18650 suggestions for small project

[steveo]

with a lot of option out there any myself mostly using a123 cells or lipo cells.. im not to shabby on which cells would be best suited for my little project. Ive only really played with the makita cells a long while back and they where great since no balance ciruit needed .. however capacity was low at only 1.5ah

so i just bought 2 neato robotic vacuums.. and i have to say they are one of the coolest toys i own. they both suffer from weak nimh batteries and the goal is to replace there oem packs with diy 18650 cells with bms to prevent overcharging and overdischarge conditions..

one neato xv-21 has 2 battery compartments which can hold max 6 18650 cells in each.. with a tiny bms.. or at least 4 cells in each.. i will use the original nimh batt sensor to trick the neato to think its battery is fully charged by placing it over the bleed resistors.. so once they are warm.. the neato will quit charging them

the second neato is a botvac 65.. for this i can either fit 6 or 9 cells to make up the battery voltage required .. i think 9 cells will be tight.. but it will be possible.. i would set it up again like i mentioned for the previous one..

so the bottom line.

the original xv 21 has 2 x 6s nimh packs to make its pack voltage 12s of nimh 3400mah or 3200 i think

the neato botvac 65 has 10 nimh cells in series to make its pack voltage .. its 3600 mah

the goal is to shove as much capacity however not to suffer to much on the discharger rate.. id prefer higher discharger rate and longer cell life and safety** and cells must be tabbed.

can anyone here recommend some cells i could use? where to buy?

i was thinking to look at some drill packs and grab cells from there like the makita 1.5ah cells.. just a thought

the neato will discharge 5amp continious.. 10 amp peak.. estimated

thanks
-steveo

 

[Wheazel]

25r cells would probably be a good option. They are among the cheaper cells as well.
I have built a trolling motor battery out of 80psc 29E cells, and a low drain fluorescent lamp battery out of 10 D1s.
Both with bms'es.

 

[steveo]

25r cells would probably be a good option. They are among the cheaper cells as well.
I have built a trolling motor battery out of 80psc 29E cells, and a low drain fluorescent lamp battery out of 10 D1s.
Both with bms'es.

thank you for your suggestion. I am considering the 25r cells.. however getting ones with tabs is a little tricky.

Being in canada, i am try to purchase local to avoid exchange.. and save some $$

I'm thinking drill batt packs//dewalt makita mawalkee b & d cells will be most feasible

-steveo