hmmwv
Newly Enlightened
Just a quick followup note - after 4 charge/discharge cycles, the 1st prototype 9N Sanyo 3000RC pack is producing 77 minutes of runtime, 13 short of the (hoped) 90 - but I have 5 more protos to build, so it will be interesting to see how they vary -- I know that among cells, there can bee a several hundred mah variation - the next pack will be made from matched cells with the highest MAH off the battery tester before assembly to try and get the runtime higher. It'll be a while because I must put each cell in the tester and run it for 4 cycles to get a realistic value. On the bright side, there won't be any need to cycle the new battery once it's been assembled since the cells will have been individually tested.
I've worked out with a custom battery pack builder to make these for those of us locally here who want the extra runtime - If anyone on the list is interested in a group purchase, please let me know how many you would like so we can plan the build accordingly. Buying more cells helps get the cost down, so I can give a price after I know how many we are making.
Today, the battery is $24 cells, $1 heatshrink, $15labor, $1 tab on end for a total of $41 - which certainly does not compete with surefire's BP92! - we might be able to trim a buck a cell by buying in volume, making it $38. Remember - you'll need to have a NIMH charger to charge this pack. If there were enough 9N owners wanting to switch to NIMH, then we could get the cost down as low as 36.50!
Charger is under investigation right now as to how to buy/build/modify a Nimh charger for this pack and not go broke doing it. We have several ideas in the works, including modifying the surefire drop-in and buying a wall-mart special then doing a component change out to set it for 3.6V instead of the typical 9.6V (these are the hobby race-car type chargers specifically designed to take good care of nimh cells)
If anyone is interested - email me privately at [email protected] -- thanks!
I've worked out with a custom battery pack builder to make these for those of us locally here who want the extra runtime - If anyone on the list is interested in a group purchase, please let me know how many you would like so we can plan the build accordingly. Buying more cells helps get the cost down, so I can give a price after I know how many we are making.
Today, the battery is $24 cells, $1 heatshrink, $15labor, $1 tab on end for a total of $41 - which certainly does not compete with surefire's BP92! - we might be able to trim a buck a cell by buying in volume, making it $38. Remember - you'll need to have a NIMH charger to charge this pack. If there were enough 9N owners wanting to switch to NIMH, then we could get the cost down as low as 36.50!
Charger is under investigation right now as to how to buy/build/modify a Nimh charger for this pack and not go broke doing it. We have several ideas in the works, including modifying the surefire drop-in and buying a wall-mart special then doing a component change out to set it for 3.6V instead of the typical 9.6V (these are the hobby race-car type chargers specifically designed to take good care of nimh cells)
If anyone is interested - email me privately at [email protected] -- thanks!
