3rd Gen Swytch MAX Battery lights

[Chewybacher]

I've used my new Swytch kit twice now (knock on wood, no real problems...yet!). However, I found out today that the indicator lights on my MAX battery don't give you an accurate view/reading as to how much charge you actually have. My battery dropped from full to one in about a half hour of riding this morning, (I did use it last week on a 14 mile ride and didn't charge it afterwards because the all of the lights were still lit, as if it was still fully charged).

It kept bouncing from 1 to 2 lights 30 minutes into my ride, and the kit switched off with only one light illuminated on the MAX battery.

Has anyone else experienced this?

BTW, I have the LED display (which is sufficient for me needs).

 

[Branox]

I've used my new Swytch kit twice now (knock on wood, no real problems...yet!). However, I found out today that the indicator lights on my MAX battery don't give you an accurate view/reading as to how much charge you actually have. My battery dropped from full to one in about a half hour of riding this morning, (I did use it last week on a 14 mile ride and didn't charge it afterwards because the all of the lights were still lit, as if it was still fully charged).

It kept bouncing from 1 to 2 lights 30 minutes into my ride, and the kit switched off with only one light illuminated on the MAX battery.

Has anyone else experienced this?

BTW, I have the LED display (which is sufficient for me needs).

I also have the MAX battery with LED display. A similar thing is happening with mine, except it does the bounce between 2 and 3 lights when the power drops out. When the power first drops, the battery shows 3 green lights and the LED display/control unit shows 1 blinking red light. After the first power drop, I'll get intermittent power for a few more miles where the battery LED bounces between 2 and 3 lights. After those few miles, the power quits completely and I'll usually end with 3 green lights on the battery. Swytch has replaced both the battery and the LED display/control unit, and I have the identical problem with the replacements. I'm averaging about 10mile range on the medium assist setting.

 

[Benjahmin]

The led indicators do not indicate how much charge is left in the battery.
They are voltage indicators.
When a heavy draw is required of the battery voltage will decrease then recover when the draw/load is removed.
Small Ah (Amp Hour) batteries will suffer more from this. Also the current rating of the battery relevent to the current rating of the controller, is important.
i.e. If the battery is rated at, say, 10A, but the controller calls for 12A, then the battery is not able to supply this and voltage will drop quickly.
I don't know what size batteries Swytch supply nor their capacity. I believe they are small.
I don't know what rating their controller is. However what is being described here sounds very much like voltage sag caused by a battery/controller mismatch, or poor batteries.

 

[saneagle]

I also have the MAX battery with LED display. A similar thing is happening with mine, except it does the bounce between 2 and 3 lights when the power drops out. When the power first drops, the battery shows 3 green lights and the LED display/control unit shows 1 blinking red light. After the first power drop, I'll get intermittent power for a few more miles where the battery LED bounces between 2 and 3 lights. After those few miles, the power quits completely and I'll usually end with 3 green lights on the battery. Swytch has replaced both the battery and the LED display/control unit, and I have the identical problem with the replacements. I'm averaging about 10mile range on the medium assist setting.

The lights are basically a poor voltmeter. The voltage bounces up and down a lot when you have a small battery and take a lot of power from it. You cannot help that.

 

[Branox]

The led indicators do not indicate how much charge is left in the battery.
They are voltage indicators.
When a heavy draw is required of the battery voltage will decrease then recover when the draw/load is removed.
Small Ah (Amp Hour) batteries will suffer more from this. Also the current rating of the battery relevent to the current rating of the controller, is important.
i.e. If the battery is rated at, say, 10A, but the controller calls for 12A, then the battery is not able to supply this and voltage will drop quickly.
I don't know what size batteries Swytch supply nor their capacity. I believe they are small.
I don't know what rating their controller is. However what is being described here sounds very much like voltage sag caused by a battery/controller mismatch, or poor batteries.

The product manual (https://www.swytchbike.com/manual.pdf, page 45) indicates that the battery led light represents the battery capacity.

 

[cyclebuddy]

The product manual (https://www.swytchbike.com/manual.pdf, page 45) indicates that the battery led light represents the battery capacity.

Page 45 doesn't actually say it's showing battery capacity (see clip 12 from P45 below). As others have already said, the LED's indicate battery percentage (that's what the manual actually says): They're measuring/showing voltage. When fully charged, the voltage will be around 41/ 42v, and when empty, around 30/32v. That's what is being shown. Heavy drain (using full assist, going up hills etc) will cause the voltage to sag... very much so given the very small 90Wh or 180Wh battery capacity compared to other e-bikes/kits.

 

[Benjahmin]

As others have confirmed, the leds are live voltage indicators. They show the battery voltage instaneously.
Even if you have the 'large' 180Wh battery, that is only a very small 5Ah. Not good for much more than a bit of shopping round town - if it's fairly flat.
Any heavy draw on such a small battery (high assist hill climbing or prolonged high assist speed) will cause voltage sag, which is what your original post seems to indicate.
If the voltage bounces down far enough, the system cuts off. This is the low voltage cut off (lvc)coming into play to protect the battery from damage. While it's off the battery chemistry allows the voltage to recover so the system can be switched back on. However it will sag to cut off sooner now as the voltage is already low.
This is life with a small battery I'm afraid and is why there are a few threads on the forum where people are trying to add bigger batteries to their Swytch kits.

 

[bikeymikey]

i have exactly the same problem, once the battery drops to 3 lights it continually cuts out, thinking about returning it tbh it seems very underpowered

 

[Solarbake]

i have exactly the same problem, once the battery drops to 3 lights it continually cuts out, thinking about returning it tbh it seems very underpowered

I’m running mine on 2 x makita lxt batteries works great

 

[bikeymikey]

I’m running mine on 2 x makita lxt batteries works great

seriously? how have you got it wired up? ir even attached 2 ur bike?

 

[Solarbake]

Battery in bag at moment on front extra connector going into speed control

 

[bikeymikey]

Battery in bag at moment on front extra connector going into speed control

that’s absolutely brilliant, thanks for putting up the photos, the wiring looks pretty straight forward into the controller. what about recharging? I guess you’d use the makita recharger…

 

[Solarbake]

Yes I use the makita charger for the two lxt battery's also making a couple of packs from a broken Xiaomi scooter which is 7.6a/h
and a broken bosch power pack 400 11a/h so should have plenty of range .

 

[heythisisdave]

Hey @Solarbake do you still use the normal Swytch batteries? Did you splice that xt60 connector or just replace it?

I also get range anxiety with the MAX on two 6 mile commutes - by the end of the second commute it's cutting in/out constantly.

 

[Solarbake]

Hi I took the controller apart few screws to undo and soldered in a new lead .I changed to anti spark XT60
on the batterys as was getting a few sparks connecting my packs up.I made a cople of packs ranging from 8amp/hr to 18amp/hr and just leave them in a brompton bag on the front.

 

[heythisisdave]

Hi I took the controller apart few screws to undo and soldered in a new lead .I changed to anti spark XT60
on the batterys as was getting a few sparks connecting my packs up.I made a cople of packs ranging from 8amp/hr to 18amp/hr and just leave them in a brompton bag on the front.

Did you splice it in to the current wire or replace the wire to the controller board itself? Do you still use the Swytch batteries at all or just the new packs?

Thanks!

 

[Solarbake]

Spliced into existing wires so can use swytch battery or my own

 

[Cisco-man]

I use four Makita batteries on my Swytch Max setup. four are good for up to 20 miles of moderate assistance. Not worth doing unless you already have the batteries because a 36v decent battery pack is a lot cheaper than using Makitas. Makita batteries also are highly protected by the onboard BMS - which stops you charging the packs to their full potential.