Good price for a battery?

[fishycharacter]

I just bought a used Motiv Spark. My commute is 11.3 miles. The auto route is congested and takes 30-45 minutes. No fun. The bike route is beautiful, most of it along the river, taking about 45 minutes. Great!
My battery is getting old and at the end of my ride the power is diminished. I think it is a Lithium Ion battery that has the ability for 800 cycles. My used bike may have 400-500 cycles. When I start the bike is quite peppy with a top speed of 24 mph. At the end of the commute the top speed is 16 mph. In the review they claim a range of 35 miles. I have not tried to go farther than 11 miles yet.
I would like to get an extra battery. My search has gone around and around.
The bike shop sells a battery pack for the Spark retail at $600. They say they can discount it $100. $500
There are lots of videos on building battery packs. Some using 18650 cells scavenged from laptop battery packs. Lots of work, although a challenging project and for me it would be fun.
You can purchase LiFePO4 cells in various configurations. That would reduce the work of determining capacities, but still a big project and getting expensive. 48 volt 10 Ah, 16 Headway 38120S cells $254 plus shipping.
BMS Battery sells a LiFePO4 battery pack for $259
https://bmsbattery.com/ebike-batter...k-battery.html#/335-voltage_capacity-48v_10ah
They also sell what looks like the same Lithium Ion battery that may fit the Spark for $199
(Link Removed - No Longer Exists)
LiFePO4: 2,000 cycles. Lithium Ion 800 cycles.
I'm trying to make up my mind on the best way to go.
The Litium Ion battery might fit the bike like the original but it would be tough to carry two. It would probably end up in the pack on my rear rack. Lots of weight on the rear wheel.
The LiFePO4 pack could fit in the frame forward of the main stem and just above the crank. The weight would then be distributed between the 2 wheels.
Has anyone dealt with BMS Battery?
Any opinions would be appreciated.

 

[Robert Clark]

Hi Fishy, I am getting ready to pull the trigger myself on a new battery, this company has good reviews, I'm thinking of buying from them this week. http://lunacycle.com/ I think you may find a battery that would fit your needs.

 

[fishycharacter]

I received a 52 volt 11.5 Ah battery from Luna Cycle today and rode home on it. My 48 volt bike is faster but my speedometer is on the fritz so I'm not sure how much. I also got the upgrade charger so I can charge at 3 amps to 80% for longer battery life. The old battery still has life and I can get 15 miles out of it if I go at a moderate pace. Luna got the battery out within a few days but since it is a hazardous shipment it has to be signed for on receipt. I had to have UPS redeliver it to my work place instead of home. So plan ahead.
It sure is nice having more power.
I mounted the new battery forward of the main stem so the added weight is between the wheels. The bike is listed at 49 lbs. It has added fenders, lights, a rack with a pack to make it 65 lbs. This additional battery is another 9 lbs so the bike is getting heavy.
I hope your new battery works out well for you, thanks for the response.

 

[Robert Clark]

Thanks for the report from Luna Cycle. I will get the upgraded charger, good idea not to charge to 100% to extend the life of the battery. Thanks for the tip.