Guru
Joined: 15/07/2006
Location: AustraliaPosts: 676
| Posted: 09:26am 04 Feb 2012 |
Time to catch up a bit
It has been a long time since I said I had ordered a commercial quantity of single cell chargers. Well, because we discovered that they stopped charging after a while, and needed a resister in the output, we asked the manufacturer to add the resistance. They refused. I cancelled the order and took close on 6 months to get my money back. Thankfully they did eventually refund it.
I was not keen on spending the time to add the resistance and have a product with reduced output current as a result. I still had to do the packaging. With the original test circuits, I used heat shrink over the circuit and base board, with potting in both ends to seal it up from dirt and water. All this hand work would make them too expensive for sale.
A new supplier and a new product were found for single cell charging. The output of these chargers is 3.7vdc. Input is pack voltage, 167vdc.
I set about installing them. All the input wires were connected in parallel. The input was to be switched through a solid state relay from the Zivan NG3 charger. The relay fried itself before I even connected it up properly. I tested the function by holding the coil wire (12v) and the output just went closed circuit, but would not reopen. So the test was conducted by manually switching the 3.7v chargers on.
When you look at all the wire it looks a bit scary. But just work on one at a time and it’s all easy connecting. It doesn’t look so bad when all cable tied neatly.
Test 1
The Zivan charger was to charge to it normal voltage of 167vdc and holding battery pack voltage, the 3.7v chargers are switched on. The high volt cells do not get charged, because they are higher than the 3.7v output of the charger, but drain off because the chargers on the low volt cells are taking power to charge. The idea was to get them all to be of similar voltage.
The pack at 167v, the highest cell, no.6 at 4.07v and the lowest cell, no. 35 at 3.58v. Only the highest and lowest cell was monitored until it was evident that it was not working. Note, cell voltage come down but then go up. Cell voltage go up but then come down. Output of the chargers were not stable and fixed. Mostly however the cells remained fairly close together in voltage, but not reliable with a number of cells going haywire.
Edit: attempting to see what happens with resizing pictures.
Pictures need to be 501 pixels wide or more to get the watermark.
Pictures above 500 pixels wide will auto resize to 500 pixels wide.
Pictures need to be 390 pixels wide to fit 2 side by side with a space between them. No space to picture underneath.
To get the water mark on pictures smaller than 501 pixels, upload as normal. Copy the picture, resize to required size and edit post, re-uploading picture with watermark. Or put your own watermark on first.
I used to have all my posts with pictures side by side. New software changes the rules.
Scanned the graph with different dpi trying to get it bigger, but makes no difference to view size when uploaded.
To view bigger, on your web brouser, click tools, click zoom.
Trev @ drivebynature.com