Start off simple. Only one bank of 24 (6 batteries).
Get the car running.
See how that goes.
Watch them closely.
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Typically an unmonitored lifepo system will start off working just fine. Depending on how hard it is worked (what a cycle looks like), the pack will become unbalanced and fail within a year (good thing these batteries cost him pennies).
Tip- the only way I can see something like this have a remote chance of survival is to wire it up with 6 individual chargers (set up for lithium). This plan is not ideal and has it’s own issues, but survival odds are better.
This way, the batteries are more/less getting topped off, sort of top balanced when charged.
By having ONE charger (the DQ) it is only concerned about the top voltage a combined voltage, then it shuts off. When unbalanced, low cells will not get fully charged, and high cells will get very overcharged.
I appreciate that advice, and I’ll pass it on to my customer. He is going to weight his options and then decide how to proceed. After reading your advice, I’m disinclined to offer him a battery pack tear-down and rewire simply because I’m not an expert on those systems and I don’t really want the liability of designing and building a home-brew battery that could create potential safety issues. If it was my vehicle, I wouldn’t be worried about diving into that project, but my rule as a professional is that I don’t take on work unless I’m sure that I can do a great job of it.
Now that I’ve got the charger connected properly, it charges for 30-60 minutes then sets and error and gives me 4 blinks. The DeltaQ troubleshooting guide says the following about that error condition:
Check Battery - This fault indicates the battery pack could not be trickle charged up to
the minimum level required for the normal charge cycle to be started.
• Check that none of the battery pack connections between modules are
reversed or incorrectly connected.
• Check that one or more cells in the battery are not shorted.
• Confirm that the nominal battery pack voltage is the same as the battery
charger voltage.
• Try the charger on a good battery.
• If this fault occurs the battery pack is likely in poor condition. Try to
recover the pack with a charger that can charge the individual cells –
such as an automotive charger. Be sure to set this charger to the
appropriate voltage – 6V per 6V battery, 12V per 12V string/battery.
You guys have any guesses as to what might be happening? When I unplug the 110V and then reconnect it, it starts charging again. My customer is happy with the progress I’ve made and is planning to pick up the vehicle next week, but I’d love to know for my own curiosity.
Thanks again!
What batteries are you trying to charge?
What profile is the DQ presently running?
This is more/less just saying the voltage is not coming up to where it is expecting it to be in the time expected.
Sometimes cycling the power off (unplug/wait 60/plug back in) will boost the pack up to where it works/finishes properly.
It’s connected to the current setup described in the original post - 12x of those Valence cells configured in 6 sets of 2 batteries. I’m getting 79.9V from the pack, so I don’t think low voltage is the problem. Maybe an intermittent short in a cell or something along those lines?
The charger has supposedly been programmed with algorithm 233.
Key word “supposedly” means that you have not checked.
- Disconnect the battery from charger outputs (Main [BatSwdisconnectOFF] so charger does not see battery)
- Plug in charger
- Watch the Charger display panel
-
- it will go through a quick boot up, pause fro a sec, then flash a series of blinks that indicate what profile is set.
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so I don’t think low voltage is the problem
DQ chargers have quite a bit packed into that yellow box. Not suggesting a low voltage in general (to what YOU may be thinking), but 233 may have a threshold V programmed into it that it is expecting to reach after a given set time. If not reached by that time, it assumes there is an issue and shuts down the charge and makes you look.
My notes show 233 as a profile for Samsung SDI 20a 12/48v modules. I have no info on what that battery is, or what that charge profile actually does(voltage/amp curves, pauses, peak charge, time, etc). Possibly whoever programmed this charger may have more info.
SWAG → This sounds like a capacity issue. Your 2p24s sounds like a HUGE pack that 233 does not know about. It may take more than 1 or 2 charge cycles to fully charge it. I just don’t know why it times out in 20~30mins? (I think that is what you said?).
But without a BMS to monitor what they are doing you have no idea. You are more/less flying blind.
Thank you for the explanation. That absolutely makes sense. I know very little about the charging algorithms, but the guy who was previously working on this project and a rep at the remanufacturing company that sold them the charger (FSIP) decided that 233 was the right algorithm. I’ll pass that explanation along to the owner.