Deep Cell Battery Replacement

[thomasgibbens]

After 7 years of use, I need to replace our deep cell house batteries. The are presently Discover-Energy model EVGV6A-B 6 volt batteries. I am looking for recommendations on the manufacturer. I am leaning towards Interstate Batteries but am open to suggestions. 
 

Tom Gibbens

’15 Dynasty 45D

[Walker]

I installed trojan golf cart batteries.  So far I have been happy and they were slightly cheaper than interstates.

[Bob Blackmon]

I don't believe there is a better AGM battery made than Discover. They are worth the price.

[Jdw12345]

I recently purchased a used 05 Dynasty and the Full River 6v DC250 house batteries are 7 years old, I’ve been considering replacing them with the same or Lifeline.  I have no opinion just trying to learn more…..

[Ivylog]

The price of Lithium cells (build your own batteries) has come way way down in the last couple months…BUT the current backlog of container ships may require waiting on them for months.

I recently ordered 8 280AH cells … enough cells to make 2 batteries for a total of 560AH. Including a basic BMS and probably 10 hours of my time the cost will be $1/AH, about the price of lead acid golf cart batteries. The Lithiums should last 5X and you can use 90+% of their AHs instead if 50%. Battle Born wants $7+/AH.

It’s really not that hard to build…plenty of videos on how. 6 months ago I thought I’d done well building 600AH of batteries for $2/AH…$1200 instead of Bend over Born’s $4800 price.

Yes, you cannot charge Lithiums when frozen…can still discharge them. Charging takes a slightly higher voltage but a AGM setting will do the job.

[RoadTripper2084]

18 hours ago, Ivylog said:

The price of Lithium cells (build your own batteries) has come way way down in the last couple months…BUT the current backlog of container ships may require waiting on them for months.

I recently ordered 8 280AH cells … enough cells to make 2 batteries for a total of 560AH. Including a basic BMS and probably 10 hours of my time the cost will be $1/AH, about the price of lead acid golf cart batteries. The Lithiums should last 5X and you can use 90+% of their AHs instead if 50%. Battle Born wants $7+/AH.

It’s really not that hard to build…plenty of videos on how. 6 months ago I thought I’d done well building 600AH of batteries for $2/AH…$1200 instead of Bend over Born’s $4800 price.

Yes, you cannot charge Lithiums when frozen…can still discharge them. Charging takes a slightly higher voltage but a AGM setting will do the job.

I'm researching right now and would like to upgrade to LifePo4 for the house batteries, assemble my own as you have done.

What I'm struggling with is figuring out the "minimal" required other components in my rig that I'd have to replace to do so (doesn't make much sense to go lithium if I have to spend 2x for new converters, smart battery monitors, etc. as well).

Thus far I *think* the path of least cost may be to use a DC-DC charger between the lead acid chassis batteries and the LiFePo4 house batteries, and simply charge the house batteries whenever the chassis batteries are being charged (detect higher chassis battery voltage). I'm not sure if I also need to disconnect the house batteries from the existing coach charging circuits or if that can be left in place, since the voltage levels are all low enough that they can't overcharge the lithiums in any case?

How have you got your lithium house batteries setup in the coach? 

[Ivylog]

This summer I ran a combination of AGM & Lithiums house batteries… built the Lithiums sooner than I really needed as the AGMs still have several years of life left in them. With the recent drop in cell prices I should have waited, never thing you could build a 12V Lithium for $1/AH.

You can charge a lithium to 90% of capacity with the chargers that are in our motorhomes. I have my doubts that you need a DC to DC limiting device because the wire from your alternator isn’t capable of passing more amps than what the alternator can take.

I already run the generator in the morning before leaving after dry camping so that the alternator doesn’t have to charge the batteries as much. I’ve already installed a remote sensing temperature probe on my alternator to get a baseline of what is normal for it so when I start charging Lithiums with it, I’ll have a better idea if I really have a problem.