Navitron Renewable Energy and Sustainability Forum

Energy/Electricity Storage and Use/Grid Connection => Off-Grid, Batteries & Inverters => Topic started by: billi on January 10, 2018, 04:48:16 PM



Title: Found a battery at the dump
Post by: billi on January 10, 2018, 04:48:16 PM
Found that battery thrown away ....
Thought  maybe usefull  , today I finally got my multimeter out to check but nothing  banghead:  opened the case and measured 26.2 volt on to me obvious + and- cables
It's a 24 volt  li.... battery   has anyone an idea how to charge that diectly  and why I could not measure anything on the on your poles that obviously looked to me hooked to the el motor of the bike .... must be a start and stop connection   ...
Anyway  , where is the Bms ?
Thanks Billi
(https://s18.postimg.org/swbdbrek5/20180110_140824.jpg) (https://postimg.org/image/swbdbrek5/)

(https://s18.postimg.org/5i3dzv6xh/20180110_132222.jpg) (https://postimg.org/image/5i3dzv6xh/)


Title: Re: Found a battery at the dump
Post by: biff on January 10, 2018, 05:28:42 PM
Hi billing.
    If you Google their web site. They might supply you with a charger . The control circuit is under the lid.. you might find that all is wrong is a broken connection.
        Biff


Title: Re: Found a battery at the dump
Post by: Tiff on January 10, 2018, 07:35:41 PM

It's a 7s pack of 18650 cells. Charge to 4.2v per cell for max capacity or 4.0v for maximum charge cycles.

A cheap charger would be a B6 charger from ebay but will only charge up to 6s so you would need to charge the pack in two sections. You can get get balance leads cheaply to add on, I would imagine the leads are already there.


Title: Re: Found a battery at the dump
Post by: rogeriko on January 10, 2018, 09:11:13 PM
Pull it apart and you will have lots of 18650 cells. Some will probably be bad but most will be good. Buy a 18650 charger and charge the cells individually and use them in flashlights, headlights, bicycle lights all sort of things. You could probably get 30 pounds for it on ebay,   treasure :hysteria :hysteria


Title: Re: Found a battery at the dump
Post by: billi on January 11, 2018, 04:34:56 PM
.... there are in total  42 cells  max charge is upto 29.4 Volt  so a  24 volt chargecontroller should work on the whole pack .... 

connected a 24 15 watt light  will see how much the votage drops  over time  ,  total capacity is 0.25 kW  nominal voltage is 25.9 V 

So to what voltage can one discharge without harm ?

Thanks Billi
(https://s10.postimg.org/ee54ukng5/26678314_1951954635123862_2904206177889173310_o.jpg) (https://postimg.org/image/ee54ukng5/)


Title: Re: Found a battery at the dump
Post by: Fionn on January 12, 2018, 02:17:54 PM
Hi Billi,

Buy one of these - https://www.ebay.co.uk/itm/272655533459
And put some of the good cells from that pack into it and it will solve your problem from here: https://www.navitron.org.uk/forum/index.php/topic,29155.msg331465.html

Hope that helps!

Fionn.


Title: Re: Found a battery at the dump
Post by: billi on January 12, 2018, 03:18:18 PM
Good thinking  ,  Fionn   something like that is in my head ;)


Title: Re: Found a battery at the dump
Post by: Tiff on January 12, 2018, 06:38:39 PM
.... there are in total  42 cells  max charge is upto 29.4 Volt  so a  24 volt chargecontroller should work on the whole pack .... 

connected a 24 15 watt light  will see how much the votage drops  over time  ,  total capacity is 0.25 kW  nominal voltage is 25.9 V 

So to what voltage can one discharge without harm ?

Thanks Billi
(https://s10.postimg.org/ee54ukng5/26678314_1951954635123862_2904206177889173310_o.jpg) (https://postimg.org/image/ee54ukng5/)


Stop at around 3v per cell, the discharge for lithium is very flat, until you get to the knee when it drops rapidly so you need to keep an eye on it.