crwdns2933803:02crwdne2933803:0
crwdns2933797:0Dave Empsoncrwdnd2933797:0crwdne2933797:0
crwdns2936043:0crwdne2936043:0 crwdns2933505:0crwdne2933505:0 Dave Empson
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crwdns2933807:0crwdne2933807:0
| [title] Check voltage the 6 cells | |
| - | [* black] Image shows battery pack with lid, screws and green buttons |
| - | [* black] You can remove the cells and the (BMS) circuit board assembly from the housing, but be careful with attached wires. You can remove the 4-pin connector to make it easier, but mine was glued (hot waxed?) |
| - | [* black] You now have access to the inside terminals of the power connector and can check that there is about 27V there with the charger turned on. I had 0V getting though until I cleaned the connection with 'electrical contact cleaner' and pushed the plug in and out about twenty times until I could see a voltage getting though with a multimeter. |
| - | [* black] If poor connection was the only problem, you should see the led's light up as charging begins. (If you have a model without LED indicators, a power meter will show the charger taking about 15W. If you have no power meter you should notice the mains charger getting warm after 5mins or so.) |
| + | [* black] Image shows opened battery pack with lid, screws and green buttons. It also shows the little partially-charged Li ion cell (ex e-cigarette) I used to give an initial charge to the 6 cells in the battery pack, one at a time. |
| + | [* black] You can remove the 'cells and the (BMS) circuit board' assembly from the housing, but be careful with attached wires. You can remove the 4-pin connector to make it easier, but mine was glued in (hot waxed?), so I left it in place. The power connector socket just pulls out from the housing, once the above assembly is partially removed. |
| + | [* black] You now have access to the inside terminals of the power connector socket and can check that there is about 27V there with the charger turned on. I had 0V getting though until I cleaned the connection with 'electrical contact cleaner' and pushed the plug in and out about twenty times until I could see a voltage getting though with a multimeter. |
| + | [* black] If poor connection was the only problem, you should see the led's light up as charging begins. (If you have a model without LED indicators, a power meter will show the charger taking about 15W. If you have no power meter you should notice the mains charger getting touch warm after 5mins or so.) If charging does not begin carry on with steps below. |
| [* black] With a multimeter check the voltages of all 6 cells. Mine varied between 0.76v and 0.91v. At this low voltage the BMS believes the cells are very old or are partially shorted, so for fire safety reasons, it will not charge them. | |
| [* black] If all the cells are in very good visual condition and you know they haven't been charged for a long time and all the cells have a similar voltage, you can attempt to revive them at your own risk. Read further online for risks. | |
| [* black] Using a multimeter, mark the ends of each cell which are positive. With a single Li ion battery (as in the image, with soldered wires attached eg from a discarded e-cigarette), touch positive to positive and negative to negative for a couple of seconds for each cell. You may see a tiny spark or puff of smoke at the contact points. | |
| [* black] In my case the voltage of each cell rose to about 3 volts. You can now attach the charger. With the cells outside their housing, you can feel if they get hot. If they do, stop immediately and abandon this repair. In my case the cells were all cool and charging continued for 4hrs until the green LED's stopped flashing. |