Hello all ...
I've been pondering my options with respect to replacing the 2 Lifeline GPL-4DA batteries I've got in my 40' 08 Nimbus and I'm looking for any comments on my thought process as well as see if there's anyone with first hand experience with Firefly Oasis AGM batteries. I've seen a couple of references to these batteries on this forum but no first hand accounts.
If money was no option I'd move to Lifepo4, add some solar and upgrade my Xantrex to something appropriate to support it all. ... but .... I'm still waiting for my lottery numbers to hit :(
So, that's left me with throwing the net far and wide. I could just replace the Lifeline batteries but I don't like the fact that traditional lead acid batteries don't really provide more than 50% of the available rated juice without potential damage. And I don't know about you but the likelihood I'll never run them past 50% or deplete them entirely isn't good ... not that that's ever happened to me :facepalm: .
I've considered building my own Lifepo4 battery bricks out of components, adding protection ckts etc. but I'm left with questions about my current inverter/charger (Xantrex RS2000) being a good choice for charging/maintaining it over the long haul. Additionally, any cost advantage in building my own battery would rely on purchasing used or 'new old stock' online via ebay, or heaven forbid allibaba, which comes at (IMHO) significant risk and unknowns.
Which brings me to Firefly (https://www.bruceschwab.com/advanced-energy-storage-systems/firefly-energys-oasis-group-31/) AGM Carbon Foam batteries. When I stumbled across these I was surprised at the claims which are purportedly based their use of carbon foam and some other magic. The cost is not too bad considering the specifications... they even perform better in cold weather than lithium. If I understand the performance characteristics I think I can replace the 2 Lifeline batteries (210AH ea.) with 3 of the 110AH Fireflys and end up with more usable power when factoring the 50% usage limit imposed by traditional lead acid.
My pea brain math follows....
Firefly Oasis3ea 110AH in parallel = 330AH available per manuf. specs. If we assume 80-90% is available (per Firefly Oasis) for actual use then we get 264-297AH of 12V goodness.
Lifeline GPL-4DA2ea 210AH in parallel = 420AH available per manuf. specs. If we assume 50% limit else risk long term damage we get 210AH of I'm disappointed.
- The Firefly Oasis can be had for $512 (x3=$1536) which works out to $5.82/AH ($1536/264AH) of usable power and would weigh in at 225 pounds.
- Price on Lifeline batteries have come down over the last year as near as I can tell. An online search found these available as low as $579 (x2=$1158) which works out to $5.51/AH ($1158/210AH) of usable power and weigh in at 248 pounds.
Given the touted performance characteristics and assuming I'm not comparing apples to oranges, I'm ok with spending the additional few hundred dollars to move away from traditional AGM batteries with their 50% discharge limit .... but I feel like I'm missing something.
So ... what am I missing? Other options / thoughts ... first hand experiences?
Thanks for your time...
dan
This is first I've heard of these batteries, which surprises me if they really are as superior as is claimed. I may be overly skeptical, but I tend to steer away from things that seem "too good to be true"--and these batteries appear to be in that category.
If you do go with them then please keep careful records and frequently report back to us over the next several years. It would be great to learn that they really are superior in design and performance!
Firefly was a spinoff from Caterpillar Corp.
Firefly International Energy - History Of Innovation (http://fireflyenergy.com/about-us/history-of-innovation/)
I have no idea (plus or minus) on how it has worked.
You might try (4) Lifeline 6v (or other brand) L16 batteries in the same foot print.
David ... I'm with you on the skepticism and why I'm reaching out for some first hand info.
Brett, thanks for the link ... I hadn't seen this and it provides a bit more specific information.
I'm going to spend some time trolling other RV owner sites to see if there's more out there. What I've come across so far is that everyone is focused on Lifepo4 for upgrades ... I'm just looking for something better that's not so expensive.
Dan
Dan, how much space do you have for batteries? Vertical height? There are lots of battery choices.
This should keep you busy for a while:
Lead Carbon Batteries ??? help advice??? - Cruisers & Sailing Forums (http://www.cruisersforum.com/forums/f14/lead-carbon-batteries-help-advice-210252.html)
Float voltage for Firefly batteries - Cruisers & Sailing Forums (http://www.cruisersforum.com/forums/f14/float-voltage-for-firefly-batteries-205347.html)
Firefly Oasis Carbon Foam AGM Batteries - Cruisers & Sailing Forums (http://www.cruisersforum.com/forums/f14/firefly-oasis-carbon-foam-agm-batteries-173008.html)
Any two years reviews for Firefly batteries? - Cruisers & Sailing Forums (http://www.cruisersforum.com/forums/f14/any-two-years-reviews-for-firefly-batteries-194174.html)
Roger, I've got some room to play with ... my batteries share the compartment with the fresh water tank. Without measuring I can tell you that I could probably add a 3rd Lifeline battery and stack 3 more on top of those.
If I was to do that I'd then be worried about all the battery weight (750lbs?) plus 100-Gal (800lbs) of water all located in a relatively small area.
But ... I could go with 2 or 3 beefy batteries that are tall ... are there some in particular you're thinking of?
dan
Indeed ... starting now..
dan
Dan, you might be able to get four Fullriver DC400-6 L16 sized batteries in where the two 4Ds are now.
Fullriver Battery DC400-6 Product Information (http://www.fullriverbattery.com/product/batteries/DC400-6)
830 amp hrs total for the four. 123 lb each. 7 yr warranty.
I used Fullriver because of the warranty and performance characteristics. And because there is a stocking wholesale distributor not too far away who gave me a good price and no shipping.
Lots of other L16 choices if that is how you want to go. After two years on mine they are flawless.
The Fullriver DC335-6 have the same footprint but are shorter. 335 amp hrs for a pair.
The short answer is that they use carbon foam which is carbon "sponge" like material that is almost pure carbon which, being a 'foam' has lots of little pockets in it and as it's stiff makes an excellent separator and insulator between the plates in the battery. It is still a conventional lead acid chemistry just a better way of constructing it. The original problem it was designed to overcome was mechanical damage to the batteries in high vibration environments found in construction/mining equipment. Nothing magic here just a more efficient method of building a conventional battery.
If you want to see an entertaining way of making carbon foam see this guys web channel. His language can be a little salty at times so lock up the wife and kiddies first.
https://www.youtube.com/watch?v=Wex_yKfrTo4
Keith
Dan,
Thanks for bring up the FF battery, had never heard of it. My coach has two 8G8D house batteries. I was trying to figure out how the FF G31 would fit and work in my coach. Seems like I would need 3 and there is not enough room for 3. The FF L15 4v (would need 3 for 12v) would fit though with them mounted on the side rather than upright, resulting in a 450 AH battery with a $4.95 cost per AH. An added bonus is that the terminals would be easy to access and 94 lbs is easier to handle than a 157 lb 8G8D. I don't need house batteries right now, but will keep this in mind.
AvE is one of my guilty pleasures. Highly recommended that you subscribe to his youtube channel.
see ya
ken