Tuesday, September 18, 2018

Re: [Electric Boats] Battery replacement

 

It is interesting to read this post on battery replacement.
I read the whole thing and there has been no mention of NIMH batteries.
Many Hybrids use NIMH. Toyota stayed with it over Lithium, until maybe recently(I haven't looked at a new prius in a while.)
NIMH is very fault tolerant and not much of a fire risk.
It can put out alot of amps if shorted too, so don't drop a wrench across the terminals.
Our family has 3 ford escape hybrids ranging from 2005 to 2008. None of these vehicles have ever had a battery issue. That is 13 years for the 2005.
I have taken a pack apart from the wreckers to see how well they are and they are close to new in capacity.
The drawback is they are only 5.5AH cells due to the use of copywrite law to limit anyone to make a larger NIMH. Check on the internet Patent encumbrance of large automotive NiMH batteries



I have used the 5.5AH cells(from a ford escape hybrid) in an electric bike, at 36 volts in parallel to get an 11AH pack at 36 Volts.
Unfortunately on a bike and with the fords cell format, I was close to the same weight as lead acid.
If I had a large sailboat, I would probably try to build a NIMH pack to see how it performs.
NIMH does lose capacity while sitting too, but if it is on a boat with solar, it would stay charged.

Just food for though, as there are no large capacity cells available due to the pattents.


On Monday, September 17, 2018, 5:03:57 p.m. PDT, Rob rob@sail4life.net [electricboats] <electricboats@yahoogroups.com> wrote:


 

The only batteries I've *ever* seen that has lasted more than  decade is a group of Wet Cell Nickel-Cadmium batteries I saved rom the landfill when we were replacing railroad crossings (they were used to power the lights and arm swing).  Energy density was pretty low IIRC, but they were robust as (fill in blank). At least one set was manufactured in the 1970's and we pulled them in 1990. I ran all sorts of charge discharge tests and finally decided they were ok to put in the boat. sold the boat 3 years later, never having touched them again. 


Note: WET cell Ni-Cd are completely different animals than dry cell ni-cd like you get in el cheapo tools. No memory, full discharge tolerant, over-voltage charging tolerant, etc. IIRC, they were 2v cell, about 14" tall by 3" x 6".

-Rob


On Sep 17, 2018, at 4:31 PM, 'james@deny.org' james@deny.org [electricboats] <electricboats@yahoogroups.com> wrote:

...
Now these new Lead battery chemistries may fix the long standing reliability issues with Lead batteries, who knows they may last decades. But quite frankly we will have to wait ten years to see, if I start seeing live aboard cruisers regularly getting 10 years from there Lead house banks then I may start to trust Lead batteries again, but I already know for a fact, that LiFePo packs do regularly last 10 year, and are still going strong. Even then I will still harbor some pretty strong fears related to Lead reliability. I have to many years dealing with them professionally inside large data centers, and I was an very early EV adopter from way way back. Both in data centers and in EV's, lithium transformed both UPS's and EV's from nearly useless toys to everyday useful trustworthy reliable devices. 

Just my opinion, based on my experience, yours may very. 

....

__._,_.___
Posted by: Mark F <mark.internet@yahoo.ca>
Reply via web post • Reply to sender • Reply to group • Start a New Topic • Messages in this topic (66)
Check out the automatic photo album with 2 photo(s) from this topic.
OLD batteries.jpg PACK WITH BMS.JPG
Have you tried the highest rated email app?
With 4.5 stars in iTunes, the Yahoo Mail app is the highest rated email app on the market. What are you waiting for? Now you can access all your inboxes (Gmail, Outlook, AOL and more) in one place. Never delete an email again with 1000GB of free cloud storage.

SPONSORED LINKS
.

__,_._,___
Posted by at

No comments:

Post a Comment

Subscribe to: Post Comments (Atom)