Just received a new Dorado 25ah battery

[tomjasz]

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em3ev.com

 

[Bitmugger]

EM3ev doesn't seem to even sell a Dorado compatible battery?
No argument with EM3ev being a supplier you trust, but Jenny and Aujiu's batteries are used in 1000's and 1000's of ebikes, scooters, etc. Selling direct to users is a side business for them, they sell wholesale to bike and scooter companies mainly. I have a lot of confidence in them and Jenny is fantastic to deal with.

 

[tomjasz]

EM3ev doesn't seem to even sell a Dorado compatible battery?
No argument with EM3ev being a supplier you trust, but Jenny and Aujiu's batteries are used in 1000's and 1000's of ebikes, scooters, etc. Selling direct to users is a side business for them, they sell wholesale to bike and scooter companies mainly. I have a lot of confidence in them and Jenny is fantastic to deal with.

Jenny and Aujiu's batteries are used in 1000's and 1000's of ebikes, scooters, etc.

I'm sorry, but I don't buy the claim. BTW I do have a battery from her. It lacks the sophistication other makers sell. It's performing well.

My former shop lost THOUSANDS on a payment scam. Leaving me with a loss of trust. Let me ask you this: if a seller does thousands of builds, why bother to sell here?

 

[Woiz]

Hi Bitmugger

Thank you for your reviews, I‘m interested in purchasing one for myself. But I‘m wondering about waterproofing. I ride all year, even in heavy rain, and up to an hour per ride. So the battery is exposed to quite a lot of moisture. I now have a dorado max battery from frey bike and it holds up well. I opened it up recently and after almost 4 years of use, there was some minor corrosion on the plug, connecting the battery pack to the power outlet.

Can you say anything about your batteries? Have you used them in rain too? Are they probably comparable?

Thanks and cheers

 

[Bitmugger]

My son rides all year winter (snow) and summer. He has some Aujiu's batteries and they've served him well. We haven't opened them up though. I have opened my battery the 25ah and it has seals and such as was fine inside, We've biked 2 Aujiu's batteries in a hurricane once as we were on a multi-day trip and got caught needing to make a ferry while the hurricane was on us. I've also ridden in the wet many time but rarely set out in the rain, just get caught in the rain. That's about the best I can offer for experience.

 

[6zfshdb]

I have two older style Dorado DP9 52V, 20ah batteries that get used in the rain occasionally. The DP9 case isn't waterproof but I've never had a problem with corrosion in the past. If there's rain in the forecast, I stretch an old shower cap over the battery or apply plastic wrap around the downtube and battery. I can still operate the switch and see the charge level gauge through the clear plastic.

 

[-sandro-]

are batteries from @Jenny Mao still available and safe?
Or which alternative for Europe?

 

[Bitmugger]

are batteries from @Jenny Mao still available and safe?
Or which alternative for Europe?

I can confirm my battery from Jenny continues to work after years of use and 1000's of km. I have other batteries from her that also work great. I've come to count Jenny as a friend of mine and she's been fantastic. Unfortunately she has taken another job and no longer works for Aijiu Energy but you can contact them through Alibaba to arrange a battery. I believe in recent years they switched from Samsung cells to a Chinese manufacturer that Jenny said she had faith in but I believe you could request Samsung for an extra fee.

In my opinion based on the construction of the battery packs that fire should not be a special concern, they were double wrapped internally with a good BMS.

Here is an Alibaba link to them

https://www.alibaba.com/product-detail/Reention-21700-Dorado-Ebike-Battery-36V_1601763467840.html?spm=a2700.shop_plgr.41413.5.70fa4e73hgEnhr

 

[-sandro-]

Ok thanks, I don't think I'm gonna risk it. However who says those selling from EU companies aren't just reselling these batteries and putting fake certifications on them?

 

[Bitmugger]

Ok thanks, I don't think I'm gonna risk it. However who says those selling from EU companies aren't just reselling these batteries and putting fake certifications on them?

Totally your call on where to purchase. Aijiu is a company I trust to be honest and deliver what they promise. Via Jenny, myself and others have purchased dozens and dozens of batteries through Aijiu. Jenny only moved on due to having a 2nd child and quitting the job to be a mom a while before going back to work. I was fortunate being the 1st client for the 25ah battery to see pics of the construction of my battery and various engineering reports and tests but that's not typical.

My worry with any vendor is:
1) Are the cells inside good quality and accurately rated for capacity and chemistry
2) Did they use good internal connectors and welds on the cells
3) Did they use a good BMS
4) Are the cells wrapped properly so they won't allow contact from the cells to any metal on the shell

I know Aijiu was supplying batteries to numerous e-bike makers but that also means those e-bike makers could well be switching suppliers to who ever is cheapest at that time. It's a real guessing game.

 

[tomjasz]

I'm disappointed. It's a nearly average build. Absolutely featureless BMS.
The best of the 6 makers we worked with and sold was EM3ev. Unbeatable quality but somewhat limited choices. Reention cases, Bluetooth BMS, fused cells, and more.
An Irish expat's factory in China.

We finally did it, it wasn’t easy, but we finally developed a Compact 36V Shark Battery with 40pcs of 2170/21700 cells. This a big step forward in every way from the original EM3ev 18650 shark batteries. Using the knowledge and experience we have gained over the years, we have made an even safer battery, with better energy density, with better fusible nickel terminations and an interconnect PCB (with fusing). We also created a new, smarter BMS, with great logging capabilities, with high current, that fits in a tiny footprint.​

So why is the EM3ev King Shark, King and why is the latest Shark Family from EM3ev a cut above the rest?​

This is why:​

• We assemble ALL our batteries in our factory, using custom parts we design and then manufacture on our own CNC machines. We don’t buy from Battery Pack Assemblers that sell at the lowest price to attract buyers, but then have to scrimp on everything, then assemble them as quickly/cheaply as possible, so they turn a profit. We don’t take chances when it comes to our batteries or your safety!
• We only source genuine A-grade genuine cells from the official sources.
• The EM3ev King Shark case is built and designed for 56 cells (the case itself is bought in from our preferred case maker). We were not willing to sacrifice safety and reliability by squeezing 56 cells into the Hailong case, that was only ever intended for a max of 52 cells, which is why we waited until a suitable case was available, before we offered our 52V EM3ev Shark batteries. The only way it was possible for others to offer a 52V battery in the Hailong case, was to discard the standard cell holders and glue the cells together.
• Our EM3ev King Shark uses an in-house designed and manufactured CNC cell holder which keeps everything safe, solid and secure. The quality and construction of the injection moulded case is also (in our opinion) far superior and the slider mountings are on a totally other level to the Hailong. The slider is solidly constructed and even has fixing points that match most water bottle mounts. No drilling holes or adding additional brackets to make it work!
• Every cell in the pack is fused (just like almost all of the batteries we supply). We have been designing and manufacturing (in-house) our own battery terminations for several years already. Cell level fusing, means that in the event of an internal short circuit in the battery (which the BMS cannot protect against), then all that will happen is that some sacrificial links will safely open, preventing any of the cells or cabling from overheating and becoming dangerous. CNC spot welding ensures consistent weld quality and weld position. Finally, our new PCB design offers better internal cable management and routing. Safe by design!
• We use a high tech, fully programmable UL-certified Smart BMS, which is rated for genuine 40A continuous plus, with a programmable over-current trip set to >60A (which is ample for the intended application). Our BMS balances during charging (when charging and when at >50% charge) and therefore doesn’t require a full charge in order to balance. Auto power off function, auto power on and with a pre-charge function (no sparks, so long as the battery is powered off when linked to the controller).
• This is a 3-wire BMS with separate charge and discharge circuits. The charge port doesn’t not output the battery voltage and will avoid sparking if you forget to power on your charger prior to connecting it. Like all our batteries, the King Shark supports regen.
• We do have a battery parallel balancing device called a dual battery balancer that can be used for running two batteries in parallel under all edge cases. The battery parallel balancing device works from 10S (36V) to 14S (52V). As long as the voltages of the two batteries are the same – eg. both are 14S etc. it will work with all cell types and capacities. The dual battery balancer has a max discharge current of 60A and regen is not permitted. Please contact us if you are interested in this device.
• High current charge plug comes as standard (approx. 8A rated). We don’t use the standard DC2.1 connector (fitted to most of this style of case), that is only rated for 3A and is likely to melt at much more than that.
• We do all this and offer it at our usual low pricing, we don’t charge a premium for Safety and Reliability. Just because we offer low prices, it doesn’t mean we don’t stand behind our product if there is an issue. We have a proven track record of offering great after-sales support and warranty repairs/replacements. We will not leave you stuck (1 year Warranty, with several Support Centres World-Wide). Our batteries are designed to be easily repaired if the need arises.

Features of EM3ev King Shark Case:​

• The controller case in the slider (that most do not even use) has been removed, freeing up space to make a 56 cell (52V) battery, without compromises.
• The slider on the King Shark has a metal support and it has fixing points along almost it’s entire length, so you shouldn’t have any trouble to fit it to the standard bottle mounts on most bikes.
• The tabs on the base of the King Shark case are ~5mm thick and well supported. There are 8 of these stronger tabs and they are more evenly spaced along the entire length of the battery.
• Material thickness is ~3.3mm or more and there are numerous supports within the case, to improve rigidity and strength.
• The EM3ev King Shark case is designed for 56 cells, including cell holder and BMS. We design and manufacture the CNC cell holder, so it is a snug fit inside the case.
• We have designed and manufactured custom terminations for this layout, with cell level fusing on every cell, whilst also minimising voltage drop, to make the EM3ev King Shark 1 of the safest Ebike Batteries on the market (regardless of price).
• We have fitted 1 of the most advanced BMS you will find in any Ebike Battery to keep the battery safe, performing 100%, to be reliable for the long-term and to give the user access to data for info and diagnosis.
• Our King Shark comes with a high current charge plug, rated for around 8A.

A little info about EM3ev and their Batteries​

EM3ev builds battery packs (and design/manufacture most of the key component parts on our own high-tech machines). We have been assembling all our own battery packs since around 2011. We build our own battery packs, as we want to do things right, we want to do everything we can to make our batteries safe and we want to innovate. EM3ev packs are always conservatively/accurately rated with regards to both their capacity and the discharge current they can provide, which will help to ensure our packs provide a long and reliable service life.​

On top of all this, we stand behind our products (1 year warranty). And WE WILL fix any issues that occur (with minimum inconvenience, no cost to the customer and no we do not ask customers to return parts to China!). Here at EM3ev, we are not about hype, spin and self-promotion, our reputation was built the old fashioned way, by happy/satisfied customers.​

Em3ev King Shark 52V Ebike Battery Specs:​

• 58.8V 2A (fan-less) or, 4A, 5A and 6A chargers are optional extras. These are good quality chargers (very reliable in our experience). (The charger may differ from the images shown).
• We conservatively rate the cells as 4.9Ah per cell. Although the makers classes them a little higher than this. Like with any Li Ion type battery, best long term performance is obtained by not using all of the available capacity all of the time, and also, by not using the pack at high discharge rates which will cause excessive cell heating and premature aging.
• Cycle Life estimated at 500-700 cycles plus (1C discharge to 2.75V, 1C charge to 4.2V). Cycle life is extended by charging to 90%, limiting discharge to 90%. Our 5A charger has a switch for either 90% or 100% charge, or choose the Satiator for even more control. Our BMS doesn’t need a full charge to balance the pack, it will happily balance the pack with only 80 or 90% charge.
• Cycle Life will be reduced if the Pack is regularly used at continuous high discharge rates (our BMS does have over-temp protection if the battery gets too hot). Therefore, please match the battery pack to the rest of the kit to get the performance and long term usage you expect (see our suggested max discharge current below, for our recommendations).

Recommended Max Discharge Current for each Cell Type of the Em3ev King Shark 52V Ebike Battery:​

• Samsung 50E: ~39A Continuous, 55A Max Burst Current

Please note we recommend a max of no more than 50A for the BMS. The trip current is set to 60A for 1 second.

Note: the cell manufacturers specs are higher than our recommendations above. It will not harm the battery to occasionally discharge at higher levels than our recommendations, but regular, sustained high discharge rates will degrade the battery more quickly and the battery voltage will sag at these high power levels. The Battery BMS is programmed to trip if cell temperatures reach 60degC during discharge and 45degC during charging.

Capacity Specs for each Cell Type of the Em3ev King Shark 52V Ebike Battery:​

• Samsung 50E; 36V nominal, 19.6Ah, ~706Whrs

Note: the above figures are on a new battery in warm weather and at a discharge rate of ~0.5C. Cold temperatures or high discharge rates will result in reduced capacity. Capacity will degrade over time and usage. 48V batteries are not actually 48V. They are 46.8V as they use 13 series of 3.6V nominal cells (13*3.6V = 46.8V).

Em3ev King Shark 52V Ebike Battery Weight and Dimensions:​

• Maximum dimensions of: 95mm thick. 103mm tall, 358mm long (See the outline drawing in additional images, for details). Please allow about 18mm forwards and 8mm upwards for the battery to clear the slider that attaches to the water bottle mounts.
• Weight: approximately 3.8g (including slider).

We do not recommend that the battery is fitted upside down. If there is no choice to fit the battery in this manner due to frame design then it would be highly advisable to use additional straps to secure the battery. We do not condone the fitment of the battery in this manner.

 

[Gionnirocket]

My Jenny 10Ah battery from 4.5 years ago with Sanyo GA cells is still running strong. About 6 months ago I fitted this small battery to my 1000w Ultra bike and it performs very well for its size. Still takes a full charge and runs deep so there is no sign of the cells becoming unbalanced.
Is it state of the art, no. But I feel it's a solid dependable battery.
My problem getting something from EMVE3 is that their selection and ability to do a custom builds is very limited.

 

[-sandro-]

I'm disappointed. It's a nearly average build. Absolutely featureless BMS.
The best of the 6 makers we worked with and sold was EM3ev. Unbeatable quality but somewhat limited choices. Reention cases, Bluetooth BMS, fused cells, and more.
An Irish expat's factory in China.

We finally did it, it wasn’t easy, but we finally developed a Compact 36V Shark Battery with 40pcs of 2170/21700 cells. This a big step forward in every way from the original EM3ev 18650 shark batteries. Using the knowledge and experience we have gained over the years, we have made an even safer battery, with better energy density, with better fusible nickel terminations and an interconnect PCB (with fusing). We also created a new, smarter BMS, with great logging capabilities, with high current, that fits in a tiny footprint.​

So why is the EM3ev King Shark, King and why is the latest Shark Family from EM3ev a cut above the rest?​

This is why:​

• We assemble ALL our batteries in our factory, using custom parts we design and then manufacture on our own CNC machines. We don’t buy from Battery Pack Assemblers that sell at the lowest price to attract buyers, but then have to scrimp on everything, then assemble them as quickly/cheaply as possible, so they turn a profit. We don’t take chances when it comes to our batteries or your safety!
• We only source genuine A-grade genuine cells from the official sources.
• The EM3ev King Shark case is built and designed for 56 cells (the case itself is bought in from our preferred case maker). We were not willing to sacrifice safety and reliability by squeezing 56 cells into the Hailong case, that was only ever intended for a max of 52 cells, which is why we waited until a suitable case was available, before we offered our 52V EM3ev Shark batteries. The only way it was possible for others to offer a 52V battery in the Hailong case, was to discard the standard cell holders and glue the cells together.
• Our EM3ev King Shark uses an in-house designed and manufactured CNC cell holder which keeps everything safe, solid and secure. The quality and construction of the injection moulded case is also (in our opinion) far superior and the slider mountings are on a totally other level to the Hailong. The slider is solidly constructed and even has fixing points that match most water bottle mounts. No drilling holes or adding additional brackets to make it work!
• Every cell in the pack is fused (just like almost all of the batteries we supply). We have been designing and manufacturing (in-house) our own battery terminations for several years already. Cell level fusing, means that in the event of an internal short circuit in the battery (which the BMS cannot protect against), then all that will happen is that some sacrificial links will safely open, preventing any of the cells or cabling from overheating and becoming dangerous. CNC spot welding ensures consistent weld quality and weld position. Finally, our new PCB design offers better internal cable management and routing. Safe by design!
• We use a high tech, fully programmable UL-certified Smart BMS, which is rated for genuine 40A continuous plus, with a programmable over-current trip set to >60A (which is ample for the intended application). Our BMS balances during charging (when charging and when at >50% charge) and therefore doesn’t require a full charge in order to balance. Auto power off function, auto power on and with a pre-charge function (no sparks, so long as the battery is powered off when linked to the controller).
• This is a 3-wire BMS with separate charge and discharge circuits. The charge port doesn’t not output the battery voltage and will avoid sparking if you forget to power on your charger prior to connecting it. Like all our batteries, the King Shark supports regen.
• We do have a battery parallel balancing device called a dual battery balancer that can be used for running two batteries in parallel under all edge cases. The battery parallel balancing device works from 10S (36V) to 14S (52V). As long as the voltages of the two batteries are the same – eg. both are 14S etc. it will work with all cell types and capacities. The dual battery balancer has a max discharge current of 60A and regen is not permitted. Please contact us if you are interested in this device.
• High current charge plug comes as standard (approx. 8A rated). We don’t use the standard DC2.1 connector (fitted to most of this style of case), that is only rated for 3A and is likely to melt at much more than that.
• We do all this and offer it at our usual low pricing, we don’t charge a premium for Safety and Reliability. Just because we offer low prices, it doesn’t mean we don’t stand behind our product if there is an issue. We have a proven track record of offering great after-sales support and warranty repairs/replacements. We will not leave you stuck (1 year Warranty, with several Support Centres World-Wide). Our batteries are designed to be easily repaired if the need arises.

Features of EM3ev King Shark Case:​

• The controller case in the slider (that most do not even use) has been removed, freeing up space to make a 56 cell (52V) battery, without compromises.
• The slider on the King Shark has a metal support and it has fixing points along almost it’s entire length, so you shouldn’t have any trouble to fit it to the standard bottle mounts on most bikes.
• The tabs on the base of the King Shark case are ~5mm thick and well supported. There are 8 of these stronger tabs and they are more evenly spaced along the entire length of the battery.
• Material thickness is ~3.3mm or more and there are numerous supports within the case, to improve rigidity and strength.
• The EM3ev King Shark case is designed for 56 cells, including cell holder and BMS. We design and manufacture the CNC cell holder, so it is a snug fit inside the case.
• We have designed and manufactured custom terminations for this layout, with cell level fusing on every cell, whilst also minimising voltage drop, to make the EM3ev King Shark 1 of the safest Ebike Batteries on the market (regardless of price).
• We have fitted 1 of the most advanced BMS you will find in any Ebike Battery to keep the battery safe, performing 100%, to be reliable for the long-term and to give the user access to data for info and diagnosis.
• Our King Shark comes with a high current charge plug, rated for around 8A.

A little info about EM3ev and their Batteries​

EM3ev builds battery packs (and design/manufacture most of the key component parts on our own high-tech machines). We have been assembling all our own battery packs since around 2011. We build our own battery packs, as we want to do things right, we want to do everything we can to make our batteries safe and we want to innovate. EM3ev packs are always conservatively/accurately rated with regards to both their capacity and the discharge current they can provide, which will help to ensure our packs provide a long and reliable service life.​

On top of all this, we stand behind our products (1 year warranty). And WE WILL fix any issues that occur (with minimum inconvenience, no cost to the customer and no we do not ask customers to return parts to China!). Here at EM3ev, we are not about hype, spin and self-promotion, our reputation was built the old fashioned way, by happy/satisfied customers.​

Em3ev King Shark 52V Ebike Battery Specs:​

• 58.8V 2A (fan-less) or, 4A, 5A and 6A chargers are optional extras. These are good quality chargers (very reliable in our experience). (The charger may differ from the images shown).
• We conservatively rate the cells as 4.9Ah per cell. Although the makers classes them a little higher than this. Like with any Li Ion type battery, best long term performance is obtained by not using all of the available capacity all of the time, and also, by not using the pack at high discharge rates which will cause excessive cell heating and premature aging.
• Cycle Life estimated at 500-700 cycles plus (1C discharge to 2.75V, 1C charge to 4.2V). Cycle life is extended by charging to 90%, limiting discharge to 90%. Our 5A charger has a switch for either 90% or 100% charge, or choose the Satiator for even more control. Our BMS doesn’t need a full charge to balance the pack, it will happily balance the pack with only 80 or 90% charge.
• Cycle Life will be reduced if the Pack is regularly used at continuous high discharge rates (our BMS does have over-temp protection if the battery gets too hot). Therefore, please match the battery pack to the rest of the kit to get the performance and long term usage you expect (see our suggested max discharge current below, for our recommendations).

Recommended Max Discharge Current for each Cell Type of the Em3ev King Shark 52V Ebike Battery:​

• Samsung 50E: ~39A Continuous, 55A Max Burst Current

Please note we recommend a max of no more than 50A for the BMS. The trip current is set to 60A for 1 second.

Note: the cell manufacturers specs are higher than our recommendations above. It will not harm the battery to occasionally discharge at higher levels than our recommendations, but regular, sustained high discharge rates will degrade the battery more quickly and the battery voltage will sag at these high power levels. The Battery BMS is programmed to trip if cell temperatures reach 60degC during discharge and 45degC during charging.

Capacity Specs for each Cell Type of the Em3ev King Shark 52V Ebike Battery:​

• Samsung 50E; 36V nominal, 19.6Ah, ~706Whrs

Note: the above figures are on a new battery in warm weather and at a discharge rate of ~0.5C. Cold temperatures or high discharge rates will result in reduced capacity. Capacity will degrade over time and usage. 48V batteries are not actually 48V. They are 46.8V as they use 13 series of 3.6V nominal cells (13*3.6V = 46.8V).

Em3ev King Shark 52V Ebike Battery Weight and Dimensions:​

• Maximum dimensions of: 95mm thick. 103mm tall, 358mm long (See the outline drawing in additional images, for details). Please allow about 18mm forwards and 8mm upwards for the battery to clear the slider that attaches to the water bottle mounts.
• Weight: approximately 3.8g (including slider).

We do not recommend that the battery is fitted upside down. If there is no choice to fit the battery in this manner due to frame design then it would be highly advisable to use additional straps to secure the battery. We do not condone the fitment of the battery in this manner.

I don't understand, who write this?

 

[Bitmugger]

EM3ev doesn't sell a Dorado compatible battery, I have no idea why Tomjasz attempts to highjack this thread whenever people post to it. His post refers to a battery (Shark) that does not fit any bike that uses a Dorado style battery. He talks about a battery he ordered from Jenny that he admits he received and works well yet goes on about EM3ev and mentions distrust and getting scammed by a Chinese vendor that isn't Aijiu. I really don't get him.

Sandro my best advice is to ignore him if you are looking for a battery compatible with the Dorado system.

 

[-sandro-]

OK thanks.
The ones sold by Jenny how much do they weigh? I'm curious if they increased the energy density. For example my original 624Wh DeHawk battery is 4.3 kg.

 

[Gionnirocket]

The 21700 cells if they can be used are about 20% more energy dense than 18650 cells but in a relatively small predetermined size build like an ebike battery case, I don't think the weight difference will be significant enough to make a difference..