screwed to the floor. It has a strap that locks battery into place. There is and endless assortment of battery trays on Amazon or elsewhere.