"how far does a 48V12AH battery go?

[Leslie]

Take it easy for a little bit on a fresh battery so you can cut out some surface area on the batteries plates. You should see the capacity increase over a week then give it some bigger longer loads.


Best of luck.

[Cornelius]

Now, does this apply to LiIon/LiFePo batteries?

Your statement about 'cut some surface area on the battery plates' does indeed apply to lead acid batteries, but... ?!

(or is it just me that hasn't followed the thread here, and he has some LA batteries?   )

[Leslie]

I have read somewhere that new Li batteries do require a break in.  Nothing concrete.  Id say every battery etches the surface area when you charge it until it dies and displaces some of itself into the electrolyte when discharged.  Otherwise it would last forever.

I think its energy related though and voltage drops due to more resistance when the plates are new.



It shows it a little bit here.

[dfmerrifield]

Yes I do know about this and thanks for the luck.  During all my searches and checking out all avenues and products before I bought the MP and my battery, all manufacturers of lifepo4 batteries said the same thing of their products.  They all said that a new battery will have a break in time usually five or more full discharges and charges then the battery will be at a good charge capacity and then get better over time til they start to drop in total capacity.  Some said that the drop in capacity would be anywhere from 500 to 800 charges.  Pretty much as it shows in your chart above.  So by rights the capacity I am going to get right now is pretty much what I should be getting after 500 or hopefully more charges.

Don

[dfmerrifield]

  Hey Guys!

  Did pretty a good running on my MP the other day doing the 20 mph (32 kph) test.  I got over 26 miles on it and didn't die yet, she still had yellow light but, was too tired to keep on going any farther at that time.  I am going to take it to work on Thursday (The weather is suppose to be real nice) and that is 16 miles one way and have to make a small swoop on the way back then see how far she goes then.  I will keep a post an update and maybe this will help others compare to mine and see what they get and go from there.

  Again a Special Thank You to Gary!  You didn't have to do what you did but, it was totally appreciated. (Do pretend I still have an Email).

  "I'd like to see others post their results and let everyone know what they get so as to let us all know what the end results are."

Don

[dfmerrifield]

Hey Gary and everyone else!

  Gary, I told you about the charging problems I was having with my system?  Well, I had always charged my battery by plugging the charger into the wall first, then into/onto the battery secondly.   After talking with you a bit back, you said; "Plug the charger into the battery first then plug the charger after".  Well I did that for the last while, thinking maybe all I have been taught was off but more, that maybe it's the type of battery (LiFePo4 type) that needs things done differently.  From what I have experienced lately, I was right in the first place.  

  I was charging my battery by doing it my normal way, the wall first then the battery, thus the charger reads the battery then turns on as needed.  Doing it this way, I was getting (depending on the winds) 20 to 23 miles per charge at full speed all the way through with no problems til' she stops.  After doing it the other way of plugging the battery in first then the charger into the wall, for some reason, I was only getting 16 miles average and then stop dead.  I know this sounds off the wall but, that is what I have been getting!

  After we talked on the phone this morning about my order for a second battery for my bike, I sat back and thought about what I was doing differently than when I first got my replacement battery and why I was getting such a difference in mileage.  So, I tried it my way and went for a run to do a couple of errands and got my old 21 miles on a charge by plugging the charger first into the wall.  Seems the charger needs to be active to know what the battery really needs.  It seems that way anyways?  Well, I got good or better distance out of her after changing it my normal way, any how.  Give it a try and see how it works on yours!  You may get better running's out of yours too!

  Anyway, I can't wait to get my second battery!  I am going to the bank tomorrow and do the transfer to you so I can get my parts as fast as possible.  With 20 amps continuous at 12 ah and 30 amps at 16 ah, I can't wait to see how she runs with 24 amp hour!  Anyway, I have sent an email to you with some info and if you can get back to me soon, it would be appreciated.

Don

  

[Leslie]

Its good to have the current ready to go downhill not up.

Meaning I would plug into the wall first and then to the pack.

All the regulators and chargers I build and stuff I always put a blocking diode on the output if the built device had to go on a battery,  EG The output conncects to a battery that has its own power source, Just to block the battery current surging back into the circiut if the regulator becomes unplugged from its input power source.

Current can only go in or out never both ways and that depends on your voltage out to in.  You can have 1 milliion amps at 48v and 100ma at 48.1v and the current will always travel towards the lower voltages.

Just think about how much current your pack gives compared to the charger and where that current wants tyo go when the charger is switched off the wall.

With no higher voltages present in the charger the current wants to run backwards,

The other way, the chargers voltage when switched on is another very solid protection for the charger.  Most of the diodes modern charger are up for a few good hits but they are not light speed and I always fear that some spikes get through.

Like intermitant GPO wall connections "zshhttt zshhht" can be hazardous to the output switch because this arc behavior could well exceed the switching speed of any passive component that we need to operate under no input power.

Just my 2c.

[Leslie]

Yeah I just thought of the cure and probably another 100 folk before me.

Is have the charger battery powered and not AC powered.

This way you can use fets as protection and king of the current is in controll.

Only then I would plug the charger into the pack first.

[GM Canada]

Hi Don

I have tried both methods on and off now for about a week and I can find no difference. Since I have my chargers permanently mounted on my bike I think Ill just stick to my method. I do enjoy just pulling the plug out of the pouch and plugging it in to the nearest receptacle in a very care free manour . If you look at the picture you can see I have one charger mounted in a pouch under the seat another in a pouch on the front handle bars and the pouch at the bottom by the pedals contains a 20 foot cord for plugging it in. Anyway, the only thing I really ever notice is the more I run down my batteries before charging the better the charge I get.

Gary