Tuesday, December 22, 2009

Another change of plans

I received the booster pack batteries from Doctorbass on the endless-sphere.com forums. However, I found out that these aren't enough to create a strong and equivalent booster pack for my 37V 13AH main Bosch Fat Packs. I would need another 6 or so packs bringing the total cost up to the mid $150 range. I've decided to bag that for now and switch to a 72V configuration with the rear 9C motor. This should give me the necessary range and speed to get me to and from work.

More later,
Ambrose

Thursday, December 10, 2009

Booster packs have arrived!


After a two week wait, my Konion/Sony/Makita 18V booster packs have arrived from Canada. These added to my 37V packs should give me around 55V of voltage instead of the 48V that I have now with my Bosch Fat Packs and 12V SLA battery. I need to open them up to get to them. These packs are labelled Makita, however, they have the Sony/Konion cells inside. These packs are from a battery repair/return place and salvaged for their (hopefully) good cells inside. They are all fairly well used (if you can conclude anything by looking at their cases). All of them have issues. Either one or more of the cells in the packs are bad or the battery management system board (BMS) has gone bad. It's easy to find out. If each of the cells measures over 3V individually then, they are ok. If they are under 3V, then they have died. If all the cells test OK, then it's the BMS board. Simple!

I discovered that they are screwed to each other with Torx TR screws. The TR stands for tamper resistant. They have center pins in the middle of torx hole so that a normal Torx screwdriver won't work. The bit can't sink fully to engage the screw. I've just ordered a Torx TR set to open these up.

As you can see, they are considerably smaller than the Bosch Fat packs on the left. The Makita packs only contain 5 cells, I believe. I'll let you know once I open them up.

More later,
Ambrose

Tuesday, December 1, 2009

Rain, rain again...

Well, it's been raining solidly for over a week here in DC... at least on work days. I was out sick yesterday with a sore throat and the weather today is gorgeous, but chilly. The temperature was 33° F this morning. That's less than 1° C! The thought of riding with a sore throat at that temperature just wasn't appealing so I bagged it for today. I'm waiting for my Bosch booster pack cells to arrive. The plan is to add 6 18V 13.2AH packs to my 6 37V 13.2AH pack for a total of 55V 13.2AH. That should give me a nice speed boost and also add to my range a bit. The 12V lead acid battery booster pack isn't giving me it's full 18AH of power so I run out at the most critical point near the end of my 13 mile commute. Hopefully this will give me all 13.2AH of power at 55V. I'll report back when I find out!

More later,
Ambrose