21700 10 Ah Battery Build: Peer Review

[Solarbake]

update to the battery pack tried with a watt meter max current draw was 15.5 amps and 550watt draw on the watt meter .On my 19 mile each way commute 5.9 amp/hr was consumed each way from the 10 a/h pack.The battery was Luke warm to the touch so happy with that ,

The 50e are rated at 10 amp max so at 2p configuration 20 amp is maximum and I was drawing 15.5amps for short bursts so the Next pack will be 10s3p to reduce the max draw in each cell when fogstar get them back in stock

 

[rig the jig]

This is my new 21700 battery built for my swytch gen 3 which I tapped into the speed controller so any 36V Battery can be utilized .
I used the samsung 50 E from fogstar in a 10s2p Format. Whole pack cost me less than a £100.
The powers great and so is the range.They are rated at 10A discharge .Heres a few pic of my pack.
Fogstar by the way are great genuine cells and next day delivery just make sure you buy from the wholesale website.Also I can run on two Makita LXT 5amp/h battery's if I want with the adpater

Hi I have a swytch Gen 2 ( the one without display), and I'm looking for someone to quote me for a 10A quality rebuild, anyone interested?

 

[saneagle]

Hi I have a swytch Gen 2 ( the one without display), and I'm looking for someone to quote me for a 10A quality rebuild, anyone interested?

You can use any 36v battery with a Swytch kit. You don't need to go to the expense of a rebuild. If you want one to go in the bag, there are loads of brick shaped batteries on Aliexpress, but I'd fit a proper downtube battery or a rack battery. It's just two wires from the battery to the controller that sits in the bag. Unclip the old ones and clip in the new.

 

[Cisco-man]

This is my new 21700 battery built for my swytch gen 3 which I tapped into the speed controller so any 36V Battery can be utilized .
I used the samsung 50 E from fogstar in a 10s2p Format. Whole pack cost me less than a £100.
The powers great and so is the range.They are rated at 10A discharge .Heres a few pic of my pack.
Fogstar by the way are great genuine cells and next day delivery just make sure you buy from the wholesale website.Also I can run on two Makita LXT 5amp/h battery's if I want with the adpater

Hi Solarbake. You’ve done exactly what I want to do - connect two of my Makita batteries in series. I’d appreciate any detail as to how you connected these into the battery holder.

 

[Solarbake]

Hi Solarbake. You’ve done exactly what I want to do - connect two of my Makita batteries in series. I’d appreciate any detail as to how you connected these into the battery holder.

Just bought two holders off eBay and wire them in series and mounted them on a perpex sheet pic attached

 

[Cisco-man]

Just bought two holders off eBay and wire them in series and mounted them on a perpex sheet pic attached

Thanks. Sorry, didn’t make what I needed clear! I’ve got the Makita battery holders which I’ll connect up in series. I’m also going to add a 10A voltage regulator to bring the voltage down to 32v before it goes into the Swytch battery holder on the handlebars (the Max battery appears to do that too). What I‘d like to know is what connections you made inside this Swytch battery holder on the handlebars.

 

[Nealh]

A new thread with an appropriate title should be started instead of hijacking someone elses thread, then in the future it may be easier for others to find.

 

[saneagle]

I’m also going to add a 10A voltage regulator to bring the voltage down to 32v before it goes into the Swytch battery holder on the handlebars (the Max battery appears to do that too).

There's no logical reason Swytch would do that. Before doing anything stupid, you should open up your controller box and look inside. The last pictures showed only two wires to the battery connector, but for some reason, the guy wouldn't show pictures that were definitive.

 

[Cisco-man]

I’ve been told to start a new thread on this, which I will. If you measure the charge connector in the middle you get full battery voltage (around 42v). If you measure at the output slots you get 32v. When the battery declares that it’s flat, the battery is 32.6v. I Accept that my crude analysis of this may well be wrong, but in my experience as a humble electronics engineer I would feel that there is a power transistor circuit in the battery housing taking it down to 32v in order to keep the feed at this voltage, and the 0.6v is the voltage drop across the semiconductor junction.

 

[saneagle]

I’ve been told to start a new thread on this, which I will. If you measure the charge connector in the middle you get full battery voltage (around 42v). If you measure at the output slots you get 32v. When the battery declares that it’s flat, the battery is 32.6v. I Accept that my crude analysis of this may well be wrong, but in my experience as a humble electronics engineer I would feel that there is a power transistor circuit in the battery housing taking it down to 32v in order to keep the feed at this voltage, and the 0.6v is the voltage drop across the semiconductor junction.

You have a very vivid imagination. You should be a story write in the film industry. Wouldn't it be a good idea simply to look in the box and see what's actually there?

 

[Solarbake]

The Swytch needs needs 36v or more no need to drop it done you would get reduced power output.The oled controller shows battery voltage of 41.5 on fully charged battery anyway.