Sanity Check My Electrical Upgrade Plans Please?

[Vic]

After 4+ years of use (including one boneheaded resulting in low 9.0 volts and a few exposed plates last winter and a refill of distilled water), my 2 trusty 6v Golf Cart batteries are near the end I believe. They don't owe me anything and I'm not complaining, but I am going to take this opportunity to upgrade. And do it now so I'm ready for warm weather. Rather then a futile effort to try to squeeze one more season out of them and be doing this the night before a trip. Anyway....

After some time on the phone with the great folks from Battle Born Batteries and reading a ton of webpages, I have my plan in order. They were absolutely stellar in assisting me and my limited electrical knowledge. As I finalize my order with them, I want to put my thoughts in order and appreciate any input. I never thought I'd spend $1000 on a battery, but buy once, cry once, right?

My rig - 2015 Hallmark Everest. 3+ season camper but have been known to camp in single digits.

Currently
2 GC2; 6v 210 ah batteries
200w of Solar on the roof
Zamp ZS-30A Solar Controller
Progressive Dynamics PD4045KA converter

My Plan:
No changes to the solar panels or the Zamp
Swap out the converter section of the PD converter to a lithium compatible brain (seems easy enough?)
Add a Victron 712 with bluetooth and a display (also seems relatively easy...and cool data)
1 Battle Born 12v 100ah battery (heated, for those cold trips)

Despite my normal 'more is more' tendencies, I'm going to start with just a single 12v. I'd need major carpentry to fit two, and if it just isn't doing it I can add a second next year (but then likely need more solar). And truth be told when the 6v's are working well, I did have adequate power for my style of camping.

Any other components or pitfalls I'm not thinking of? I fully admit electrical is not my area of expertise, but I can follow basic instructions and this doesn't seem that challenging. I was a little concerned about the upgrade of the PD converter, but as I pulled the panel this afternoon it doesn't look that bad.

I've never gotten good charging off of the truck, and am hoping this change may help that issue as well. For reasons I don't understand, I frequently had the solar boiling off the batteries last summer. Probably due to my mistreatment of the batteries. One of my goals on this project is a low maintenance set up that is somewhat idiot proof.

I do have interior access to my battery box so in cold temps I can open a cabinet door and let them enjoy the heat. I also plan to insulate the front of the currently vented battery box.

It is always helpful to put my thoughts in order and appreciate any comments or suggestions.

Thanks!

-Vic

 

[Vic Harder]

Vic, that all looks good, although I am concerned about your statement: "I frequently had the solar boiling off the batteries last summer". That would indicate a setting that is not right. Did BBorn support give you settings for your ZAMP?

 

[lmwilco1]

I installed the Victron 712 in my camper and I find I never use the display, the phone display is much better. You can buy the Victron smart shunt instead and save a few dollars. I purchased a PD Lithium compatible charger and it is not very smart. It is a 14.6V power supply, there is no way to set the charge cutoff voltage so I am stuck with 14.6V. I would check the converter that you are looking to see what the lithium charge profile is like. For the truck charging you will probably need much larger power cables and maybe a DC to DC charger. I would do some searching about alternator charging of Lithium batteries.

If you are adventurous you could look into building your own battery from raw cells. It is not as simple as slipping a Battle Born battery into the camper but the cost and capacity are much better.

Good luck and looking forward to see how you proceed.

 

[Vic]

Vic, that all looks good, although I am concerned about your statement: "I frequently had the solar boiling off the batteries last summer". That would indicate a setting that is not right. Did BBorn support give you settings for your ZAMP?

Thanks Vic - we did discuss that and BBorn advised the AGM setting on the ZAMP matched perfectly.

On a nice sunny day last summer, I could see the ZAMP reading 14.6 volts and hear my old 6v's bubbling - in fact they would occasionally set off my propane monitor (I'd have to pull the fuse) I had suspected a bad cell in one of the 6v's would trigger that, but now I'm wondering?

I installed the Victron 712 in my camper and I find I never use the display, the phone display is much better. You can buy the Victron smart shunt instead and save a few dollars. I purchased a PD Lithium compatible charger and it is not very smart. It is a 14.6V power supply, there is no way to set the charge cutoff voltage so I am stuck with 14.6V. I would check the converter that you are looking to see what the lithium charge profile is like. For the truck charging you will probably need much larger power cables and maybe a DC to DC charger. I would do some searching about alternator charging of Lithium batteries.

If you are adventurous you could look into building your own battery from raw cells. It is not as simple as slipping a Battle Born battery into the camper but the cost and capacity are much better.

Good luck and looking forward to see how you proceed.

I suspect you are right and a future project will be the alternator charging; its through the small plug in the camper pigtail and I'm sure fairly light wire. I'd love to build my own but its a bit beyond my skill right now. Maybe my next upgrade?

To your comment on the constant 14.6...I was under the impression this was optimal to rely on the BMS. From the specs on the PD converter I've got planned:

The optional OUTPUT MODE SWITCH sets the converter output to either a constant 14.6VDC with the Charge Wizard® disabled (switch in ‘LI’ position) or a nominal 13.6VDC with full Charge Wizard® function (switch in ‘LA’ position). ‘LI’ mode is intended for use with lithium batteries with a BMS requiring a constant converter output. ‘LA’ mode is intended for use with lead/acid batteries where the Charge Wizard® will optimize battery charging.

I'm inferring from this the constant output is optimal? But again I'm new at this so appreciate an clarification.

-Vic

 

[Vic Harder]

14.6 seems like a lot. I use 14.2 on my BBorns. And a 13.3v float charge.

 

[rando]

I would second what Vic (H.) says, 14.6V is too high for the lithium batteries. Yes the built in BMS will protect them from real damage, but it should be thought of more as a backup system. A bulk charge around 14 - 14.2V is better, and then you don't want them to float. Certainly not a good idea to have them sitting at 14.6V for long periods of time.

Also, skip the heated batteries. If you can, insulate the outside of the battery compartment so it stays closer to the inside temp of the camper. You mentioned this was a 3 season camper, how often will you use it at an average temperature below 25F?

 

[PaulT]

You have two GC2 batteries now. Consider a BB GC2 100 aH battery. You should be able to add the second one later if desired without using carpentry skills.

Paul

 

[lmwilco1]

I agree that the PD Lithium charger is a waste of money. My solar has been keeping the battery charged. If I was at a location where power was available I might use it for a short time to top off the battery if needed but nothing beyond that.

 

[Vic]

Thanks all for the thoughts - more to chew on for my next steps. The puzzle is becoming clearer!

-Vic