Yet another CRF 250 Build but its my first so... ;)

[DonCox]

I don't want to bad mouth Eon Lithium , but we have bought a few batteries from them, and have not been real happy. Bob knows Raymond there at EON Lithium real well, and has one of his batteries, and I put one in one of my customers bikes, and were not real keen on them. The battery you are looking at is with Samsung 50S cells, yes if you were trail riding, it would be OK, but 300A max will be weak, and if your battery is over 300A you want a QS10 Anti spark output connector. The Amorge folks can and will build to your spec. Cells are an expensive part of the equation. The video I sent you gives some pricing, but roughly the Molicel P42A, (4200mah 45AH)is about $4.50 a cell, Lishen LR2170LA(economy cell) will give you 4000mah and 35AH, but with some heat. The Samsung 50S about the same price as the Molicel P42A, but 5000mah and 45ah, but create more heat ( higher resistance). Then there are the Molicel P45B, and the P50, which are all better. P45B is what the Stark is using, and more expensive, and then the P50B which is better , but way more expensive. We have put 20S12P in the Honda frame, if you are designing for and with a quick change battery in mind this is the good size. If you could get a 20S14S or 16S battery in a CRF frame with the Molicel P45B or P50B cells you would have the range and the Power you need. You want the 40A charge BMS , but you need to have the power side Open Discharge, or no BMS control. ( to reduce heat in the battery box, since the controller has low voltage control. The battery is the most complicated part of the build.

 

[Dave Daum]

Thank you Don for all of this great information. I'll digest this and write a battery build specification for the bike I'm building.

 

[fmxxx666]

You want the 40A charge BMS , but you need to have the power side Open Discharge, or no BMS control. ( to reduce heat in the battery box, since the controller has low voltage control. The battery is the most complicated part of the build.

Hi @DonCox , do you know if its possible to ask Amorge for a 40A charge BMS and open Discharge on their batterys?

 

[DonCox]

Yes you can ask for it and they will do both. I just received a battery from them, with Open discharge, but i did not spec 40A Discharge, so it only has 20A charge. Here are a couple of pictures of the KTM battery I just got. This is a 20S12P Molicel P42A cells, Open Discharge, and Charge only Smart BMS. The Idea is to quick change out of the left side. I have to redirect the radiator bottom output to go straight up

 

[Dave Daum]

I don't want to bad mouth Eon Lithium , but we have bought a few batteries from them, and have not been real happy. Bob knows Raymond there at EON Lithium real well, and has one of his batteries, and I put one in one of my customers bikes, and were not real keen on them. The battery you are looking at is with Samsung 50S cells, yes if you were trail riding, it would be OK, but 300A max will be weak, and if your battery is over 300A you want a QS10 Anti spark output connector. The Amorge folks can and will build to your spec. Cells are an expensive part of the equation. The video I sent you gives some pricing, but roughly the Molicel P42A, (4200mah 45AH)is about $4.50 a cell, Lishen LR2170LA(economy cell) will give you 4000mah and 35AH, but with some heat. The Samsung 50S about the same price as the Molicel P42A, but 5000mah and 45ah, but create more heat ( higher resistance). Then there are the Molicel P45B, and the P50, which are all better. P45B is what the Stark is using, and more expensive, and then the P50B which is better , but way more expensive. We have put 20S12P in the Honda frame, if you are designing for and with a quick change battery in mind this is the good size. If you could get a 20S14S or 16S battery in a CRF frame with the Molicel P45B or P50B cells you would have the range and the Power you need. You want the 40A charge BMS , but you need to have the power side Open Discharge, or no BMS control. ( to reduce heat in the battery box, since the controller has low voltage control. The battery is the most complicated part of the build.

Thank you Don for all the wonderful information. Now I have to figure out how to get the most power and range into the fairly small space I have to work with. It is going to take some creative fabrication. Looks like I'll need to reduce the size of the shock tower cross member and the wishbone. Trying to get a 6.25 x 8.25 x 13.00 battery case in this s.all space is challenging. Hoping to get 20S 12p.

 

[bananu7]

I hope you weld in some reinforcements if you cut out as much as you're drawing here.

 

[Dave Daum]

The plan is to remove as little material as possible. Once the battery arrives I'll carefully fit it to the bike. I want to avoid welding on the aluminum chassis. My fear is the welding will change the heat treatment and soften the aluminum.

 

[fmxxx666]

Trying to get a 6.25 x 8.25 x 13.00 battery case in this s.all space is challenging.

this sizes sound exactly like the Electro & Co eg. eonlithium.com 76v 48ah battery.
Also tried to test fit that in the 2009 CRF 250 Frame but zero chance would have to cut away way too much from the frame.
so 72v will be enough for me I will see what amorge is able to do maybe also an "irregular shape batt" they have done these before:





something like this so it goes down in front of the Motor and uses that space as well:

 

[DonCox]

I have a 6.25x8.25x13" Amorge in a 2005 450CRF frame with only slight mods. I heard that the 250 frame is narrower