Skull diver Posted July 12, 2020 Share Posted July 12, 2020 10 hours ago, Joe Beechnut OBN said: while I am making a battery for it. Joe, are you using a bms module inside the 4s1p tube?I hope not because.... I actually don't know if I'm correct but seems to be the easier combination for a self balanced recharge without the need of multiple solder and little cables around cells, not to mention the module itself presence inside the pod... I'm developing a similar pack for the Tdi and can be the base for the future of my dreamed AQ... 1 Link to comment Share on other sites More sharing options...
PimentoUK Posted July 12, 2020 Share Posted July 12, 2020 Quote:" Are you using a BMS module inside the 4s1p tube? I don't know if I'm correct but seems to be the easier combination for a self balanced recharge .." Lithium-Ion cells don't self-balance, and have to be forced to charge correctly. This means either: A seperate charging connector bringing out all the cell terminals, (which will be 5 connections in the case of this '4s' pack) and charge with an appropriate balancing charger ( eg. R/C model charger ) or: A charge balancing circuit integral to the battery, allowing simple charging ( eg. current-limiting), on just the end terminals. In the case of using a seperate charging connector, the pack can be charged quicker, as all the thermal issues are moved to the charger, which can have high-power transistors/heatsinks etc as needed. A balanced charging circuit has less ability to juggle the currents through each cell, so generally they seem to be used in conjunction with slow ( trickle ) chargers. A seperate charging cable still means a battery protection circuit is needed, however, to guard against over-discharge, accidental overload/short-circuit, and possibly overheating. That is what the module pictured in OBN's post appears to show. It's also wise to fit 'gross overload' protection on a high-powered pack like this. That would include a conventional one-time wire fuse, a thermal fuse, and possibly a self-resetting 'poly-fuse'. I currently have a dismantled 5s lithium pack from a handheld Vax cordless vacuum cleaner. That has charge-balancing internals, and there's a surprising amount of stuff on the large circuit-board inside the pack, it's the full size of five 18650 cells. I also have an EBL 9 volt PP3 apart, which obviously is much lower power, and only two cells. There's not much to the balancing electronics in that. I don't know what techniques either of these packs use to achieve balancing, they are probably quite clever. 1 1 Link to comment Share on other sites More sharing options...
Joe Beechnut OBN Posted July 12, 2020 Share Posted July 12, 2020 On 7/11/2020 at 10:27 PM, Skullgolddiver said: Joe, are you using a bms module inside the 4s1p tube?I hope not because.... I actually don't know if I'm correct but seems to be the easier combination for a self balanced recharge without the need of multiple solder and little cables around cells, not to mention the module itself presence inside the pod... I'm developing a similar pack for the Tdi and can be the base for the future of my dreamed AQ... With the red batteries........ no...they can come out and will be put on a charger then another set dropped in... the other 4s2p yes 4 1 Link to comment Share on other sites More sharing options...
Joe Beechnut OBN Posted July 12, 2020 Share Posted July 12, 2020 3 hours ago, PimentoUK said: A seperate charging cable still means a battery protection circuit is needed, however, to guard against over-discharge, accidental overload/short-circuit, and possibly overheating. That is what the module pictured in OBN's post appears to show. It's also wise to fit 'gross overload' protection on a high-powered pack like this. That would include a conventional one-time wire fuse, a thermal fuse, and possibly a self-resetting 'poly-fuse'. Yes, have to have a poly fuse. .........I like these BMS modules they have a fuel gauge plug. Just have to see how much room I have once I get all together and maybe do a add on. 1 Link to comment Share on other sites More sharing options...
pjrough Posted July 13, 2020 Share Posted July 13, 2020 What is the turn down voltage for AQ? Building a battery pack for my waterproofed minelab etrac, I realized that it switches off at 9v, so no BMS was actually needed for my 3s lipo pack. I am not a huge fan of pulling battery out of the housing for charging them, so detector is fitted with 4 pin ip68 connector which is used for charging/balancing. (Blue cap socket is the connector, see photos below). So if AQ's lower voltage is 10v, there are li-ion cells with allowed low voltage of 2.5 volts, thus balancing can be moved to the charger. Or another way round, the AQ was designed for lithium battery, so maybe there is some sort of protection circuit build in the detector already. 2 Link to comment Share on other sites More sharing options...
Willy Posted July 13, 2020 Share Posted July 13, 2020 Putting things straight about batteries (specially Li-Ion) for the AQ (or for any portable device) Three different cases: Independent battery cells They are charged in parallel, the charger takes care of each separately in terms of current and voltage, automatic balancing Protected cells (a BMS circuit in EACH cell) These cells are slightly longer than the non-protected ones, the BMS is at the top. Highly recommended!! Unprotected cells NOT RECOMMENDED ( no protection against over-voltage, over-charging, over-current including short-circuit, thus, potential fire and explosion due to the Lithium) Battery packs (A BMS circuit integrated in the battery pack) For all the certified battery packs, a single BMS takes care of the battery cells separately. The charger connects to the BMS and not to the battery cells. The discharging current and voltage are defined by mixed configurations of nSmP (n Serial Cells to increase voltage, m Parallel cells to increase capacity) The initial design of the AQ was using a LI-ION BATTERY PACK (with integrated BMS) permanently sealed in the battery pod. Due to certification problems and high costs, this technology was replaced by a Ni-Mh pack which does not require as much care for airline shipping The final AQ version and the GOLD version will be shipped with good quality protected Li-ION battery cells as defined in above case 1.1. It will not be possible to use the SHORTER non-protected cells. 4 3 Link to comment Share on other sites More sharing options...
Willy Posted July 13, 2020 Share Posted July 13, 2020 10 hours ago, pjrough said: What is the turn down voltage for AQ? Building a battery pack for my waterproofed minelab etrac, I realized that it switches off at 9v, so no BMS was actually needed for my 3s lipo pack. I am not a huge fan of pulling battery out of the housing for charging them, so detector is fitted with 4 pin ip68 connector which is used for charging/balancing. (Blue cap socket is the connector, see photos below). So if AQ's lower voltage is 10v, there are li-ion cells with allowed low voltage of 2.5 volts, thus balancing can be moved to the charger. Or another way round, the AQ was designed for lithium battery, so maybe there is some sort of protection circuit build in the detector already. It was designed like that but there is no protection circuit in the enclosure, it was inside the battery pack. 1 Link to comment Share on other sites More sharing options...
Joe Beechnut OBN Posted July 13, 2020 Share Posted July 13, 2020 4 Link to comment Share on other sites More sharing options...
Joe Beechnut OBN Posted July 13, 2020 Share Posted July 13, 2020 Want to use the stock mounting system.. Still have to trim the clear tube, next will be carbon fiber tube..29mm ID ..would had been easier just to cut all up but to keep warranty machine must stay intact-ed. Replacing the shaft with Carbon then making the rear to fit the battery tube. Which would be 32mm CF piece 12.5 inchs / 317mm long section. With the handle and cuff.. NO wires...except the M-12 fitting out the rear for the Head Phones. Steve this set up looks like a picture you posted a few weeks ago on the battery.. 4 2 Link to comment Share on other sites More sharing options...
CCadrin Posted July 14, 2020 Share Posted July 14, 2020 I like it! 1 Link to comment Share on other sites More sharing options...
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