Zephyr Battery Hanger, Preventing Cross Charge

[Tom MaCoy]

So from what I hear Tiffen wants $600+ for the Zephyr's second battery hanger, which I have to say seems pretty steep even by Tiffen's standards for what it is. I'm currently in the testing phase of building my own, and so far it's all been pretty straight forward; I have the plate (Endura v-lock base), the additional LEMO connector, and I can set it for series/24 volts (which I'd probably never use but like to have the option) or parallel/12 volts (which will probably be my default; still deciding if I want to work a 12/24 switch into the mix, or actually wire up two different cables to prevent getting bumped into 24). My only remaining concern is the above mentioned cross-charge in parallel, which I understand can be prevented by wiring a particular type of one-way diode into the circuit, though I haven't had much luck finding a specific model or type, or where it needs to be located beyond 'at one of the battery terminals.'

As far as I can tell, having pulled the base of my Zephyr apart and poked around inside, all the wiring between the battery power connectors is straight though (same for the factory battery plate), so whatever solution Tiffen uses in their system has to be contained within the wiring of the second battery plate. In other words, to mimic the factory spec, I need to wire the diode at either the positive or negative terminal of the second battery plate. Anyone by chance have a link or a recommendation for the right diode to get and where to wire it? Thanks.

-Tom

[Mark Schlicher]

Tom,

 

I'm pretty sure I've seen a thread or two that mentioned the appropriate diode, possibly under a "hot-swap" topic heading. Don't know the answer myself.

 

In 24V mode Tiffen's unit puts 24V on the third lemo pin, while still delivering 12V on the other pin, so that 12V aks still see 12V and the 24V is only seen by 24V aks. (Assuming appropriately-wired cables). Since there is only set of power cables up the post, every power connector gets the same feed: 12V only in 12V mode, and 12/24V in 24V mode.

[Tom MaCoy]

Thanks Mark. Some more digging under those keywords seems to imply this one is the preferred choice:

http://www.mouser.com/ProductDetail/STMicroelectronics/STPS60L30CW/?qs=sGAEpiMZZMuIUjt4yeP9c4vDnG6dExKEkEDEfs9dBHE%3d

I'm a bit surprised because (under my rudimentary-basic knowledge of electronic components) it has 3 leads, which I thought implied a transistor, but if I read right it actually just has doubled cathodes. Given that they're pretty cheap I'd be curious to know if there's any point or advantage to adding one to the factory plate as well.

 

I got the same voltage readings as you mentioned during testing; in 24V the meter reads 12v out of Lemo pin 1-2 and 24v out of pin 1-3. Just a matter of where the battery leads feed into the second LEMO port.

(PS, I'd PM'd back a couple shots of the dovetail plate I milled if you were still interested in having a look at it.)