Renogy on sale

[markopolo]

Originally Posted by booster

..................

What they seem to say differently:

...................High charge and discharge rates shorten LFP life per the article and both are best at about .3C which is about the same as AGM..............

I need to find out more about that .3C recommendation. For example: What would the lifetime capacity gain be over using a much smaller battery at 1C or 3C discharge rates periodically and also compare that to the cost of 3 to 10 times more battery battery needed to stay within that .3C recommendation.

[booster]

Originally Posted by markopolo

I need to find out more about that .3C recommendation. For example: What would the lifetime capacity gain be over using a much smaller battery at 1C or 3C discharge rates periodically and also compare that to the cost of 3 to 10 times more battery battery needed to stay within that .3C recommendation.

I think that would be good to know, if that information is available.



We hear all the time that this or that will shorten life or that and this will lengthen it, but rarely with any real data. I think the author did make some comment about continual high rates being the issue and that occasional would not be a big deal, but I may be misinterpreting it.


The momentum toward lithium seemed to be gaining strength as time went on and more installs were done, but now we seem to be seeing some backlash that is contradicting some of the main advantages that have been touted for lithium. I don't know if it is just skepticism or whether the realities of the quite difficult conditions that RV use puts on batteries are starting to be more fully understood in relation to lithium.


I think there is still a long ways to go before we really know how it will all shake out over time.

[markopolo]

For those that want LFP, all of the issues are manageable with the right equipment. It starts with awareness of the issues and knowing which apply to your usage pattern then how to take care of those issues.

More info here on LFP memory effect: LFP memory effects thread - Cruisers & Sailing Forums

[RossWilliams]

For those that want LFP, all of the issues are manageable with the right equipment. It starts with awareness of the issues and knowing which apply to your usage pattern then how to take care of those issues.

I think that is right. But I suspect there are a lot of rv owners who just want to go camping and not have the lights go out. It is pretty difficult for an RV manufacturer to anticipate everyone's usage pattern. The memory effect means that the simple idea of making light use of your batteries doesn't really work for lithium batteries. It also means your solar panel and charger may damage the batteries if relied on to maintain the batteries' charge.

Of course, other battery types have limitations as well. But most of those issues are solved by sizing the batteries appropriately for your use and/or using them appropriately for their size.

There are not a lot of Rv owners who have been using lithium batteries for 5 years yet. But there seem to be quite a few who have had problems. Mostly that gets blamed on poor design, lousy charging and bad batteries or abuse. But it may be more that lithiums have some inherent problems in common RV environments.

[booster]

Originally Posted by markopolo

For those that want LFP, all of the issues are manageable with the right equipment. It starts with awareness of the issues and knowing which apply to your usage pattern then how to take care of those issues.

More info here on LFP memory effect: LFP memory effects thread - Cruisers & Sailing Forums

Of all the possible issue with lithium that we know of or heard that may be there, the memory effect might be the most important if it is truly as stated in the article.


The article plainly says that the effect can be counteracted by full charging and discharging regularly, but that goes contrary to the information we have seen on the life of LFP shortening appreciably if fully charged all the time or taken to deeper discharges. Mid range, short charging, without damage is the big deal with LFP over AGM, so to lose that capability would not be good.

[GeorgeRa]

I dived to some of the links from this thread, a lot of experience on the cruising forum. Voltage bump, memory loss, recoverable or not, wow. It seems as this technology edge is still technology edge. This post is explicit. LFP memory effects thread - Page 12 - Cruisers & Sailing Forums

[rowiebowie]

Renogy is running a 15% Sale next week (Nov. 9-14, 2020).

According to the e-mail I received today, it is "SITEWIDE, NO EXCLUSIONS".

[bumpersignal]

are these recommended to install in the coach? I really want a drop in replacement where the old AGM's go (outside and under hood).

[rowiebowie]

Originally Posted by bumpersignal

are these recommended to install in the coach? I really want a drop in replacement where the old AGM's go (outside and under hood).

"Drop-in replacement" is a sales gimmick and even Battleborn acknowledges this when you speak to one of their representatives. Do lithium batteries work with certain chargers? Yes, but not well and do you want to risk degrading your sizeable investment and shorten their life span? Not to mention the possibility of burning out your engine alternator from the higher charge rates lithiums can absorb.

You need charging components with lithium-compatible charge profiles. That means charger, solar controller, and a DC to DC charger between your lithium coach batteries and your lead-acid coach batteries to protect your alternator.
You also need a battery monitor to get a true state-of-charge reading.

If any of your exhisting components already have lithium charge profiles, you can keep them. But that will be rare to find unless you recently changed those components and were thinking ahead.

To my knowledge, there is no under hood lithium battery suitable for use for the engine.

[bumpersignal]

I think I’d be ok with all those needing to be upgraded. However placement of the lithium is my biggest issue. I’d need them to still be either under hood or under chassis where the original agm are. I don’t like the idea batteries being inside

[rowiebowie]

Inside is the ideal place for lithium batteries. They are safe, no off-gassing, can be mounted at any angle, and don't like to be below freezing anyway. Mine took up some storage space (always a premium in a class b), but it was no net loss after I repurposed the outside area for storage of my leveling boards and jumper cables.

However, if you don't want to relocate, I understand. And if you live and travel in mild climates, it won't be a problem.