Search found 62 matches

by Rory166
Tue Sep 16, 2014 7:37 am
Forum: All things battery related
Topic: Lithium Battery Life
Replies: 1
Views: 5141

Lithium Battery Life

There are some interesting lectures on lithium batteries on Youtube. I watched one on methods of testing that do not require full lifetime cycle testing. Why do Li-ion Batteries die ? and how to improve the situation? by professor Jeff Dahn. One small part of the lecture showed the shortening effect...
by Rory166
Tue Sep 16, 2014 7:19 am
Forum: All things battery related
Topic: Lifepo4 cells . Initial charge or not?
Replies: 6
Views: 8851

Re: Lifepo4 cells . Initial charge or not?

Just watched the recent Jack Rickard Youtube seminar on Lithium batteries. Well tried to watch as it turned out to be an insomnia cure. Anyway I caught a remark that the initial charge should be very slow I think he said several days?

Rory
by Rory166
Sun Sep 14, 2014 10:02 am
Forum: Cars,Vans and other road vehicles
Topic: Zapi H2B regenerative controller for series motor
Replies: 0
Views: 6769

Zapi H2B regenerative controller for series motor

Just downloaded the manual for the controller on my Astra. It seems there is no second pot connection available to control the braking. It is possible to have the throttle pot also influence the braking if programmed in. I do not have a programmer console. There is a speed control mode where a refer...
by Rory166
Sat Sep 13, 2014 8:11 pm
Forum: All things battery related
Topic: Is a BMS actually necessary on LifePo4 cells.
Replies: 6
Views: 16063

Re: Is a BMS actually necessary on LifePo4 cells.

Still thinking about this. It seems to me that the self discharge of Lithium cells whilst low will not necessarily be identical between cells. This over a long period of time will lead to imbalance. If the cells are very well made to tight tolerances then it may be possible for a pack to retain bala...
by Rory166
Thu Sep 11, 2014 7:32 pm
Forum: All things battery related
Topic: Lifepo4 cells . Initial charge or not?
Replies: 6
Views: 8851

Re: Lifepo4 cells . Initial charge or not?

Slight aside I bought a power supply from china which appeared to be ideal for doing the initial charge. http://www.ebay.co.uk/itm/380920543735?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT Unfortunately it does not work correctly. Yes you can set 4.1 V output yes you can set 20A cu...
by Rory166
Sat Sep 06, 2014 3:44 pm
Forum: All things battery related
Topic: Raised Internal Resistance on Hi-power Lifepo4 Cells
Replies: 6
Views: 9159

Re: Raised Internal Resistance on Hi-power Lifepo4 Cells

With lifepo4 cells the term of internal resistance is not really the same as other chemical change cells. Its more a case of lack of flow of current through the cell, rather than pure resistance. Grumpy-b Thank you for confirming that. The Internal Resistance is an element in the electrical equival...
by Rory166
Sat Sep 06, 2014 12:09 am
Forum: All things battery related
Topic: LEAF CHARGER PROJECT
Replies: 18
Views: 20660

Re: LEAF CHARGER PROJECT

More recently it has come to my attention that the 13A plug EVSE charges at 10 amp and even this can overheat standard sockets. For the onboard charger to run at 3.3 KW a 16A charger outlet is required as supplied by Polar etc. My Parents property is blessed with 2 3phase meters so could accommodate...
by Rory166
Sat Sep 06, 2014 12:01 am
Forum: All things battery related
Topic: Raised Internal Resistance on Hi-power Lifepo4 Cells
Replies: 6
Views: 9159

Re: Raised Internal Resistance on Hi-power Lifepo4 Cells

Grenada

I have a 400v 60Ah battery made of these. Some posters on sites have tried to put me off using them with tales of conflagration. They appear similar in construction to Nissan's Leaf cells but different chemistry presumably.

Your post would have warranted it's own thread perhaps?

Rory
by Rory166
Wed Sep 03, 2014 9:30 pm
Forum: All things battery related
Topic: Raised Internal Resistance on Hi-power Lifepo4 Cells
Replies: 6
Views: 9159

Raised Internal Resistance on Hi-power Lifepo4 Cells

I have several 200 Ah cells which have been fitted in 2 vehicles and some not used. The cells have very different voltage under load or IR if you like. The worst having 7 times the resistance of the best. Even the 4 unused cells. One thing that I have noticed is that the pack from inside the 2009 ca...
by Rory166
Sun Aug 24, 2014 7:08 pm
Forum: Home Energy Area
Topic: Using a battery dc source to power the home along with solar
Replies: 4
Views: 6292

Re: Using a battery dc source to power the home along with s

Used lead acid cells should not cost much. Last time I took them to the scrap and got 25p per kilo. As you know the export electricity is usually not metered but you get paid for half what you generate. I am not sure if systems are available to use up the excess from your panels by battery charging....

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