Lafree SP1 Charger problem

[aaannndddyyy]

Hi I have a Giant lafree with an SP1 Charger which has been working fine untill today, now when it is pluged into the mains the red led flashes 3 times, weather it is pluged into the battery or not but will not charge the battery can anyone give advise please.

 

[flecc]

The original Panasonic chargers for the Lafree were notoriously unreliable Andy, and also unrepairable, but I suspect that one you have there might be a Metco made one that you might have got from me originally.

Could you confirm which it is? The original Panasonic one is rectangular, the Metco that replaced it for a short while was a triangulated shape.
.

 

[aaannndddyyy]

It is a Metco, but not the one I got from you this is another Lafree.

 

[flecc]

That's a coincidence, the Metcos were only supplied for a while pending Panasonic sorting out their one, both Lafree's possibly around the same age.

I don't know of any repair possible on that Metco, so a new charger might be the only answer. Giant's one costs around £125, but the one from Powerstream which I've used successfully as a replacement is much cheaper, even with today's exchange rates.

Latest price is £40.41 today after conversion from $US, plus postage by USPS Express service brings the total to £68.29. All the details are on the page below on my Lafree website:

Lafree charger replacement

Make sure you scroll down and change to the cheaper postage on the first page after clicking "add to cart", or the most expensive post option will be charged. The part number of the one needed is PST-3PN9530-24-3A
.

 

[aaannndddyyy]

Thanks for that Flecc the 1.8 amp charger is no longer stocked, but the 3 amp charger will work.

 

[Cyclezee]

Hi Andy,

I think there is currently a Panasonic Lafree charger on eBay. Could be a bargain.........or not!

J hn

 

[PaulC]

Q: is 3Amp charger too powerful?

Reawakening this thread as I have just come across it:
Wouldn't the 3Amp charger be too powerful for the Giant LaFree 6.5AH NiMH battery pack?
Paul

 

[rog_london]

Reawakening this thread as I have just come across it:
Wouldn't the 3Amp charger be too powerful for the Giant LaFree 6.5AH NiMH battery pack?
Paul

Probably no problem - the current the charger is capable of delivering would be largely irrelevant. It's the voltage which would be important. You might get a shorter charge time, but generally you can charge NiMH high-discharge batteries at anything up to their rated discharge current.

To be absolutely certain, you'd need to know how the charging was controlled, and how it was stopped when the battery was fully charged. If there's a BMS, definitely no problem.

Rog.

 

[flecc]

As Rog says, no problem and the charge time is no different with either of the chargers on the Lafree battery. They both charge at the same rate controlled by the NiMh cells internal resistances, regardless of the 3 Amp one being capable of more.

There are a fair number of both ratings of those Powerstream supplied Shenzhen chargers in use with Lafrees worldwide following my site recommendation since 2006.
.

 

[brianandsusan]

Andy,
Apologies for picking up on this old thread but I have experienced the same problem with the Metco charger flashing 3 times when plugged in and then no charging occuring. Did you solve the problem or did you resort to buying a new charger ?
Thanks
Brian

 

[miau]

Inside the battery there are two fusibles: one for over-current, which is a car fusible, and another one is for overtemperature. They are both on the load circuit.
I have replaced the first one twice (I don't remember the symptoms, but I think the charger did nothing) and I have short-circuited the second when the Metco charger blinked 3 times. If you really want to replace (instead of short) the temperature fusible, it is a MICROTEMP G4A50, 250V, 10A, Tf=104C, holding temperature 79C (http://en.wikipedia.org/wiki/Thermal_cutoff).

The current fusible is very visible when you open the battery, while the thermal fuse is exactly in the middle of the battery, so you need to cut open the plastic sheet and pull it out. It is along the red wire that comes from the charger.

 

[brianandsusan]

Inside the battery there are two fusibles: one for over-current, which is a car fusible, and another one is for overtemperature. They are both on the load circuit.
I have replaced the first one twice (I don't remember the symptoms, but I think the charger did nothing) and I have short-circuited the second when the Metco charger blinked 3 times. If you really want to replace (instead of short) the temperature fusible, it is a MICROTEMP G4A50, 250V, 10A, Tf=104C, holding temperature 79C (http://en.wikipedia.org/wiki/Thermal_cutoff).

The current fusible is very visible when you open the battery, while the thermal fuse is exactly in the middle of the battery, so you need to cut open the plastic sheet and pull it out. It is along the red wire that comes from the charger.

Miau, I solved the problem eventually in February and the problem seems similar to what you report. However the devices I had problems with were on the over-temperature circuit. This has a thermister and a thermal cut-off device. Both devices failed. Circumstances of failure were I topped up the charge on the battery and kept it charged for perhaps 2 or 3 hours after it needed to be - certainly the battery pack was very warm. So I guess the device did its job in preventing the battery pack from overheating. The thermal cut-off is a Microtemp I4A50, 250V, 10A although I may have misread the labelling as it is very small.

I replaced the thermister but have not replaced the thermal cut-off device. I now monitor the charging process and pack temperature. There was an additional problem, perhaps related to the overheating, where cells 1 & 2 (at the +ve end) would not take charge. I replaced them.
Brian