Dolphin Battery Case for Security AND Convenience ?

[jose]

I'm pretty satisfied with the first build; so what's next but to spend a little more dough improving things.

You can see from the pic it's got the ubiquitous nylon triangle bag holding the battery & controller. My biggest concern w/ the bag is the lack of security for the battery, when popping into the grocery store for 5-10 minutes. Of course there is no perfectly secure system, and I can accept a 1% probability of battery theft per grocery stop.

Q1: I am wondering how you readers feel about HOW much more secure the dolphin case would be compared to the nylon bag ?
If thought to double the battery security, then I'd be inclined to get the dolphin case.

Q2: Are some dolphin case designs are more secure than others?

Q3: On the convenience issue, I'm wondering if those of you w/ the dolphin case can easily remove it for battery charging or for long term security ?

Q4 If easily removable, I assume a quick-disconnect for the wiring is created external to the case. How is that done and what products can help w/ that?

Thanks for reading!

 

[d8veh]

It has a keylock on it and a connector between the battery and the holder. It couldn't be simpler. You unlock and pull off the battery. It takes about three seconds. You can't get the battery off without unlocking it because the locking pin is hidden, unlike the rack batteries that you can lever the keeper off the pin. Someone could kick one off if he can kick hard enough to rip the screws out of the crame.

They have a flat base, so fit to some frames better than others. I always add an extra rivnut to the frame to make it stronger and more secure. Some people complained of rocking when they had very narrow downtubes. You can solve that by putting some fibreglass on the frame before screwing on the holder and then letting the fibreglass cure so that it sets as a gap filler. You can use Sugru too, which is a bit less messy.

Stick to batteries with branded cells. They're more expensive, but much better than the unbranded ones.

 

[jose]

Thanks d8veh, jolly good of you to reply.

Just so I'm clear, the mounting plate has a connector that auto-mates w/ a connector built into the dolphin case?
If so, I'm guessing those connectors would not have enough pins to include my controller connections?; as I would like to house controller in the same case.
I suppose others here have created their own integrated male/female connection systems with how ever many pins they need?

Great tips on stabilizing the mount to the down-tube.

All set on the batteries w/ my Tumich 10s3p Li-ion. It does mean that I have to find a decent "empty" dolphin case; so any recommendations would be greatly appreciated!.

 

[amberwolf]

There are a number of discussions about the good and the bad on various dolphin case types, including problems with mounting plates/etc., if you are willing to use the search on "dolphin".

 

[Lurkin]

Q1: I am wondering how you readers feel about HOW much more secure the dolphin case would be compared to the nylon bag ?
If thought to double the battery security, then I'd be inclined to get the dolphin case.

As already noted, much more.

Q2: Are some dolphin case designs are more secure than others?

I have the one used by em3ev. Have a look at their website. As noted, issue was the frame is circular, bottom of mount flat. Solution was compressed foam and reinforced attachment to the frame by way of hose clamps round the frame.

Q3: On the convenience issue, I'm wondering if those of you w/ the dolphin case can easily remove it for battery charging or for long term security ?

It's perfect and couldn't be easier.

Q4 If easily removable, I assume a quick-disconnect for the wiring is created external to the case. How is that done and what products can help w/ that?

Yes. There is a corresponding plug/socket arrangement between the two that slots together as the battery slots into the mount.

Just so I'm clear, the mounting plate has a connector that auto-mates w/ a connector built into the dolphin case?

Yes look at em3ev's website/ Google. Pictures will explain it between than words.

If so, I'm guessing those connectors would not have enough pins to include my controller connections?; as I would like to house controller in the same case.

Would need to be a damn small controller to fit. I think it has been done, google is your friend. Probably not a great idea for cooling as the compartment is very small. I may be getting confused with an odd BMS arrangement.

 

[oobagooba]

Are some dolphin case designs are more secure than others?

On the convenience issue, I'm wondering if those of you w/ the dolphin case can easily remove it for battery charging or for long term security ?

If easily removable, I assume a quick-disconnect for the wiring is created external to the case. How is that done and what products can help w/ that?

They're all probably made in china to similar specs. Mine bolted to the bottle cage holes and doesn't move.

There is a spring-loaded carrying handle on top, flimsy but it works.

There is a tail piece with a plug to solder the output wires. The battery lifts off, it has a recess plug that matches the tail plug.

The charge port is exterior, no zippers, etc, no need to remove the battery if you can ride up to your charger.

My full suspension gives some cushion to the hard mount case. If your bike has no suspension an advantage to a bag imo is it hangs free and probably absorbs some road shock.

bmsb has a dolphin pack w/internal controller so it has been done
https://bmsbattery.com/ebike-battery/702-48v10ah-bottle-09-e-bike-battery-torque-sensor-battery.html

 

[d8veh]

You can buy them from BMSBattery with a 20 amp sinewave controller included. The kit inludes throttle, PAS, motor wire, ebrakes and LCD. The controller sits in a compartment at the base of the battery mounting plate, so stays on the bike when you disconnect the battery. It's truly an excellent system and the controller is very good, especially the PAS functions, which are so good that they make the throttle virtually redundant.

The only problem with fitting these batteries is if your triangle is too small. You need to add about 25mm to the length and height to allow for the battery removal. OP won't have a problem because he has a large triangle.

Despite what others say about the mounting plates, there's nothing that should stop you from fitting one other than not enough space. I've fitted loads of them and never had a problem. Occasionally, the clinch nuts in the frame for the bottle cage are in the wrong place. It's a 10 minute job to add another one and they only cost a few cents.

Some bikes don't have bottle cage nuts, but as I said above, as long as you have a large enough triangle and a straight part of the downtube, you can fit your own clinch nuts (rivnuts).

If you have any problems fitting one, ask here. The only guy I know that posted about a problem fitting one blabbed off about how to get a refund before asking how to fit it. Once he was told, he went quiet. I find that really annoying because other people might get scared off using this good battery mounting system.

The cylindrical and assymetric pod shaped ones have the strongest mounting plates. The new lower profile (Bosch copy) ones have a pastic mounting plate, which is not so strong if you're worried about someone kicking it off.

 

[jose]

Good replies all-around.

Oobagooba' description gave me a good visual of how these battery cases work. I couldn't find an empty "dolphin" case; but this "bar-type" is as close as I could find in my price range.
http://www.ebay.com/itm/Aluminum-CASE-for-bar-type-36V-48V-e-bike-EB-electric-bike-bicycle-battery-/121618916563

That size should accomodate existing Batteries, BMS & Controller. It looks like the rear panel unscrews; and with SOME work I may be able to fit a second set of mating (multi-pin) connectors for controller.
Ebay picture does not really show locking mechanism, which presumably engages the hole shown in the mounting plate. But I suppose it is reasonable to assume the kit can be finagled to lock-down to the bike?
I'd also have to paint that shiny aluminum for better stealth.

Many thanks!

 

[d8veh]

Those cases can take about 50 cells. The key switch is good for about 15 amps max. With 50 cells, there's not a lot of room for the BMS. They normally have a small square one 20A max. They come in different lengths. I have a few of them, so if you're serious about this case. I can tell you the exact length of a 50 cell one, so you can get an idea of how many cells will fit in that one.

 

[jose]

d8veh,
I should have been more specific in my last post on size needs for battery case.
My Tumich pack is 30 cells, 230mm long, so the 385mm (outside dim.) length of case should accommodate my battery, plus my 110mm controller in back and smaller BMS mounted atop the controller.
So w/ ebay seller info, I need not bother you for your measurements.
But I'm not quite ready to pull the ebay trigger yet, the height dimension is close, and I may have to ask seller to measure the inside height.

Thanks for the 15A info on the key switch; that is just enough for my BMS/Controller. Question tho, does the key also mechanically lock the case to the mounting bracket??

 

[Lurkin]

On mine, the only purpose of the key is to mechanically lock the battery to the battery mount so it does not get loose whilst riding/cannot be pinched off the bike. It serves no other purpose.

It is however, a different design to the one on ebay.

 

[jose]

Yeah, hopefully all of these cases with a key will actually lock to the mount; and be fairly secure from theft.

Thanks for Postin' and not just Lurkin'