charger keeps cycling

[m3vuv]

hi all i have a5 amp evergreen charger originaly for an 18s lithium ion pack,i wound the voltage down to 54.6 for my 13s pack and set the current to 5a using the pots inside,however i notice as soon as the pack gets to 53v the charger goes green,it stays like that for maybe 3 seconds then turns red again for say 3 seconds and repeats,any ideas as i find it hard to get the pack fully charged 54v is about max,should i adjust the charger voltage with the pack connected ?,as i set it up disconnected from the battery,TIA m3vuv.

 

[amberwolf]

Sounds like typical behavior for a pack with a balancing BMS doing the balancing stage. That can last for hours to days to weeks, depending on how bad an imbalance it is.

What kind of BMS do you have, and what are the conditions of the cells?

Did the pack work correctly with it's original charger?

hi all i have a5 amp evergreen charger originaly for an 18s lithium ion pack,i wound the voltage down to 54.6 for my 13s pack and set the current to 5a using the pots inside,however i notice as soon as the pack gets to 53v the charger goes green,it stays like that for maybe 3 seconds then turns red again for say 3 seconds and repeats,any ideas as i find it hard to get the pack fully charged 54v is about max,should i adjust the charger voltage with the pack connected ?,as i set it up disconnected from the battery,TIA m3vuv.

 

[m3vuv]

its a homemade pack using a jtl bt smart bms,the cells are samsung 15q 1500mah,nearly new,sorry but you tell me what i already know,i realy need to know should i set the charge voltage with the pack connected,ie to compensate for voltage sag under load,that is the main point of posting the question.

 

[john61ct]

54V is actually perfect as FULL for 13S

Nothing to be gained going higher just lifetime cycles reducing stress

 

[m3vuv]

i already know that but it doesent answer what i asked tho,ie should the charger voltage be adjusted with the charger loaded or unloaded?

 

[john61ct]

An accurate DMM at the battery posts while charging should be the reference, assume your charge termination is just based on voltage (CC only)

An ammeter is required if holding Absorption / CV stage down to a certain trailing amps.

Adjust the charger until you get your desired result profile.

 

[TommyCat]

I’ve found this thread helpful in understanding a typical charger operation and adjustments…
https://electricbike.com/forum/for...-to-adjust-the-luna-charger-mini-and-advanced



Regards,
T.C.