Battery charging

[Phil Dryden]

Hi all,

I've been a cyclist all my life, but I only took up ebiking about 6 months ago. I remember being quite shocked at how hot the charger got when my battery was on charge, yet its something I have never seen discussed on the forum. I have a Bosch 500 powerpack, and the manufacturers own compact charger supplied with the bike. I became so concerned that you can see from the photograph how I charge the battery - a small USB desk fan blowing onto the charger, and the charger resting on 2 pencils to allow the air to circulate around it better. Can someone please tell me - have I totally lost the plot, gone mad, or become so obsessed with all things ebike that I require therapy? Is there another ebiker anywhere in Britain or beyond, who does this?!

 

[Andy-Mat]

Hi all,

I've been a cyclist all my life, but I only took up ebiking about 6 months ago. I remember being quite shocked at how hot the charger got when my battery was on charge, yet its something I have never seen discussed on the forum. I have a Bosch 500 powerpack, and the manufacturers own compact charger supplied with the bike. I became so concerned that you can see from the photograph how I charge the battery - a small USB desk fan blowing onto the charger, and the charger resting on 2 pencils to allow the air to circulate around it better. Can someone please tell me - have I totally lost the plot, gone mad, or become so obsessed with all things ebike that I require therapy? Is there another ebiker anywhere in Britain or beyond, who does this?!

It shortens the life of electronics if it gets as hot as you say it does. You do not need therapy!!! You HAVE common sense!!
But it was was probably so designed. I myself do not like it either.....
The 2 amp charger I got with my bike, actually has a tiny fan inside and runs only slightly warm. It expels the warm air and sucks in fresh air. Not a huge amount, but apparently enough to get rid of most of the heat. Yours looks as though it is sealed.
Are you good with electrics? If yes, maybe you might do what I do occasionally in similar situations, I open up the unit, drill two sets of holes and glue a small CPU fan or similar over one of the holes. Finding suitable power might prove to be a problem.
Do remember though that dust will be deposited inside, so make sure that you can open it up occasionally and run a vacuum cleaner over it. Looks a bit "Heath-Robinson", but it works!!
Or buy a larger plastic Electronic box, transfer all the Electronics to the bigger box, add fan and tiny power supply for the fan(s) INSIDE the box.
Do not use a metal box unless you are able to add a 3 wire mains connection, one with an earth!!
If you are not an electrically trained person, do not do any of this, as it can be quite dangerous....
Better then to buy a new charger, like mine, with a small fan already inside, that should run cooler.
Never do anything with mains power that is outside of your comfort zone.
Its also a good idea to have an RCD for the mains power in every house, but especially for anything portable!! I have one on each of my 3 phases for my house (Germany) and two portable ones as well, just in case!!
regards

Andy

 

[jdallan]

Hi Phil,

I've just taken my 2 Bosch Powertube batteries off charge. They were charging for about 2 hours using what looks like the same charger you have. As usual the charger was warm but couldn't be described as hot.

Jim

 

[Phil Dryden]

Hi Andy-Mat,

Thanks for all the info, but with my limited electrical know-how there is no way I'll be drilling into the charger! Easier just to keep using my twee lil' fan.

Hi Jim,

Maybe the Christmas pudding has addled my brain, and I'm getting over-excited about something that doesn't matter. Its just that, without the fan, the charger is a bit warmer than I am really comfortable with! I'll carry on with the fan, I reckon!

 

[Fat Rat]

Hi
I have the 4a charger with mine
I would describe it when charging as warm to hot
Not in a burning sort of way but definitely more than warm
Im on my 3rd bosch bike and all the 4a chargers have been the same
I wouldn't worry about it myself but what your doing certainly wont hurt

 

[Phil Dryden]

Cheers, Fat Rat!

 

[Deleted member 128]

Hi all,

I've been a cyclist all my life, but I only took up ebiking about 6 months ago. I remember being quite shocked at how hot the charger got when my battery was on charge, yet its something I have never seen discussed on the forum. I have a Bosch 500 powerpack, and the manufacturers own compact charger supplied with the bike. I became so concerned that you can see from the photograph how I charge the battery - a small USB desk fan blowing onto the charger, and the charger resting on 2 pencils to allow the air to circulate around it better. Can someone please tell me - have I totally lost the plot, gone mad, or become so obsessed with all things ebike that I require therapy? Is there another ebiker anywhere in Britain or beyond, who does this?!

Are you able to measure its temperature?

 

[Phil Dryden]

Hi Electrify,

This is when I should be able to say "Ah yes, I'll get out my infra red hand held thermometer gun", point it at the casing and hey presto I have a temperature reading. Retirement has, however, denied me access to these tools of the trade. Anyway, I've stuck another battery on to charge, and sellotaped a small wall thermometer to the casing and the temperature is running around 47℃, maxing out at 50℃. This is a bit unscientific, and may be affected by the fact that the thermometer only goes up to 50℃ anyway. The bulb is not touching the charger casing due to the housing around the glass thermometer - probably 2mm off. Have looked at the charger box and there is no reference to temperature when in use.

 

[Crossroads]

Phil,

I have the same bike/charger/ battery, as you know.

Mine runs very hot as well, it would make a great hand warmer at a football match in December!
I can't hear any fan. It is raised on four feet, I put mine on a table mat as it is too hot to trust on my beech sideboard. The battery seems to stay completely cool whilst charging. I've just checked mine, it's been on for 1.5 hours now, the table mat is pleasantly warm so I think the charger just loses heat through the casing in a controlled way.

I don't think it is anything to worry about and I'm reassured that yours is the same.

 

[Phil Dryden]

Hi Crossroads,

Yes, like yourself I put the charger on a table mat if charging indoors as it would be more than my life is worth to damage the island worktop! I'm not going to bother too much about the charger temperature as it seems to be a normal occurrence. I do think, though, that Bosch could have just mentioned it on the box to set customers minds at rest. Fantastic bike, by the way - just love it.

 

[Crossroads]

Phil,

Glad you posted on the charger issue as I was slightly concerned.

The bike is going strong, I'm going much further and faster and it eats 10% hills for breakfast, so just the job.

 

[Phil Dryden]

Crossroads,

I've just done my last ride for 2018, and topped out at 1,604 miles. Most I've done for a few years now. Done loads of cycling in the past but fitting of ICD last year curbed things a bit. Ebike means I can head out to the north of Leicester where the terrain is a bit more hilly, so happy biker. Extra routes are always welcome.