multiple times every year we see posts or get messages from individuals that have accidentally over discharged their packs and ruined their batteries . its usually they forget to plug it in or something malfunctions and the pack discharges . the dc to dc converts puts a constant drain on the battery packs and if not plugged in will destroy a battery pack in less than 8 weeks . Doesn’t matter if its lead or lithium they are history . average cost for the mistake is about $1800 .
Dave thinks he can make a plug in device that will automatically disconnect our dc converters if voltage drops too far and preserve our packs .if he can do it for under a $100 would anyone be interested ?
Now I’m on the spot!
Got sidetracked again. Maybe tomorrow.
Tnx for the vote of confidence.
You can do the testing to see what it needs to disconnect.
I have a dq with dc-dc . On those the red wire supplies the converter as well as battery charging.
That would be the place to connect it.
Other than that is there other phantom draw?
This is what happened to me: I left my gun cart in my toy hauler over the winter for 12 weeks where there was no electrical power to plug into. At least the two modules on the end of my pack have bulged out, as can be seen in the photos. My lithium battery pack discharged to 9.6V, ~ 88V - 90V is normal. The Zivan charger won’t start up at voltage that low. So I’m trying to charge small groups of modules with an automotive 12V charger. And Mike is correct; it’s at least a $1800 mistake. I’m looking into using a solar panel for battery storage charging in the future.
I need some testing done first.
From specs. Converter only uses 10ma in standby. My device will use that.
Need to find out where the drain is. How many amps, and where to disconnect it.
Here’s an update on my Leaf modules that were left to discharge for 12 weeks. I charged the whole bank with an automotive type manual 12V charger. I first tried an automatic charger, but that would shut off before putting much of a charge into the modules. I started with the whole bank up to ~12V, then I split the bank of 11 in two and charge each half to ~12V. I eventually ended up charging the modules in pairs to ~12V. When I got the whole bank to 68V, that was enough for the Zivan charger to kick in. I let it charge to 89.7V and took a drive around the RV Park and it seemed to have good power and the voltage wasn’t dropping any more than I remembered from last fall. I let it full charge again and left it over night and used it all day today with no issues. I ended the day at 86.3V and didn’t charge it tonight. I plan on using it tomorrow to see if I have any problems going 2 days on a charge.
Its been about 3 weeks since i brought my Leaf batteries back from the dead. They are still performing very well. I charge every 2 or 3 days, longer on days with light use.
Is there a reason the DC-DC converter needs to be powered on even after the key has been turned off and the circuit delay relay has tripped? I’ve seen my brake lights stay on even after I’ve turn off the GEM and exited(weak brake pedal spring) but a few minutes later they are off.
