23 replies to this topic

[PaulT]

Several observations from someone interested for my camper, and for my ham radio hobby.

1. These are Lithium Iron Nanophosphate which is likely the A123 technology developed for electrical vehicles and probably good

2. Have heard of demos where a nail was shot into a battery pack under load and nothing exciting happened other than losing that cell.

3. For long term life and maximum performance, chargers may need to be able to equalize individual cells. While you may be able to get to 80% charge in 15 minutes (given sufficient solar PV panels, chortle The cells need to be managed differently for the remaining 20%.  (http://www.buddipole...tablepower.html)

4. I would use marine fuses that attach directly to the battery post/connectors as these batteries can dump incredible amounts of amps into a short circuit. (See http://neverded.com/maxx/  or http://antigravityba...com/microstart/ )

[Ethergore]

Several observations from someone interested for my camper, and for my ham radio hobby.
1. These are Lithium Iron Nanophosphate which is likely the A123 technology developed for electrical vehicles and probably good
2. Have heard of demos where a nail was shot into a battery pack under load and nothing exciting happened other than losing that cell.
3. For long term life and maximum performance, chargers may need to be able to equalize individual cells. While you may be able to get to 80% charge in 15 minutes (given sufficient solar PV panels, chortle The cells need to be managed differently for the remaining 20%.  (http://www.buddipole...tablepower.html)
4. I would use marine fuses that attach directly to the battery post/connectors as these batteries can dump incredible amounts of amps into a short circuit. (See http://neverded.com/maxx/  or http://antigravityba...com/microstart/ )

Thanks for the info. I have noticed it seems most of these batteries are made of the tiny a123 cells. Kind of like playing with Legos.

Ideally, I'd like to build our buy a battery box that will fit into my stock battery compartment and then configure the most a123 cells possible into a large 12.8 volt cell. Seems like this would be the cheapest and most efficient setup. I just can't seem to find a nice how-to anywhere.

[craig333]

As long as these aren't prone to catching fire I'm in. Just as soon as I win the lottery.

[PaulT]

Electrical shorts are the greatest fire danger with these batteries. In addition to the fuses, I would insist on electrically insulating covers over anything that is attached to the battery terminals on the uphill side of the fuses.  Dropping a wrench or screwdriver across the hot terminal and a return path would likely create a very bright flash with tons of UV energy and the vaporization of the tool and the elimination of any remaining hair on one's head.  Not to mention the very bright spot in the center of vision for a long time.

 

I do think we will see great strides over the next few years in availability of suitable Lithium based battery packs that would be of use to us intrepid boon docking refrigerator users.  My AGM camper batteries are new this summer. Perhaps, better choices will be available at more reasonable costs when they need replacing. However, I know that all my chargers will also need to be replaced.

 

A not too early adopter.

Paul

[mib]

Oops. Forgot to paste the link.
http://www.batterysp...passed-dgr.aspx

4 in series will give you 100Ah at 12.8V.

So still a lot of usable Ah (maybe comparable to a 200Ah lead battery), but you're at 700$ then. So maybe double the price as AGM.

A lot of the explosion issues are less of a concern in LiFePo than in LiPo.

 

I have a bluetop Optima with 55Ah in the camper we bought.

As an upgrade option, I have LiFePo in mind. My battery management system will be this one from kickstarter: https://www.kickstar...development-boa

I hope to get it next month, and then play around with some 2.5Ah 18650 LiPo first - if it turns out comfortable to use, I think about upgrading the battery. But this thing is definitely no plug-n-play solution yet.

 

The solar panel is the flexible Renogy 100W that will go on a wind deflector above the cab (lots of projects to work on ... )

 

best,

Mike

Edited by mib, 11 September 2014 - 02:33 AM.

[Ethergore]

Wow. I can't believe how little I know about batteries now. I had no idea the amp hours don't increase when the voltage does. That really does increase the cost. Makes it a much more difficult decision.

I think I need to go back and edit some posts about my 2 6-volt golf cart batteries making 400 amp hours.

Any posts you see from me in the future will be from a much more humble person. :-/

[MarkBC]

In series you add the voltages but not the current.

[deethe]

i had initially planned to install a lithium capable mppt solar controller but the highest wattage rating i could find was a Votronic at 350w, so i eventually settled on a Midnite solar KID for the 390w array.  (with a firmware update this controller may be able to do lithiums, idk?)

[enelson]

Depending on how the 390W array is mounted you may never get the full current out.  The Votronic controller should be sufficient.

[craig333]

One of these days when the prices come down to something I can stomach. I'm glad someone is leading the charge though