Viper Submerge Battery

[rjack321]

that is true, but it is also WAY cheaper than anything from SS directly. The LiFePO4 512wh packs were $1050, and the LiPo 777wh packs were $1750. At $950 with shipping and a new charger, I think it's an infinitely better option, especially since it drops right in.
If you have a spot welder, then you're at $350ish for the cells, $100 for the BMS, and probably $20 in supplies so call it $500 to DIY, but I think $350 for someone else to take the risk/hassle of spot welding is probably worth it if you are only doing a single pack.

Yeah the OEM packs are insane. The batteryspace one is nice and I wouldnt want anyone burning down their garage, but li-ion packs are not really that hard to assemble. And the Andurino spot welders are actually cheap and easy to run. There are various commercial options to hold cells too, some even avoid needing a spot welder although they tend to take up some precious space.

 

[tbone1004]

Yeah the OEM packs are insane. The batteryspace one is nice and I wouldnt want anyone burning down their garage, but li-ion packs are not really that hard to assemble. And the Andurino spot welders are actually cheap and easy to run. There are various commercial options to hold cells too, some even avoid needing a spot welder although they tend to take up some precious space.

any recommendations on the commercial cell holders? I'm looking at converting my UV-26 and was going to do it with dewalt flexvolts, but would rather do it with individual cells from a charging hassle perspective.

 

[Caveeagle]

I had battery space spec this pack which will fit in the Viper. You will have to put your own charge/discharge connectors on there, but it will fit and is far superior to the stock pack.
Custom Li-Ion 18650 Battery: 25.45V 31.5Ah (801.6Wh, 50A rate, 7x9, INR18650 MJ1)

How does that battery compare to the 512 or 777. Ss battery?

 

[rjack321]

any recommendations on the commercial cell holders? I'm looking at converting my UV-26 and was going to do it with dewalt flexvolts, but would rather do it with individual cells from a charging hassle perspective.

I used these "hex holders" for my 7s7p Sierra battery. They worked well and I just left out a couple of cells for the bolts to connect the top and bottom plates. I managed to fit 6x7 (42 cells) in the hex holders, then there was a flat row of 7 cells and a BMS on top of them. They were budget and once you weld the cells the whole unit is totally solid. Plus the price is right
Battery kits – VRUZEND DIY Battery Kit

I used a vruzund 30amp BMS as well and I have one of their 7s 3amp chargers but I now know there are better programable chargers. 3amps is kinda slow and my cells can handle a 5amp charger easily. I got my cells from IMR on sale before the plague drove up the prices.

A couple of friends redid their old NIMH Suex batteries and made custom holders from HPDE but I don't have a table router to do that.

Ps if you want to borrow my Andurino spot welder I can loan it to you. Or you can get one assembled and ready to go from Germany (which just takes a couple months due to shipping)

 

[tbone1004]

How does that battery compare to the 512 or 777. Ss battery?

It's made out of 18650's instead of pouch cells which are vastly superior and is half the price of the 777wh version. It's not even a comparison if you need to replace it. Also of note, this will work in the UV series as well, though you'll have to figure out how to keep the battery from bouncing around.

 

[tbone1004]

@rjack321 with the SS scooters you can't use their BMS's, you need one rated for at least 40a discharge, but those kits are interesting!

 

[Caveeagle]

It's made out of 18650's instead of pouch cells which are vastly superior and is half the price of the 777wh version. It's not even a comparison if you need to replace it. Also of note, this will work in the UV series as well, though you'll have to figure out how to keep the battery from bouncing around.

thankfully, I am still getting a respectable run out of my Life20 battery.. just thinking ahead for when I will eventually need to replace it.

 

[tbone1004]

thankfully, I am still getting a respectable run out of my Life20 battery.. just thinking ahead for when I will eventually need to replace it.

they don't make the life batteries anymore, so your only option is to upgrade to lithium. They do make a 20ah lithium pack but I am unsure of the price. Either way though, to upgrade to the 30ah pack for less than a grand, you are way better off. Also to note that the SS packs only have a 30day warranty, BatterySpace is 90 days. Not significant, but it's not like you're paying for a year+ warranty to justify the extra cost.

 

[rjack321]

@rjack321 with the SS scooters you can't use their BMS's, you need one rated for at least 40a discharge, but those kits are interesting!

Gotcha yeah the Sierra only draws ~15amps and has a 30amp fuse. But I was waffling on BMS sources. While I could find various ones on ebay and alibaba etc if I was going to spend all the time and effort (~5 hours) making a battery I wanted a BMS from a "proven" source even if it ultimately was made by an unknown Chinese supplier. I figured established US companies had already figured out which BMS sources had unacceptable failure rates, so I paid a little more to get one that had a track record and presumably some vetting. So far so good, I'm happy with mine.

I don't have a reliable source for a 40amp BMS. I have used batteryspace for BMS bits before too, they are obviously legit.

 

[tbone1004]

@Caveeagle one thing to note on the BMS subject with @rjack321 . On the 20ah LiFe viper that I had and several others, the BMS was not balancing the pack properly and that was causing all sorts of issues. On my 30ah pack it was the same. I suspect BMS and charger quality were causing a lot of these failures.