Hi again
I am asking your view on using an external DC power source for charging the 12V battery setup of 2x250 Ah (AGM lead acid, parallel). I recently acquired a Traco Power TXN-350-115 with 15 VDC output at 22 A. Intend to adjust the output to 13,6 V, which corresponds to battery recommendation for standby use (PowerXon). The max output can be taken from only one of the 3 output ports, right ?
According to this idea I use only float voltage for whole re-charging cycle (neglecting the boost range up to 14,4 V). The battery limit for initial current is 66 A (=132 A for the pair). There is a 63 A fuse at inlet to the pair (+pole).
This would form a parallel recharging system to a solar panel system during low luminous winter time. It relies on a running diesel generator.
I assume - like using ordinary car rechargers - the + terminal of the PSU is to be connected to battery+. Correspondingly in minus side. Ok ?
Would this be feasible or shall I think it over ?
regards
Juha
Hello,
We are looking into this now and will get back as soon as we can make a good recommendation.
Thank you
Ryan
Looking this over I seem to think it could work technically as the generator is doing the AC supply correct ?
Max power would be from 1, 2 or 3 channels but not all 3 as you mention.
Thank you
Ryan
Each of the 3 connectors on the + and - sides are directly connected to each other. The entire 22A output of the supply cannot safely be carried by smaller wire sizes, so multiple connection points are provided.
That’s how it would be connected if you were to attempt to use the device as described, yes.
It is not an ideal solution, because the TXN-350-115 is designed to be used as a power supply, not as a battery charger. Even with the supply adjusted to minimum output and with the battery pack only slightly discharged, your battery bank will attempt to draw more than the 22A that the supply is rated for, causing it to enter its over-current protection mode. The behavior of the supply under these conditions is not specified, and its reliability may be adversely affected.
It may be possible to work around this by connecting a suitable resistor in series, however this means that a substantial amount of the power provided by the supply will be turned into heat instead of charging your battery, and already-long recharge times will be extended. Appropriate cooling for the resistor and protection for the surrounding items is necessary.
Additionally, some power supply devices will be damaged (violently) if a voltage source is present at the output when input power to the supply is connected. This could be guarded against by connecting the supply through a suitable diode. Such a diode would also require appropriate cooling.
In summary, while the TXN-350-115 could probably be made to work for the purposes described, you’d probably be better off spending a bit more on a device designed specifically for the task if that option is available to you.
Hello Ryan
Yes, the diesel generator supplies the 220 VAC to the AC/DC converter. However, as informed by Rick, the stability of the DC supply device might get lost in over current range. How does the overcurrent limitation work actually ?
Accordingly, at present I am looking for a charging unit with applicable properties.
Best regards
Juha
Hello Rick
thanks a lot for your information. I think your recommendation of a proper recharging unit is worth considering for an improved system behaviour.
The retailer of the battery pack had given an optimum charging current of 50 A with 25 A each. Based on this the model NPB-750 might be a suitable option with 43 A as max amperage (boost) at nominal 12 V.
The link to the technical data sheet did not reach the actual file. Is this available somewhere else in your system ?
Best regards
Juha
The broken datasheet link has been reported, and in the meantime it can be found on the manufacturer’s site at this link.
A device like the NPB-750 would be a much better solution and reasonably sized for the battery bank mentioned. The multi-stage charge profile and temperature compensation feature would likely result in more effective charging and longer battery life.
It depends on the device. Some shut down and attempt to re-start, some shut off and stay that way until they are reset, others will reduce output voltage until current is within allowed limits. One doesn’t know if the manual doesn’t state it…
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Hi Rick
thanks again for advice. Got the specs file of The NPB-750 . It really seeems to be very versatile with various ways of adjusting the performance by manual setting and external programming. Beside the device some accessories may need to be ordered:
- 14 pin housing HRS DF11-14DS (by Molex)
- 20 terminal wires HRS DF11-""SC (really ?)
- programming unit SBP-001 with communication wire (to be considered)
regards
Juha
Hello guys
still the obvious question: what possibilities do I have to return the DC supply TXN-350-11 to you ? Have to admit that this move was my mistake due to my ignorance. I would order the battery charger NPB-750 with accessories for replacement.
Regards
Juha
Hi Juha, the best way will be to contact customer service via email at customer.service@digikey.com. They will want to know the invoice or order number, and will be able to issue a return if necessary.
[quote=“juha.tiensuu, post:8, topic:47185”]
20 terminal wires HRS DF11-""SC (really ?)
Juha
The
- 14 pin housing HRS DF11-14DS (by Molex) this housing is made by Hirose orur part number is H2140-ND
- 20 terminal wires HRS DF11-""SC (really ?) you only need either 14 of the contacts in the link below for the housing above , you will have to narrow down by the wire size you are using to make the connections , or the second link is pre made wires we have to offer .
[Rectangular Connector Contacts | Rectangular Connectors | Electronic Components Distributor DigiKey
](Rectangular Connector Contacts | Rectangular Connectors | Electronic Components Distributor DigiKey)https://www.digikey.com/en/products/filter/jumper-wires-pre-crimped-leads/453?s=N4IgjCBcoMxg7FUBjKAzAhgGwM4FMAaEAeygG0QAWABkvgFYAOEImugNhhatvneYC6RAA4AXKCADKogE4BLAHYBzEAF9VRAEzkQAEzRgIA1UA
Thanks Craig
The online self-service returns page can be found here, and registered users may also request returns from their My DigiKey page. Either of these methods will typically save a substantial amount of time compared to initiating a return request via email.
It should be noted that none of the accessories/ connectors mentioned are necessary for basic use of the NBP-750. Per page 13 of the datasheet, a suitable sensor for temperature compensation and DF11 connector housing with the necessary jumper to activate the remote control function are included. Charging parameters can be set using the DIP switches on the device.
Hi Chris , Craig and Rick
very grateful again for your assistance. Sent the order for NPB-750-12 and plug accessories just recently.
I understand that the charger operation in manual mode with the switches and panel settings is possible w/o any plugs and connection wires. Prefer anyway to have these ordered for eventual upgrades for automated operation.
I utilised the return request option of Mydigikey page for 15V DC source.
Thanks and regards
Juha
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