5590BAv2 Battery Adapter

© Brooke Clarke 2007 - 2019

This is the second battery adapter made for the BA-5590/U family of military batteries.  The battery consists of two independent "12 volt" batteries and the load can be wired to connect them either in series for a "24 volt" battery or in parallel for a "12 volt" battery.  The first 5590BA battery adapter was designed using 0.060" thick aluminum.  And these was no planning for the use of Sub C cells so it's difficult to get 20 SC cells into the first version.  Version 2 holds 20 SC cells close packed with a little extra room on all sides.

The lid attach method on the first version depended on bending parts of the lid inward to act as fingers that mate with slots on the sides of the main box.  The combination of the stiffness of the 0.060" aluminum and the length of the fingers made it difficult to remove the lid.   Version 2 uses 0.050" aluminum so the sides are more flexible and the inward pointing fingers have been replaced with what's called a lance.  This is similar to a punch that moves the metal about it's own thickness and leaves the punched metal attached.  Thus the new  "fingers" are much shorter making for easy lid installation.

The overall dimensions meet the 5" x 4.4" x 2.45" plus zero minus 1/16" outline of the BA-5590/U and the socket is where it's supposed to be so it's a form and fit replacement for any of the BA-5590 family of batteries.

30 April 2008 - top photo (above) shows 12 AWG wires with crimped connections.  The wire is super flex, i.e. there's a large number of very fine wires, not the stranding like used for house wiring.  They measure 1 milli Ohm each including the Power Pole terminal and the socket pin.  For more see the HP 4328A Milliohmmeter web page.

The adapter without any batteries weighs about 9 oz.

	Ver 1	Ver 2	Delta	20 SCPack 0.9"
High	4.729	4.876	+0.147	4.798
Wide	4.250	4.278	+0.028	4.050
Deep	2.245	2.335	+0.090	1.930

The SC cells used in RC racing cars have the ability to run at (30 Amps 2006 (2008 40 Amps) so an option for this battery adapter may be (idea stage) to use a different socket bracket to support Anderson Power Products "Power Pole" connectors using contacts rated for 45 Amps.

Twenty SC cells in series would have a voltage of about 24.0 when empty and with a current of 30 amps would be delivering 720 watts!  The parallel configuration would be 12 volts at 60 amps for 720 watts!

That's a lot of power.

The DARPA Wearable Power $1,000,000 contest is asking only for 200 Watts max power, but they want about 2 kWhrs weighing no more than 4 kg (8.8 pounds).  With 4.5 AH SC cells the capacity of the adapter would be about 20 * 1.2 V * 4.5 AH = 108 Whrs far short of the 2,000 Whrs they are looking for.  They specified the two voltages as 10 to 16 VDC and 20 to 32 VDC.  This is interesting because it eliminates Li cell batteries that produce a little more and have been know to blow out some equipment (Javilin) that can not handle the higher voltage.

The version 2 adapter weighs 3 ¼ pounds with the 3.3 AH SC cell pack, maybe a little more with 4.5 AH cells.

To support the Power Pole high current idea the internal wires need to be 14 ga or larger. 
15 Oct 2007 - A sample of 14 ga wire is on order to see if it will fit the connector pin solder cup (the dimensions say it's a little too big).


22 Oct 2007 - The 14 AWG wire will work with the connector solder cup.  Wire on order, here in a couple of days.

If the regular socket is used it makes sense to use the heavy wire to minimize IR drop even when lighter loads are being powered.
The problem is soldering the wire.  Extremely difficult.  The solution is to crimp the 14 AWG wire into the brass connector pin.

14 May 2008 Charging and discharging to see if capacity improves (what I was told).

Triton2 Charger & 4.7 AH 20 cell Pack	Load Testing EL1132 Electronic Load controled by Sony Viao w/ LabVIEW
Life Size (72 dpi) image showing Power Pole Connectors partially separated. Red is Receding. If you remember this alleration when it comes time to seperate a pair of Power Pole connectors you will know to push on the front of the red shell and support the back of the black shell.

The Triton2 charger can charge all 20 cells in series.  The wires on the battery pack do not have the Power Pole connectors impermanently paired up so they can easily be connected in series.  But the Triton2 has a charging power limit of 90 Watts so for a 28 Volt pack the current can only get to 3.2 Amps (which is what's shown in the photo at left) even though the set current was 4.0 Amps.  The set current would be used if the pack voltage was below 22.5 Volts.

In a similar manner the discharge is limited to 20 Watts, which for a 28 volt pack is only 0.7 Amps, not really enough to do much.  By load testing the two sides separately that can be doubled to 1.4 Amps, but still short of a realistic load.

You can see the thermal sensor plugged between the pack shrink wrap and the center cells.  So far it has not terminated charging but is a safety backup.

12 May 2008 - the battery pack weighs 3 lbs 1.5 oz.   When in the 5590BAv2 that total would be 3 lbs 11 oz.
                        At a constant 2 amps discharge it lasts about 4.1 hours (about 8 AH capacity).
11 May 2008 - Using 9 min Rx @ 320 ma & 1 min Tx @ 1.7 Amps, series connected 20 volt cuttoff.   The run time is 9.5 hours.
5 May 2008 - The pack is here and fits perfectly.  See top photo on this page.  Now for some electrical testing.  There are 20 each 4.7 AH cells in this pack.
2 May 2008 - The pack can be ordered from Cheap Battery Packs soon with a predefined configuration.
20 Elite 4 AH cells, copper bars, 14 AWG wire PRC68 configuration less than $150 including shipping to California YMMV
20 cells * 4 AH/cell * 1.2V discharged = 96 WH, at 1.3 Volts average maybe 104 WH so around 100 WH capacity.  These cells are rated to discharge 40 Amps.
That's 40A * >24V >= 960 Watts.  But the 5590 type connector can not support 40 Amps for very long.  An option would be to replace the 5590 socket with Power Pole connectors.
If the discharge rate was 1,000 Watts and the capacity is 100 WH then the time would be 0.1 hours or 6 minutes.  That's way too long for the 5590 connector would not take it.
When used in a radio the advantage is that the voltage drop during transmit will be lower than with a higher resistance battery and so you get more talk time in transmit.

11 Nov 2007 - The reason for my current focus on the high current performance is not so much that the load would be drawing huge currents all the time, but on the need to be able to supply a current higher than the average current for short periods of time.  Many devices have a startup power requirement that's considerably higher than their run current.  If the battery can not supply the starting power then it can't power the equipment.  Also by designing for the higher currents resistive losses are lowered for the lower currents.

1 Nov 2007 - The 20 SC pack made for the first version 5590BA has been refitted with 14 AWG wire and Power Pole connectors with 45 Amp contacts.  It drops right into the 5590BAv2.
A Triton2 Charger Discharger Cycler is being used to get this pack up and running since it's been sitting for many months.  The discharger can be used to evaluate how well another charger works with a limit of 3 Amps max.  The Amrel EL1132 can handle 300 watts, which at 28 Volts is a little over 10 Amp discharge current.  Testing at 30 Amps from 30 Volts requires a resistor of about 0.9 Ohms that's good for about 900 Watts.  Not easy to come by.

The 5590BAv2 may be sold as the box with secondary style socket terminated with short super flex 16 AWG wires terminated with a pair of 45 Amp rated Power Pole connectors (4 terminals) in standard ARES configuration.  And also offer optional battery packs.

20 SC Cell Packs

Packs are made using either spot welding or soldered copper link bars.  The table above shows only a few of the SC cells that are on the market.  Since the 0.9" diameter cells easily fit ver 2 commercial packs can be made without custom fitting.  The SC pack I made for version 1 just drops in with room to spare.

An interesting prospect is the ability of delivering 30 amps at 30 volts or 60 amps at 15 volts, i.e. 900 Watts.  The cells and wiring are up to it but I don't know about the connector.  I've heard that each contact can handle 10 Amps, i.e. good for delivering 10 A @ 30 V or 20 A @ 15 V for 300 Watts.

40 AA Adapter

This would be an adapter that can hold 40 AA cells.  It allows the use of Alkaline, Ni-Cad, Ni-MH, LiFeS4 (Energizer L91 1.5 volt Lithium), Sanyo eneloop Ready To Use (long shelf life) Ni-MH, or whatever new chemistry comes out in the future.  AA cells typically are where the newest technology shows up first.  Short wire leads with Power Pole connectors.  A string of 10 cells gives 15 volts so 20 cells is the number needed for the two sides to the 5590 family battery.  So you could install just 20 cells or for more capacity install all 40.

I'm investigating the eneloop Ready To Use Sayno AA cells.  They claim a much longer shelf life than other Ni-MH cells.  This is being done with a Maha C9000.

CR123 Photo Battery Adapter

The same idea as for the AA adapter, except for the CR123 photo batteries.  These are 3 volt cells so a string of 5 gives 15 volts so 10 cells is the minimum number to have a working 5590 family battery, adding multiples of 10 cells to give 20, 30, 40 or maybe 50 cells adds capacity.