PowerWise Qe 48V Charger

[sonicj]

mightberight,
how did you come with your 14K value? i just figured this out the other day after 2 weeks of messing with it. i have a 11.1K resistor in mine right now, but planned to try a 10K thermistor taped to battery. i guess based on your value, 10k is wrong??? i noticed it didn't really do any conditioning, so maybe the 11.k is telling the charger that the batts are already boiling??? my charger is a 914-4810 btw.
thanx for chiming in!
-sj

[Scooter B]

This somewhat confused me. If I go with six 8V batts, what is the best way to charge them?

Would a 48V QE with a new female plug for the cart just wire right up and function properly?

What about the ProTech 48V onboard?

[MightBeRight]

Sonicj - Hey - good work! I also identified the thermister to be a 10k part. However, if you take one of the receptacles apart you will find there are two 2k resistors lurking in series with the aforementioned thermistor. 10k + 2k + 2k = 14k. I don't recommend you go to the effort of taking one apart since the entire thing is encapsulated however...

If you are using 11k, and the target is 14k, then the charger will think the battery is hot - and lower the charge voltage. I'm too lazy to figure out what temperature that is equivalent too, but I suppose we could figure it out. 11k means the thermistor is at 11k - 4k = 7k. What temperature do you get for your thermistor?

I've been trying to figure out how to encapsulate the thermistor (the real one is imbedded in some kind of plastic) to protect it from the battery acid. For now, I think adhesive heatshrink is probably best. Then affix it to the battery for as-good-as-new performance (I think). The real one is affixed to the battery post. Make sure there is NO WAY for the thermister or its wires to contact the battery post.

WRT 8V batteries: The PowerWise QE 48V is targetted to a 12V battery. Any 48V battery will "work", but the further one deviates from the target, the poorer the charging performance. Deviation is size, make, model, and age (and probably other stuff). I suspect an 48V pack of 8V will probably work ok. You will never achieve perfect - unless you just use the exact batteries that the EZGO cart comes with.

As usual - I can only say I might be right. I make no guarantees about the safety or soundness of what I say, and everything you do is at your own risk...

Glad to be able to help - I hate to see perfectly good chargers go in our already full landfills just because no one knows how to use them.

[sonicj]

MightBeRight, that some solid information man! i appreciate it! ok, this is starting to make more sense now. i noticed if i pinch a 10k thermistor between my fingers, i can send it down to like 7k which is low enough to shut off the charger. so, basically on a hot day it won't charge. the series resistors are the missing piece of the puzzle. i'll give this a try later and report back.

for potting, what about filling the heatshrink up with epoxy? a chap stick tube, a pen cap, piece of copper tube, etc., stick the thermistor & resistors in, fill with epoxy.

my charger is the yellow Quiq and I'm told it is set up for 4 x 12V trojan 1275s. im running 6 x 8V. do Ez-Go dealers just tell their customers they need a new charger if they want to run a different battery? or do they have the ability to re-program with other algorithms?
thanx again!
-sj

[sonicj]

were your resistors exactly 2K? not 1.8? or 2.2k?

ok, i built a probe... i used a 1.8 & 2.2 since i could find only one 2.0K. the pictures should explain the process. i'll fill the exposed end with epoxy. i guess i could have crimped & soldered it, but this will work about the same.
-sj

[sonicj]

close enough i suppose...

[MightBeRight]

Hey Sonicj - that was fast! And it looks good too. I can't see from your pictures, but the tube looks metal. I would have used plastic. If the thermistor makes electrical contact with the battery the whole thing goes up in smoke. The resistors were as 2k as 2k gets - 1% in fact, but you can use a 1k8 and a 2k2 to get 4k...

If by "the yellow one" you mean the one on the Delta-Q website, then its spec sheet says "The QuiQ’s intelligent microprocessor controller can store up to 10 Delta-Q developed optimized charge algorithms." And then "Manufacturing and field service personnel can easily toggle between algorithms and, with new field reprogrammable chargers, download new algorithms into the charger “on the fly.”" I don't know much about this topic so if you are using Trojan 8V batteries you could just leave it alone - since they are similar. If not, you could try calling Delta-Q to find out if there are any other algorithms in your charger and how to change them. Worth a try I suppose...

Good luck! And thanks for the great pictures!

[MightBeRight]

I did not see your last post until after I had replied. Does that meter do logging? It's hard to see the model. If so, you can do a charge cycle and log the results. If your charger doesn't have any other algorithms you can always log a charge cycle or two and check if its algorithm compares to whatever battery you have.