XPR7550 dead Impres lithium battery and flashing red light
Posted: Sun Sep 03, 2017 9:34 am
I attempted to charge an XPR7550 lithium battery which had not be charged for maybe 12 months and was completely flat (0.01v)
The standard Impress charger just gave a flashing red light. I left it for an hour or so as I assumed that the charger was "intelligent" and would attempt to "trickle charge" the battery from zero volts to whatever level the charger needed to start the fast charge routine. However the red light just kept on flashing. However there was some voltage being pulsed into the battery but the battery voltage did not appear to be increasing.
So I used a 12v 150mA trickle charger (from an old Yaesu FT290) to force a charge into the battery. I used the "inside" battery pads ( which connect to the actual radio) and had my meter in line so I could measure how the voltage was slowly increasing.
Under no load, the trickle charger measured 20v but when connected to the battery this fell to a couple of volts and started to increase very fast up to about 5 volts and then continued to slowly rise. At 5.5v I thought that this was enough voltage for the charger to recognise the battery and to start the charging routine. When I connected the battery I got a steady red light...but a few minutes later it was back to a flashing red light? So I reconnected the trickle charger and held it in place until the voltage was up to around 7.00v - this took about 15 minutes. When I again placed the battery in the Impres charger I now got a yellow conditioning light (which I did not want as I guess it starts to discharge the battery??). Anyway, I took the battery out and then put it back in (which is what you do if you don't want to go into the conditioning routine) and the red light came on and the battery now appears to be charging OK.
If I had left the 0v battery in the charger "flashing red" overnight, would the battery have eventually charged up or did I have no option but to force a trickle charge into the battery?
The charger is still on red so lets hope its now fast charging OK!!
The standard Impress charger just gave a flashing red light. I left it for an hour or so as I assumed that the charger was "intelligent" and would attempt to "trickle charge" the battery from zero volts to whatever level the charger needed to start the fast charge routine. However the red light just kept on flashing. However there was some voltage being pulsed into the battery but the battery voltage did not appear to be increasing.
So I used a 12v 150mA trickle charger (from an old Yaesu FT290) to force a charge into the battery. I used the "inside" battery pads ( which connect to the actual radio) and had my meter in line so I could measure how the voltage was slowly increasing.
Under no load, the trickle charger measured 20v but when connected to the battery this fell to a couple of volts and started to increase very fast up to about 5 volts and then continued to slowly rise. At 5.5v I thought that this was enough voltage for the charger to recognise the battery and to start the charging routine. When I connected the battery I got a steady red light...but a few minutes later it was back to a flashing red light? So I reconnected the trickle charger and held it in place until the voltage was up to around 7.00v - this took about 15 minutes. When I again placed the battery in the Impres charger I now got a yellow conditioning light (which I did not want as I guess it starts to discharge the battery??). Anyway, I took the battery out and then put it back in (which is what you do if you don't want to go into the conditioning routine) and the red light came on and the battery now appears to be charging OK.
If I had left the 0v battery in the charger "flashing red" overnight, would the battery have eventually charged up or did I have no option but to force a trickle charge into the battery?
The charger is still on red so lets hope its now fast charging OK!!