Batteries: AGM vs LiFePO4 - Page 2

**Kidkraz** · 05-28-2018, 10:21 PM

Sara, just reading this and was wondering if you contacted the folks who made yer solar controller. Awhile back I was considering going to a higher rated solar panel and reached out to Samlex. They were really good and gave me some eduction on what I needed to look for when upgrading the panel. Just wanted to toss that out to ya.

**Bailey'sMom** · 05-28-2018, 11:14 PM

Quote:

Originally Posted by Kidkraz

Sara, just reading this and was wondering if you contacted the folks who made yer solar controller. Awhile back I was considering going to a higher rated solar panel and reached out to Samlex. They were really good and gave me some eduction on what I needed to look for when upgrading the panel. Just wanted to toss that out to ya.

No I haven’t. My tm is tucked away in the garage and I don’t plan to take it out til end of June when I will replace batteries. I did look in my manual to see which charge controller I have and I don’t think it’s a Samles. Don’t recall at the moment. But I believe it is a three stage??? Can’t look it up,right now.

**Bailey'sMom** · 05-28-2018, 11:35 PM

Quote:

Originally Posted by J_Norris

I'd love to see you try just so I can learn from your experience. I'm getting a LiFePO4 battery for my e-bike after lots of research into their safety and longevity (both much better than the LiIon batteries in phones).

I also still occasionally do backpacking and I think the tradeoff between cost and something being lightweight is personal and I really value quality lightweight gear of any kind.

In the interest of encouraging you, I found this that you may have already seen.

http://www.jenericramblings.com/2017...ng-to-lithium/

BTW, just because I want them to be a good idea doesn't mean they necessarily are

I'll be considering them when we replace our batteries. So please report back on how you decided and why.

That was an excellent article. Thanks for the link.

**ShrimpBurrito** · 05-29-2018, 10:17 AM

One manufacturer that has been installing lithium batteries in their RVs for years is Kimberly Karavan in Australia. If you just google their name and "lithium", you'll find lots of hits of people who use them, who have converted their RV to lithium (including several done several years ago), and also probably some sales pages from Kimberly itself. They are a specialized manufacturer making high end campers for off-road, off-grid use, where maximum extended dry camping time is a priority. That's in contrast to the mainstream US manufacturers, who are just interested in putting in the cheapest battery they can find, as most users plug in to shore power.

Dave

klpauba · 05-29-2018, 10:49 AM

I had also read that the discharge rate of (some?) Li RV batteries is limited making it necessary to limit the use of inverters with a capacity larger than some value (like 1KW or 1.5 KW). Other than the price, most of the features of these batteries can be hard to resist.

**rickst29** · 05-29-2018, 11:59 AM

On a 2619 like mine (with Batteries on the Hitch Tongue, behind the Propane Tanks) the installation would be inside - because, at roughly $1000 each, I would not want those batteries exposed to thieves. (They don't emit hydrogen gas, and are safe to use inside - without venting.)

Good Solar controllers are easily re-programmed to provide "correct" voltages to batteries which have built-in BMS. (In particular, the "Float Voltage" needs to be brought way down - about 13.2V.) But older TM power converters and cheap replacements (WFCO, Boondocker, Parallax) are not programmable, and the too-high "Float Voltage" presets (~13.7, maybe even 13.8V) will cook the LiFePO4 batteries in fairly short order. So the shopping list probably needs to include a new Converter, and not just new batteries.

It is sometimes said that you can discharge these batteries "all the way to zero, without damage", but I think that's not actually true. Going below 10% SOC on a regular basis does hurt them, so a Battery Monitor (programmed for LiFePO4 SOC characteristics) would be a good thing. Still, If you buy "200Ah" of 12v Lithium batteries, you can comfortably use up to 160Ah of that capacity. With SLA "safe" battery usage limited to about 50%, you'd need 320W of labeled capacity to match 200A of lithiums - and they'd weigh a lot more. And they'd all become worn out in 4-5 years, rather than 10-12.

There's are two place in my town which assembles and sells these batteries for RV and Marine use (12V, with BMS already built-in), along with the relevant add-ons and upgrades you probably need. Give 'em a look, and read their FAQ: https://battlebornbatteries.com/, is one good place (selling their own made-in-USA batteries), and https://theinverterstore.com/ is another. "The Inverter Store" is the retail web outlet for AIMS, which sells imports from China under their own brand.

**Bailey'sMom** · 05-29-2018, 01:01 PM

Quote:

Originally Posted by rickst29

.

There's a place in my town which assembles and sells these batteries for RV and Marine use (12V, with BMS already built-in), along with the relevant add-ons and upgrades you probably need. Give 'em a look, and read their FAQ: https://battlebornbatteries.com/

Yes I found their website yesterday. Lots of good info.

**rickst29** · 05-29-2018, 01:06 PM

Quote:

Originally Posted by klpauba

I had also read that the discharge rate of (some?) Li RV batteries is limited making it necessary to limit the use of inverters with a capacity larger than some value (like 1KW or 1.5 KW). Other than the price, most of the features of these batteries can be hard to resist.

LiFePO4 batteries (and battery packs) support huge discharge rates. BattleBorn allows 1C continuous output on their batteries - so a single 100AH battery can do up to 1280 Watts continuous (for somewhat less than an hour). My own new battery 150ah and also rated for 1C continuous discharge, can deliver up to 1920 watts continuously (but not for a full hour). That can pretty easily handle my new "1.5kW continuous" Inverter at maximum load. Although I don't plan to use it that way, I will be connecting the battery and Inverter using either #6 AWG or #4 AWG.

tentcamper · 05-29-2018, 08:29 PM

If you go Li battery. Make sure you plan on a new converter or charger. Li require very good and smart charging and battery control systems designed for Li. The life and capacity will not be there if you don't have the right charging system. Drop to low or overcharge and I believe the battery is tost.

**Bailey'sMom** · 05-29-2018, 10:32 PM

Quote:

Originally Posted by tentcamper

If you go Li battery. Make sure you plan on a new converter or charger. Li require very good and smart charging and battery control systems designed for Li. The life and capacity will not be there if you don't have the right charging system. Drop to low or overcharge and I believe the battery is tost.

Yes, I was looking at my blue binder and I have a Mark 1512 solar charge controller. It would appear that I would need to replace it if I change battery format.

Can someone please confirm whether or not I have to replace the charge controller if I decide to,switch to AGM batteries? I think that is probably a yes. It’s a definitely yes if I go to lithium batteries.

Next question would be which one to buy and how easy is it to install for a not real good electrical fraidy cat? I will have assistance from my sister who is much handier than me.

Thanks for all the input.