52V downtube packs: EM3EV 35E vs Electron 21700 vs other?

[Peddlin' Pedro]

Got a 52V BBSHD on the way but yet to order a battery pack. Would appreciate first hand insight on two packs I've shortlisted, or recommendations for alternatives of comparable spec and quality from UK sellers which are in stock. Must be lockable downtube styles as has to be removed from bike for charging. The two I've been looking at are:

EM3EV (via Eclipse Bikes) 52V 17Ah, Samsung 35E, Jumbo Shark - HERE
Pros: exceptional build quality, reliability, safety, serviceability and insight via smart BMS
Cons: 35Es maybe not ideal for higher demand use (towing), slightly reduced range when compared to...

Electron Cycles' 52V 19.5Ah, Panasonic 21700, Polly - HERE
Pros: capacity and range, cell spec possibly better suited to use case
Cons: build quality unknown, lack of smart BMS, whiff of excessive marketing BS makes me wonder if it's any different to identically specced (on paper) packs available elsewhere (said as a marketer of 20+ years)

First hand experiences, thoughts or suggestions appreciated. Thanks!

 

[wheeliepete]

I would go with EM3EV pack for build quality every time, but as you say 35E's not ideal for running at 6 amps for extended periods. The PF cell would be more suitable, but obviously reduced range. Having seen inside an Electron pack, they are not built anywhere near as well. Might be worth enquiring about the specs of this one, going by the capacity, it must be built with 21700 cells.

52V 19Ah Downtube eBike Battery

A higher capacity 48v battery with good quality cells. Our best selling battery will last you for a long time, and comes with a 12month warranty. Charger included.

custombuilt-ebikes.co.uk

 

[Fordulike]

I would have to agree with wheeliepete, the EM3EV pack is impecably built. I've got the 48v 15Ah version with LG HG2 cells. The bluetooth BMS is a nice feature to check on charging, discharging, cell condition etc.

As you say, the 35E's may not be ideal for repeated high current demand (they'll take it, but possibly shorten battery lifespan), but you can always tweak down the max current, by using a programming cable. 30 amps from a controller on a mid drive is probably overkill as it is.

Your drivetrain will thank you, by knocking max current down to the 20-25 amp range. Believe me, it'll still haul arse like a beast, the joys of running the power through gears.

 

[Peddlin' Pedro]

I would go with EM3EV pack for build quality every time, but as you say 35E's not ideal for running at 6 amps for extended periods. The PF cell would be more suitable, but obviously reduced range. Having seen inside an Electron pack, they are not built anywhere near as well. Might be worth enquiring about the specs of this one, going by the capacity, it must be built with 21700 cells.

52V 19Ah Downtube eBike Battery

A higher capacity 48v battery with good quality cells. Our best selling battery will last you for a long time, and comes with a 12month warranty. Charger included.

custombuilt-ebikes.co.uk

Thanks for that. Just called, and while they were very nice and did their best to help I got the impression they'd no idea what's inside it. They did send the pic below, which shows Samsung 33G cells. This older thread suggests a revision to cell chemistry was pending but no idea what version is in this pack, or how it's been put together.

Regarding the Electron pack: when you say '...not anywhere near as well built', is that to a concerning degree or is it acceptable when compared to anything other than EM3EV or the packs from Insat/Jimmy?

 

[Peddlin' Pedro]

I would have to agree with wheeliepete, the EM3EV pack is impecably built. I've got the 48v 15Ah version with LG HG2 cells. The bluetooth BMS is a nice feature to check on charging, discharging, cell condition etc.

As you say, the 35E's may not be ideal for repeated high current demand (they'll take it, but possibly shorten battery lifespan), but you can always tweak down the max current, by using a programming cable. 30 amps from a controller on a mid drive is probably overkill as it is.

Your drivetrain will thank you, by knocking max current down to the 20-25 amp range. Believe me, it'll still haul arse like a beast, the joys of running the power through gears.

Helpful, thank you. And yes, had absolutely planned to dial it back in settings; programming cable arrived this morning, just waiting for the drive. I've no interest at all in monster power or quarterly drivetrain swaps so was thinking 20A max. Want to run it as lean and cool as I can.

EM3EV sent a comprehensive reply to my enquiry about plans for larger packs/cells, and suggested there may be a larger celled pack coming within the next month or two. The chap at Eclipse bikes was also very open about the relative merits of respective packs/cells, which inspires some confidence regarding the UK after sales support.

 

[wheeliepete]

Thanks for that. Just called, and while they were very nice and did their best to help I got the impression they'd no idea what's inside it. They did send the pic below, which shows Samsung 33G cells. This older thread suggests a revision to cell chemistry was pending but no idea what version is in this pack, or how it's been put together.

Regarding the Electron pack: when you say '...not anywhere near as well built', is that to a concerning degree or is it acceptable when compared to anything other than EM3EV or the packs from Insat/Jimmy?

Shame Custom Ebikes weren't more helpful, they're a newish company about 3 miles from me, but poor product knowledge is never very reassuring.
I can only comment on the 2 packs I had from Electron, both bought cheaply with defective BMS's. The cells were Chinese made Sanyo GA's which were glued together and the connectors on the cells were nickel plated steel, which isn't ideal for high power use. Their present stock may well be completely different, so i'm not slating them, they have hopefully learnt their lesson and I get the impression they offer good CS should you have any problems.
At least we now have a few UK sellers of battery packs which did not exist 2 or 3 years ago and they are all on a massive learning curve that companies like EM3EV went though 15 years or more ago.

 

[peter.c]

The 2 most recent packs used have been a 52v 19.2 with 5a charger from hallomotor [£330] arrived in 10 days the power from the hd was extreme/ frantic over 1500-1700 watts on the display more on a fresh battery, far more torque than the tsdz2 you are used too. Probably more on level 1or2 than the tsdz in turbo mode if you ever need high assist the speed would be very fast. The gearing/speed to power is important as the drive train gets a hard life
As for the range played all day on lower/ mid power got a couple of hours ridden hard
The most recent from risunmotor DE 48v 19,2 also £330 arrived in under a week posted from the uk sent DHL [check if they have stock here first] also tried on the hd less power 1200-1500 watts but nicer power delivery and less harsh on the chain did not try the range
After my trials ended up selling the fs bike far to bulky/heavy with the HD [the balance lifting it over a gate] now gone back to bbbs02 and 48v 19.2 get two days fun on one charge only notice the slight power difference so re geared with a 36t front lekkie
Both packs sold as 21700 Panasonic cells not opened to check

 

[Peddlin' Pedro]

Shame Custom Ebikes weren't more helpful, they're a newish company about 3 miles from me, but poor product knowledge is never very reassuring.

Very best of luck to them. She was definitely trying her best to help so can't fault them on that. As you say though, stronger product knowledge would be good, and I'm not willing to take a chance on an unknown.

I can only comment on the 2 packs I had from Electron, both bought cheaply with defective BMS's. The cells were Chinese made Sanyo GA's which were glued together and the connectors on the cells were nickel plated steel, which isn't ideal for high power use. Their present stock may well be completely different, so i'm not slating them, they have hopefully learnt their lesson and I get the impression they offer good CS should you have any problems.

I may ask Electron Cycles if they've any internal pics of their current packs but the EM3EV is leading at present.

At least we now have a few UK sellers of battery packs which did not exist 2 or 3 years ago and they are all on a massive learning curve that companies like EM3EV went though 15 years or more ago.

Nice to see the market developing isn't it. I actually approached Insat/Ebike Batteries first but they're not expecting any cases for a few weeks, so delivery of a completed pack would likely be to far out for my needs.

 

[wheeliepete]

Just had a look at the offerings from Electron, it does look like they have upped their game and improved the spec. of their batteries. If your budget allows and it fits your frame, this is the battery to power an HD motor for as long as you like.

52V Battery 34Ah, 6A Charger | Electron Cycles

Colossus 2, 52V, Triangle Battery. 70A, 34Ah 1768Wh Bluetooth, 5A Charger

www.electroncycles.co.uk

It's true that power delivery is not great with the standard HD controller, esp. on throttle, but please don't turn your motor down to 20 amps, it won't thank you, it's a beast that will run at full power all day without breaking a sweat and your gonna need it with the loads you're carrying.

 

[Peddlin' Pedro]

Just had a look at the offerings from Electron, it does look like they have upped their game and improved the spec. of their batteries. If your budget allows and it fits your frame, this is the battery to power an HD motor for as long as you like.

52V Battery 34Ah, 6A Charger | Electron Cycles

Colossus 2, 52V, Triangle Battery. 70A, 34Ah 1768Wh Bluetooth, 5A Charger

www.electroncycles.co.uk

I was tempted by that pack and think it may just fit in the frame (Yuba Mundo with quite a compact triangle) but due to both access to power and temperatures in the bike shed I have to remove the pack for charging. Shame, as otherwise I'd fix it into the frame with hose clamps and never have to worry about range again.

It's true that power delivery is not great with the standard HD controller, esp. on throttle, but please don't turn your motor down to 20 amps, it won't thank you, it's a beast that will run at full power all day without breaking a sweat and your gonna need it with the loads you're carrying.

Never having setup a BBSHD or run one on a heavy cargo bike before I've no idea what settings/current are likely to work best, so 20A was only ever a finger-in-the-air starting point. Main objectives are to optimise range, progressive power delivery, climbing performance when towing and reliability/longevity of battery, powerplant and drivetrain. I'm geared for climbing (42f/40r) so not putting massive torque through the drivetrain and it spins out at 22mph downhill so there won't be any speed records. Keeping the speed down is important with a gross weight of ~250kg as you've still got to stop it safely, hence 4-pot calipers, big rotors and durable tyres.

 

[Peddlin' Pedro]

Went with the EM3EV from Eclipse Bikes. Taking a slight hit on range but should be sufficient for my needs if I drop the current slightly. Said as if I know what I'm talking about but I've never tweaked the settings in a BBS, but am assured it's doable and that I can achieve a happy medium of pulling power and efficiency.

Main reasons for the choice were the known build quality and cell supply (no chance of re-wraps/ringers), the warranty and availability of a quick-swap BMS replacement that doesn't require return to Eclipse in the event of a failure. Rob's willingness to discuss my use and the fact that he just comes across as a decent bloke also helped.

When EM3EV do release a larger capacity pack I may look at one of those too.

Anyone got any recommendations for a sensibly priced 52V 4-5A charger that can be set to 90%?

 

[Nealh]

It's not a charger you really need for 90%, ideally you need a BT or Uart BMS which then can have the balance correctly set to 90%. Then you know for sure the cells will be looked after correctly and can check cell balance when ever you like.

 

[Peddlin' Pedro]

It's not a charger you really need for 90%, ideally you need a BT or Uart BMS which then can have the balance correctly set to 90%. Then you know for sure the cells will be looked after correctly and can check cell balance when ever you like.

The pack has a bluetooth BMS and will balance at >50% charge. Was thinking more about longer term cell health and not having to check the BMS to see when it hits 90%.

 

[wheeliepete]

I've had one of these for 3 years with no problem. You can trim the voltage down to 57.4v with the pot inside. Also in 5,6,7 amp versions.

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[Nealh]

The pack has a bluetooth BMS and will balance at >50% charge. Was thinking more about longer term cell health and not having to check the BMS to see when it hits 90%.

Use a standard voltage charger then, set the BT BMS to 90%/ 4.1v per cell balance. Once the 90% balance charge is reached the BMS will switch off the current and the chargers light will go from Red to Green as normal.

 

[doctoral]

I have played around with both adjustable chargers and bluetooth bms. The basic (bigger than 2A) china charger with the aluminium housing and fan is easy to open up and turn down the voltage, works well with a non BT BMS. The BT bms is a bit fiddly to regulate the final charge voltage, I found it easier to tune the charger. Finally, the Meanwell chargers are a step up from the the usual ebike charger, with externally adjustable current and voltage, long warranty and excellent build quality. They are much more solidly built and the fan only runs when needed.. Imagine the efficiency is higher also. NPB360 is the one I have.