Having learned so much from members here since my initial posts in early 2018, I've been grateful that the learning curve has been relatively steady, and informative. I've truly appreciated the guidance...Today, considering replacing my standard deep cells - each 115 min @75 amps, 220 Ah at 20 hr - with 100 Ah Lithium batteries is on my mind. I'm thinking 3 would do the trick, but have room for 4...My rig is a 2017 Newmar Ventana LE 3436. I've got 480 W Zamp solar producing 26.1 peak Amps, a 30A Controller, plus a external, portable solar panel at 120 W.The Li choice seems clear to me, as a distinct cost advantage over time, and fits well with my goal to enjoy more dry camping... The question is, should I consider adding another 160-320 W solar? Of course, would need to obtain new controller, thinking MPPT would be best - note that I ask because of my tendency to plan for worst case scenarios, and feel a certain peace of mind knowing I'd have sufficient power to last a week without sunshine... shade is nice, but that doesn't help the solar much...

I think you have 4x 6V at 220Ah for 440Ah. 50% discharge is 220Ah. 3X 100Ah li would be equivalent at 80% discharge for 240Ah. Esentially equilavent. I would first use the new batteries to give a better input on your usage etc. Then evaluate adding more solar or a 4th battery.Li batteries need a different charging system. Have you considered that? Also will your solar controller correctly charge Li's?

If your current batteries are working well why upgrade now? A potential 220 AHs available for use is a bunch of power.

Have the current batteries proven inadequate and yet spend a lot of time in absorption phase of charging at limited amps?

CA Traveler wrote:I think you have 4x 6V at 220Ah for 440Ah. 50% discharge is 220Ah. 3X 100Ah li would be equivalent at 80% discharge for 240Ah. Esentially equilavent. I would first use the new batteries to give a better input on your usage etc. Then evaluate adding more solar or a 4th battery.Li batteries need a different charging system. Have you considered that? Also will your solar controller correctly charge Li's?Yes, a new controller would be necessary if I add more solar... anything greater than 3.9Ah would call for a new controller, and yes, it would have to be capable of charging... makes sense to start with the Li, then evaluate to determine if a 4th is necessary, and if solar would enhance to system...

Li's require different and unique charging and charger. Does your mfg 120VAC charger whatever it is have that capability? Does your solar controller also have that capability? Not a question of additional solar or batteries.

Lithium Vs. More Solar | Good Sam Community

69 Replies

CA_Traveler
Explorer III
Aug 16, 2020
Read up on Li charging. You can charge with a flooded charger and you can also damage Li batteries with one. Basically set the voltage for Li and when done charging remove the charger. Well OK if you want to do that every time. Automatic equizalation is also a no no.

Here's one source: https://enerdrive.com.au/2017/11/29/can-charge-lithium-battery-lead-acid-charger/
Itinerant1
Explorer
Aug 16, 2020
CA Traveler wrote:
Li's require different and unique charging and charger. Does your mfg 120VAC charger whatever it is have that capability? Does your solar controller also have that capability? Not a question of additional solar or batteries.

What is so unique or different for charging?

Yes having a programmable system would be best but certainly not needed.
pianotuna
Nomad III
Aug 16, 2020
obinwan,

If you go with SiO2 chemistry, there doesn't need to be any change to the charging. You may save about 1/2 the price, too.

I prefer large capacity banks, and since I'm no longer full time my weekender needs are met by the existing solar charging system.
time2roll
Nomad
Aug 16, 2020
Lithium charging is not really that different or complex. Although a controller with adjustable set points could be needed.
CA_Traveler
Explorer III
Aug 16, 2020
Li's require different and unique charging and charger. Does your mfg 120VAC charger whatever it is have that capability? Does your solar controller also have that capability? Not a question of additional solar or batteries.
obiwancanoli
Explorer
Aug 16, 2020
CA Traveler wrote:
I think you have 4x 6V at 220Ah for 440Ah. 50% discharge is 220Ah. 3X 100Ah li would be equivalent at 80% discharge for 240Ah. Esentially equilavent.

I would first use the new batteries to give a better input on your usage etc. Then evaluate adding more solar or a 4th battery.

Li batteries need a different charging system. Have you considered that? Also will your solar controller correctly charge Li's?

Yes, a new controller would be necessary if I add more solar... anything greater than 3.9Ah would call for a new controller, and yes, it would have to be capable of charging... makes sense to start with the Li, then evaluate to determine if a 4th is necessary, and if solar would enhance to system...
time2roll
Nomad
Aug 16, 2020
Have the current batteries proven inadequate and yet spend a lot of time in absorption phase of charging at limited amps?
Lwiddis
Explorer II
Aug 16, 2020
If your current batteries are working well why upgrade now? A potential 220 AHs available for use is a bunch of power.
CA_Traveler
Explorer III
Aug 16, 2020
I think you have 4x 6V at 220Ah for 440Ah. 50% discharge is 220Ah. 3X 100Ah li would be equivalent at 80% discharge for 240Ah. Esentially equilavent.

I would first use the new batteries to give a better input on your usage etc. Then evaluate adding more solar or a 4th battery.

Li batteries need a different charging system. Have you considered that? Also will your solar controller correctly charge Li's?

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Lithium Vs. More Solar

69 Replies

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