Battery Charger Fun - Sans 42volt 2amp

[anotherkiwi]

It is written on them they are good for up to 105°C. But with the cover on and no fan I can see you going over that...

 

[cyclebuddy]

Hi cyclebuddy

Now my pack is back up and running I still feel the charger is getting too hot even with the top cover removed.

After playing around with a digital thermometer confirm am getting the highest temps of 60c at the two 50v caps...can only imagine what temp they are getting to with the cover on...must be like an oven in there! Am also seeing 45c on the main aluminium 'heat sink'

Playing a simple desk fan onto the bare circuit board see this value drop to a more desirable 30c and appear to be getting better charging performance as a result.

Am going to upgrade the two 50v caps to the Panasonic 63v 470UF 105C EEUFC1J471 per your post

Carrera Crossfire ebike Battery Charger

Though will still likely use the desktop fan to keep things cool.....not an issue as charging at home.

Glad to hear your battery is fixed.

I didn’t have the foresight to measure temperatures before and after changing those caps, but with the further addition of sticking large rubber feet to the base of the charger (to raise it off the surface allowing air to circulate) I’d say my own charger seems to be running a little cooler now.

I’ve fixed a few power supplies and battery chargers always using Panasonic Low-ESR caps, and they’ve proven to be 100% reliable. IMHO, it’s worth doing before something causes the existing cheapies to go splat.
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[grahamx]

Glad to hear your battery is fixed.

I didn’t have the foresight to measure temperatures before and after changing those caps, but with the further addition of sticking large rubber feet to the base of the charger (to raise it off the surface allowing air to circulate) I’d say my own charger seems to be running a little cooler now.

I’ve fixed a few power supplies and battery chargers always using Panasonic Low-ESR caps, and they’ve proven to be 100% reliable. IMHO, it’s worth doing before something causes the existing cheapies to go splat.
​

Thanks for your assistance thanks for reminding me about the larger rubber feet.

Replacing the caps seems both a worthwhile and cost effective upgrade.

Have ordered 2 of the Panasonic 470uf 63v 105c EEUFC1J471 off ebay for under £3 delivered

Have not replaced caps on circuit board before but I have soldering iron kit and there are plenty of youtube videos on the subject regarding checking polarity / desoldering/ replacing etc

I note they are rated at 105c and are 16mm wide compared to the existing 9mm wide caps......appears adequate space to fit on my sans board version.

Will be interesting to see at what temperature they operate at compared to the existing caps.

 

[grahamx]

Just to update fitted the Panasonic 470uf 63v 105c EEUFC1J471 Caps and all went ok

Reckon they will cope better with the high temps this charger produces.

Temperatures are pretty much the same as the replaced caps circa 60C though with my usb desk fan temps down to 27-28C.

Will continue to run the desk fan for this charger.

 

[Planemo]

Great thread guys, thanks for the info, I wasnt aware of this potential issue. I have just ordered 2 of the caps mentioned (£2.89 delivered on the bay) and will fit them into my Oxydrive 2A charger for peace of mind.

 

[grahamx]

Great thread guys, thanks for the info, I wasnt aware of this potential issue. I have just ordered 2 of the caps mentioned (£2.89 delivered on the bay) and will fit them into my Oxydrive 2A charger for peace of mind.

Yes that's the same seller I used...got good service arrived quickly

https://www.ebay.co.uk/itm/470uf-63v-105c-LOW-ESR-Size-16mmx20mm-Panasonic-EEUFC1J471-Low-profile-x2pcs/300515085094?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

I didn't have as much clearance between other components in my charger compared to @cyclebuddy but plenty of headroom to allow me to raise these caps a few mm and tilt at slight angle to avoid any contact.

Good luck with your install.

 

[Planemo]

All done, thanks again to all. To get a better fit I just offset the legs using some needle nose pliers. 10 minute job in all. Hopefully my charger is less likely to go kaput now. Few pics: standard caps, offset legs on caps and new caps fitted:

 

[wheeliepete]

Nice neat job, almost makes me wish I had one of those chargers, any excuse for a bit of tinkering.

 

[Charliefox]

I'm running a standard Sans 42Volt 2 amp charger as supplied with an Oxygen S-Cross w/ 36V 13amp battery. I understand the Sans from google search is a basic/ cheap charger.

The bike is a year old and had covered 40 miles when I purchased it. I have put another 80 miles on it since ownership.

Charger outputs 42.1v (tested with multimeter) and has successfully (on 3 occasions) charged the battery up to 42v . Charger shows green light plugged into mains only/ red light during charge/ green light at finish.

Did notice the charger was getting particularly hot to touch during charging so I raised it on a wire baking tray in attempt to assist with airflow. Also I noticed that the final stage of charge ramping down took 90mins! determined with my plug in watt meter which btw is a great way to know what the charger is up to

Unfortunately the charger failed to charge the battery on the last charge & just stayed on green light when connected to battery....I didn't realise this untill following days ride where I had been lazy to check final volts!

Have taken a look at the inside of the charger but cannot see any obvious evidence of blown components

UPDATE

More luck then anything else .....after connecting and disconnecting the battery a few times this afternnoon I saw a brief red flicker from the charger and now it appears to be back up and running again. I've left the top section charger case off to assist with the heat issue and am carefully monitoring battery charger with my watt meter as well as battery volts with multimeter.

Will update how the rest of the charge goes...... and will definite not be using this charger unattended

Has anyone else similar issues / fixes/ modifications of this charger?

I have a Sans Charger with a circular connector, inner pin + and outer ring -. Sometimes I have to rotate it a little if the light stays on green when the battery needs charging. Once the battery side connector came loose and needed tightening which didn't help. My charger always gets hot on charging but lasted 3 years so far.

 

[grahamx]

All done, thanks again to all. To get a better fit I just offset the legs using some needle nose pliers. 10 minute job in all. Hopefully my charger is less likely to go kaput now. Few pics: standard caps, offset legs on caps and new caps fitted:

Nice job with those offset caps.

Are you planning anything extra to cool the charger?

Run mine top cover removed and cool circuitry with 12v desk fan. Gives me peace of mind when on charge.

 

[Planemo]

Hi Graham, no I hadnt gone as far as additional cooling, and I am not keen on the hassle of removing the lid every time I charge, nor having to run a fan if I am honest. My charger gets chucked in a box with 3000 other chargers as well, so I cant leave it exposed permanently. I am considering 'swiss cheesing' the entire case, so at least it will get some air throughput, and if there is as much heat being generated as you say, then convection currents should assist with dragging the air through. I may run some thicker rubber feet as well to pull it up of the desk and help with air movement through the bottom and out the top.

 

[Planemo]

Completed the Heath Robinson treatment today. I thought that some ventilation might help, so out came the 10mm drillbit, 48 and 40mm hole cutters. I hot glued some old mesh I had lying around on top to prevent prying fingers/large debris falling in. I contemplated putting mesh on the bottom as well but its proximity to the PCB worried me, plus its not really necessary anyway. A bit of time and zero cost. Hopefully it will help!

 

[Planemo]

Hi Cyclebuddy, given the capacitor upgrade to my charger, it got me thinking about the wifes one which is a Heng Guang Power 36v 1.6a.

I thought it would be similar to mine but on opening it up I found it was quite different, with only one of the smaller caps which is a 50v 330uF (less than the 470uF I took out of my old charger!)

Is it worth fitting one of the same, larger caps that I put in my charger do you think? The other large cap in my wifes charger is a 400v 47uF but I do not think this is anything to do with the circuit in question?

 

[cyclebuddy]

Hi Cyclebuddy, given the capacitor upgrade to my charger, it got me thinking about the wifes one which is a Heng Guang Power 36v 1.6a.

I thought it would be similar to mine but on opening it up I found it was quite different, with only one of the smaller caps which is a 50v 330uF (less than the 470uF I took out of my old charger!)

Is it worth fitting one of the same, larger caps that I put in my charger do you think? The other large cap in my wifes charger is a 400v 47uF but I do not think this is anything to do with the circuit in question?

The issue with the sealed case Sans charger is that it works very hard for long periods and gets hotter than many seem comfortable with. Capacitors tend to dry out/rupture/fail prematurely when used that way. For cooling, just adding some big rubber feet onto the base is enough to get some air under the charger and help dissipate that heat from a large-surface side of the case that otherwise doesn't allow any heat to escape. I'd be very careful with the cooling holes you've drilled in yours as you're exposing yourself to very high voltages on the input side.

Capacitors also work more comfortable/reliably if there's decent margin over the working voltage: As the charger output voltage is 42/43v, uprating the cheapy 50v smoothing caps to quality 63v ones is, I think, a very good idea as they would often fail first.

I don't know your wife's brand of charger, but your pic shows it's very basically constructed. At 1.6A, it's also lower power so may not get as hot?

If the charger output is 42v (i.e intended for a 36v battery), changing the 50v output cap to an equivalent-rated 63v one may help, but there's no need or benefit ever to changing the 400v cap on the primary side.
​

 

[Planemo]

Thanks cyclebuddy. I will see if I can find a 63v 330uf to replace the single 50v 330uf. I am not sure if it gets hot, tbh I am not around either charger when they are working as they are always down the shed. Another reason why I wasnt fussed about drilling holes in mine, no one is likely to go near it.

 

[grahamx]

Completed the Heath Robinson treatment today. I thought that some ventilation might help, so out came the 10mm drillbit, 48 and 40mm hole cutters. I hot glued some old mesh I had lying around on top to prevent prying fingers/large debris falling in. I contemplated putting mesh on the bottom as well but its proximity to the PCB worried me, plus its not really necessary anyway. A bit of time and zero cost. Hopefully it will help!

Well done Planmeo...essential upgrade especially in this heatwave. I'm going to tinker further at some point with my case and have added it to my jobs to do list.

 

[Charliefox]

The issue with the sealed case Sans charger is that it works very hard for long periods and gets hotter than many seem comfortable with. Capacitors tend to dry out/rupture/fail prematurely when used that way. For cooling, just adding some big rubber feet onto the base is enough to get some air under the charger and help dissipate that heat from a large-surface side of the case that otherwise doesn't allow any heat to escape. I'd be very careful with the cooling holes you've drilled in yours as you're exposing yourself to very high voltages on the input side.

Capacitors also work more comfortable/reliably if there's decent margin over the working voltage: As the charger output voltage is 42/43v, uprating the cheapy 50v smoothing caps to quality 63v ones is, I think, a very good idea as they would often fail first.

I don't know your wife's brand of charger, but your pic shows it's very basically constructed. At 1.6A, it's also lower power so may not get as hot?

If the charger output is 42v (i.e intended for a 36v battery), changing the 50v output cap to an equivalent-rated 63v one may help, but there's no need or benefit ever to changing the 400v cap on the primary side.
​

I know we are a few years on from this post BUT! I wonder if you could help since you seem to know your way around SANS chargers. I just came home and plugged mine in (42v 2amp model) It was green on switch on, turning to red as per usual but for only 5 seconds then reverting to green. Battery was not charged fully as I'd just done a run. I wiggled the female connector to the battery and the same cycle happened. Tried same again a fewmore times and the house circuit (5 amp) blew. I have another, same model as I have a spare battery, so tried this after fixing the fuse. It worked fine although I noticed the power lead plug of both Sans had 13amp fuses in their plugs which I changed to 3 amp ones.Back in the house I managed to get a reading of 42v from the battery connector end for the brief 5 seconds the green light was on (charger NOT connected to any battery) Was it also my imagination or did the green go off before 5 seconds if I shorted the centre pin with the circular -ve around it using just my finger?
I suspect something internal has gone wrong. It would be nice to fix as the other charger may go the same way and both have this odd right angled female battery connector which is hard to find online.