Tdi li-ion battery pack build

[labradigger1]

My trusty tdi (big box) battery pack is finally going bad. It is at least 10 years old.
I was thinking of building a new one. The whites pack has Samsung 18650 2200ma batteries (x8) now.
Does anyone know if it would be feasible to use EBL 18650 3000ma batteries in this build?
Would the additional 800ma per battery make the pack discharge slower equaling longer run times?
Thanks.

 

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[Jim in Idaho]

Yes...you can do that, and it will increase the runtime. If you use 3 cells, you'll get a max of 12.6v, and an average of 11.1v, which is the nominal voltage of a 3 cell setup. You may need to gut the factory pack to have room for the 18650's as they are a bit thick at 18mm. If you take everything out of the pack, except the factory contacts where it mates with the circuit board, you can use 4 of the 18650's, and there's still room for a balancing, or protection board. That's what Reidman offers with his pack, which is for sale on Ebay. That pack gives you an average of 14.8 volts, and max of 16.8. The extra voltage makes a definite increase in depth and sensitivity with the 12"DF coil, and other larger coils. Not a big improvement on the smaller coils. You can find his pack here:https://www.ebay.com/itm/Whites-TDI...586564?hash=item33e08bbdc4:g:HfMAAOSws5Baah8g

 

[labradigger1]

Yes...you can do that, and it will increase the runtime. If you use 3 cells, you'll get a max of 12.6v, and an average of 11.1v, which is the nominal voltage of a 3 cell setup. You may need to gut the factory pack to have room for the 18650's as they are a bit thick at 18mm. If you take everything out of the pack, except the factory contacts where it mates with the circuit board, you can use 4 of the 18650's, and there's still room for a balancing, or protection board. That's what Reidman offers with his pack, which is for sale on Ebay. That pack gives you an average of 14.8 volts, and max of 16.8. The extra voltage makes a definite increase in depth and sensitivity with the 12"DF coil, and other larger coils. Not a big improvement on the smaller coils. You can find his pack here:https://www.ebay.com/itm/Whites-TDI...586564?hash=item33e08bbdc4:g:HfMAAOSws5Baah8g

Why only 4 batteries? The whites pack I have now is 8 18650 batteries now. It also has the pcm board.

 

[Jim in Idaho]

I goofed...was thinking of the TDI SL. I've never heard of an 8 battery TDI pack...at least not the Li-ion 18650's. I thought the TDI used a 5 cell pack. Are you sure the pack uses 8 18650 rechargeables?
Jim

 

[labradigger1]

Now I see your confusion. Yes, this is an original tdi, pre tdi pro. Yes it has an 8 cell Samsung 18650 22f battery pack. I have it torn apart now.

 

[Jim in Idaho]

What I don't get is the li-ion cells are 3.7volts. The original TDI's ran on 18.5 volts. That's 5 cells. I don't understand what the additional 3 cells do, or how they could be configured to give more runtime. Two sets of four would double the runtime, but only give 14.8 volts.
Kind weird. Are those cells the same size as AA's?
Jim

 

[Jim in Idaho]

I figured it out....they ran on 14.8volts. The 8 cells doubled the runtime. You have 2 4-cell packs wired in parallel. You can run them on voltages up to 18.5 nominal, or 21v fully charged, but there isn't room in the pack for 10 cells, so you use 5 cells in series, instead of 4. You'd get additional depth with the large coils, but you'd cut your runtime in half. I use a Reidman pack in my SL to boost the depth. I get about 6 hours out of a charge. He uses 3400mah 18650's. I think he also makes packs for the TDI's and Pros.
Jim

 

[Jim in Idaho]

I just checked his listings on EBay, and he no longer lists the TDI packs.
Jim