LiFePO4 Batteries?-gctid822438

[Fishtank]

What do you all think of these LiFePO4 batteries? They are unbelievably high performance - much faster charging and can be discharged much more than AGM or lead acid, can be used with existing battery chargers, and WAY lighter. They are also supposed to be safe relative to the typical Lithium Ion batteries. Yes, it's $900 but will outlast the life of a boat. https://battlebornbatteries.com/shop...ttery/#reviews

[Guest]

These seem to good to be true. Thanks for sharing the idea, following the thread to see if anyone has experience with these.

[SomeSailor]

They're the real deal, but that are sensitive the way they're charged and protected from excessive discharge. The price is really coming down as well.

[Norton_Rider]

This is the safest of the hi-tech battery chemistries and shows a lot of promise for boats. There are a few suppliers that claim that they can be charged with conventional chargers and alternators, but that's only true if you use a Battery Management System (BMS). Some have a built-in BMS and others use an external one. As SomeSailor said, they are very sensitive to charging rates/voltages and over discharge. Having said that, they can be discharged to almost zero capacity. This means that you can have a smaller capacity bank do the same job as a much larger lead acid bank. The other advantage is that they are extremely light, a plus on planing-hull boats with large house or starting banks.

[TenMile]

Makes both your boat and your wallet lighter! Sounds like a great technology but the price needs to come down on all the system components I'd think before they see adoption.

[Solandri]

Jump down to the section on lithium iron phosphate.

http://batteryuniversity.com/learn/a...of_lithium_ion

Looks like the drawbacks are

[ul]

[li]Very sensitive to moisture (can kill the cycle life to about 50 cycles).[/li]

[li]Faster self-discharge, so make sure you recharge the day before, and the individual cells (4 in series needed for 12.8 V) may need occasional maintenance if one becomes more discharged than the others.[/li]

[li]Maintenance charge of 14.4 V for an extended time (like when driving your boat) can stress the battery.[/li]

[li]Less power in cold weather.[/li]

[/ul]

[JThiessen]

900 bucks - as a replacement for a 100 dollar battery?

LiPo's have the advantage of weight and the ability to dump massive amounts of current in a short period of time (this also gives them the ability to charge fast also).

But as stated earlier, its really your battery management system that really counts. Never, ever go cheap here.

I've had LiPo's explode on me, and its quite a show. Only thing you can do to stop the reaction is to dump them in salt water......nothing I'd want in my boat. But they are awesome for RC's and power tools.

[nile]

Interesting site dealing with LiFePO4 batteries. They seem pretty safe until you intentionally short them.

http://www.diyelectriccar.com/forums...iii-82896.html

Could save 400 Lbs on a cruising boat.

[Norton_Rider]

Inadvertent short circuit can also happen with lead acid batteries, with bad consequences. If it were not for the huge initial cost, I would definitely switch to LiFePO4batteries. On my boat I would be able to reduce the battery weight (starting and house) by approximately 500 lb.

[TenMile]

Here is a good YouTube video that compares the cost, pros and cons of various battery types:

[Aircraftbuilder]

From the perspective of an RC aircraft hobbyist........ There is no way in God's green earth that I would put a LiPO (lithium polymer) battery in my boat. As noted in an earlier post, if these things decide to go "off", there is next to no way to stop it. They burn darn near like thermite . . HOT, fast and forever, plus they emit quite a bit of noxious gas/smoke. You may have seen in the news where there were some issues with LiPOs in the 787 Dreamliner that decided to burn up. In the RC hobby, LiPOs are stored and charged in special bags and usually in 0.50 cal ammo cans and charged out doors. There are some examples of some folks burning down their houses while charging indoors. LiPos can be funny things in that some can take some abuse and not have a problem, some will go off after some abuse and then there are those that will just decide that now is the time to self destruct!

On the other hand, LiFe batteries are much safer and these are what I use in my aircraft. But there are some caveats with these batteries. They have a very flat discharge profile until they reach a certain voltage, then they drop off a cliff. If you discharge LiFe batteries to minimal voltage, the battery is basically history as they don't recover from being discharged.

Again, this has been from my research, learning's and experiences in the RC aircraft side of these batteries. Good luck and be careful.

[Norton_Rider]

"Aircraftbuilder" post=822818 wrote:
From the perspective of an RC aircraft hobbyist........ There is no way in God's green earth that I would put a LiPO (lithium polymer) battery in my boat. As noted in an earlier post, if these things decide to go "off", there is next to no way to stop it. They burn darn near like thermite . . HOT, fast and forever, plus they emit quite a bit of noxious gas/smoke. You may have seen in the news where there were some issues with LiPOs in the 787 Dreamliner that decided to burn up. In the RC hobby, LiPOs are stored and charged in special bags and usually in 0.50 cal ammo cans and charged out doors. There are some examples of some folks burning down their houses while charging indoors. LiPos can be funny things in that some can take some abuse and not have a problem, some will go off after some abuse and then there are those that will just decide that now is the time to self destruct!

On the other hand, LiFe batteries are much safer and these are what I use in my aircraft. But there are some caveats with these batteries. They have a very flat discharge profile until they reach a certain voltage, then they drop off a cliff. If you discharge LiFe batteries to minimal voltage, the battery is basically history as they don't recover from being discharged.

Again, this has been from my research, learning's and experiences in the RC aircraft side of these batteries. Good luck and be careful.

LiFe and LiFePO4 are exatly the same thing. People just leave off the PO4 for short. This is definitely not the same chemistry as the 787 batteries. The 787, as well as many consumer devices use LiCoO2 batteries.

[SomeSailor]

"Aircraftbuilder" post=822818 wrote:
From the perspective of an RC aircraft hobbyist........ There is no way in God's green earth that I would put a LiPO (lithium polymer) battery in my boat.

LiPO and LiFe (or LiFePO4) and Lithium Ion (LiCoO2) are entirely different approaches. Lithium Ion and Lithium Polymer are different as well.

Boeing 787 uses lithium cobalt oxide (LiCoO2) which are indeed Lithium Ion batteries, and inherently more sensitive from a maintenance point of view. They can certainly charge fast and hold crazy energy. Not something I'd want on my boat. LifePO4 batteries are getting pretty attractive though.