My get car always blinks 2 red lights at the end of every charge cycle, which I believe is a low voltage condition. I have GEM 31 batteries in my car and deltaQ charger, not sure how old but at least 3-4 years old. I can unplug the charger wait 10sec to clear the error and plug it back in till its green. My battsix monitor show that the voltage goes up to 81-82 volts after the second charge cycle. The batteries are well balanced. Is this a symptom of dying batteries? Am I killing the batteries? I’ve owned the car for 3 years and it’s hard to guage distance since the batteries get a serious workout on hills in my area.
Thanks
Get the serial and model numbers from your Q. Go on the net for Delta Q. and pick your model and you can download a manual. Check your batsix an hour after charging and I suspect the reading will have gone down a little. I understand this is a “settling” of the batteries (whatever that means). The Gem 31s should have markings on the top that is a code for year of mfg. I have a list of those and will see if I can dig it out of my “important don’t ever lose” box-the list is right there with the list of light codes also… The Q charger is very protective of charging the batteries. When it gets close to full charge it slows down the charge rate. I don’t think you are doing any damage plus Gem Manual suggests charging anytime the pack falls below 90%.
Getting the red might be because the program timed out before the battery pack was fully charged. (3 blinks)plugging the charger back in allows the charger to complete the charge. This doesn’t mean that there is anything bad it means the pack is getting older OR you may have 1 battery that is failing ahead of the others. If your getting the range you need don’t worry about it. If it bothers you just because it does. Have each battery load tested by somebody that is NOT trying to sell you a new pack.
Rodney
I’ll definitely check the battery code. I’m not happy with the range but the motor constantly overheats on the hills. I don’t know how much impact the hills have on reducing range but I’m assuming alot since my range is pretty poor. The mfg date sounds like a good place to start. I’ll call our golf course shop and find if they have a battery tester. Not sure if they have one since all their carts are gas.
All the batteries discharge at a similar rate so I’m fairly certain I don’t have a bad cell. It could just be an old pack.
BTW $1800 for a new set of Gel batteries is insane. I can see the appeal of going for lithium 
If you have an 99 with the 8.9 gearbox and your in the hills you should think about a 12.44 gearbox. If your getting 10 miles range your doing really good.
[quote=mski;32008]
BTW $1800 for a new set of Gel batteries is insane. I can see the appeal of going for lithium ;-)[/quote]
You can do lithium for much less that that, if you are a hobbyist.
If you want plug and drive, not so much.
Can save a gear change too. By dropping 400lb.
Not you, the lead!
A good compromise might be to consider AGM (Absorbed Glass Mat) batteries. sealed. no maintenance and appear to be getting ahead of the Gel batteries due to cost and easier charging. Very good grade of the AGM (Trojan-Dekka) would run under $200. each for the 12v.
I’d love to do the Lithium but since the car is at my vacation home it would be challenging. However dropping 400lbs would help tremendously on the hills. I’ve seen some drop-in 12v Lithium replacements for batteries but they are wicked expensive. Seems like the affordable option is buying smaller cells and putting them together. Any one have suggestions on how many amps of lithium cells would be needed to equate a comparable Lead acid battery given deeper discharge of lithium cells? What’s a good source?
AGM may be a good option but i have the deltaQ charger setup for gel, so there’s that, I’m not even sure my version of the deltaQ has AGM setting, much less trying to do the programming. After reading the posts on programming I’m a bit discouraged to try. But, for saving $600 I think I can give it a go. Worst case scenario I buy a new charger and still under $1800.
I definitely need the 12.44 gearbox but haven’t found one yet. Anyone have one laying around?
See the lithium threads for suggestions.
Not yet comfortable recommending for others, but putting two of these in, is pretty easy. 47ah
About $600 each on Ebay. I went the salvage yard route for much less.
With no programming changes, performance goes way up.
I run 12 to 15 miles in hilly area between charges. Actual run miles not maximum.
All it needs other than dropping in, is getting charger redone for lithium. $100
Small modification to allow controller to accept 100 volts.
24 cells must be occasionally monitored for balance. Less trouble than wet cells.
Leaf cells may be a better fit. Require assembly and connecting bms wires.
Near to turn key lithium swap as I can find. $2200. All new cells.
Includes chargers.
Li-ion 48vdc 50ah 2kwh NEW Battery w/BMS/charger Club Car Cart EV Boat Golf Cart
[quote=mski;32015]I’d love to do the Lithium but since the car is at my vacation home it would be challenging. However dropping 400lbs would help tremendously on the hills. I’ve seen some drop-in 12v Lithium replacements for batteries but they are wicked expensive. Seems like the affordable option is buying smaller cells and putting them together. Any one have suggestions on how many amps of lithium cells would be needed to equate a comparable Lead acid battery given deeper discharge of lithium cells? What’s a good source?
AGM may be a good option but i have the deltaQ charger setup for gel, so there’s that, I’m not even sure my version of the deltaQ has AGM setting, much less trying to do the programming. After reading the posts on programming I’m a bit discouraged to try. But, for saving $600 I think I can give it a go. Worst case scenario I buy a new charger and still under $1800.
I definitely need the 12.44 gearbox but haven’t found one yet. Anyone have one laying around? :D[/quote]
I use my GEM with lithium batteries at my vacation property and it has been working fine so far. I have my GEM connected to a timer that is on for 2 hours/week. The bms (battery management system) turns on the charger for some short length of time during that 2 hour window, based on the bms readings. During the winter I bring the GEM home and maintain the voltage around mid-pack. So far I’m pleased with this solution.
In terms of where to start for lithium, I suggest the following as a starting point:
Determine your desired range (e.g., 32 miles). A lightened GEM with lithium should easily reach 4 miles per KW-hour battery pack. So, in this example, an 8KW-hr battery pack will comfortably get you 32 miles. You multiply your cell nominal voltage x ah rating x number of cells to figure out your battery pack capacity (KW-hr). From here, determine how many battery cells you need to purchase based on your desired GEM voltage and the appropriate nominal voltage per cell. With number of cells determined you can then calculate the ah rating per cell you need to attain the KW-hr battery capacity. Now you have the number of cells and the ah rating you need, you can decide if lithium is in your budget. (Sorry for the complicated procedure. Maybe others on the forum have a better or simpler method.)
I’ve had good luck with CALB batteries while others on this forum have had great success using Leaf batteries. It is important to know the cell specs. You don’t want to charge above the max charge voltage, let them go down below the minimum charge voltage, and discharge at a rate faster than the max discharge current. If you stay within these specs you should be rewarded with a great GEM battery solution.
RWD
I think you’re right on.
2 of the above mentioned 2kw packs get me around 16 miles.
I charge after 10-15 miles.
Didn’t need more mileage.
Price is always my first concern. That leaves me more money to waste on useless projects.
I have about $650 in my conversion. Plus $100 for charger programming.
For another $650 could double mileage.
Either parallel or a reserve battery.
[quote=Inwo;32017]See the lithium threads for suggestions.
Not yet comfortable recommending for others, but putting two of these in, is pretty easy. 47ah
About $600 each on Ebay. I went the salvage yard route for much less.
With no programming changes, performance goes way up.
I run 12 to 15 miles in hilly area between charges. Actual run miles not maximum.
All it needs other than dropping in, is getting charger redone for lithium. $100
Small modification to allow controller to accept 100 volts.
24 cells must be occasionally monitored for balance. Less trouble than wet cells.
Leaf cells may be a better fit. Require assembly and connecting bms wires.[/quote]
So it turns out that the batteries are six years old. I think that’s the problem. I refused to pay $1800 for s new set of gel batteries. AGM would be a great option except for the fact that my deltaQ is an older model made for GEM cars and I believe doesn’t not have the profile for AGM cells.
That leaves me with lithium. I think I’ll explore looking at these battery pack. Do those leaf cells fit into the existing battery compartment? Do you connects a BMS to each 48v lithium module or to the individual cells?
What kind of charger do you use or recommend for lithium? Does the charger need to be 100v?
[quote=RWD;32020]I use my GEM with lithium batteries at my vacation property and it has been working fine so far. I have my GEM connected to a timer that is on for 2 hours/week. The bms (battery management system) turns on the charger for some short length of time during that 2 hour window, based on the bms readings. During the winter I bring the GEM home and maintain the voltage around mid-pack. So far I’m pleased with this solution.
In terms of where to start for lithium, I suggest the following as a starting point:
Determine your desired range (e.g., 32 miles). A lightened GEM with lithium should easily reach 4 miles per KW-hour battery pack. So, in this example, an 8KW-hr battery pack will comfortably get you 32 miles. You multiply your cell nominal voltage x ah rating x number of cells to figure out your battery pack capacity (KW-hr). From here, determine how many battery cells you need to purchase based on your desired GEM voltage and the appropriate nominal voltage per cell. With number of cells determined you can then calculate the ah rating per cell you need to attain the KW-hr battery capacity. Now you have the number of cells and the ah rating you need, you can decide if lithium is in your budget. (Sorry for the complicated procedure. Maybe others on the forum have a better or simpler method.)
I’ve had good luck with CALB batteries while others on this forum have had great success using Leaf batteries. It is important to know the cell specs. You don’t want to charge above the max charge voltage, let them go down below the minimum charge voltage, and discharge at a rate faster than the max discharge current. If you stay within these specs you should be rewarded with a great GEM battery solution.
RWD[/quote]
Thanks, that’s a great starting place for me. I’ll probably be looking in the 4-6kw range. CALB seem very nice but a bit on the expensive side. I may go that route but I might look into leaf cells first. Where did you get your cells from? What charger are you using?
Look for gwest lithium thread.
He has pictures of installed leaf.
The leaf cells fit perfectly.
Most of us don’t use bms. Instead we use the bms wires to monitor cell voltage.
If you have DQ charger, it can be programmed for any reasonable number of cells. Up to 24. As mine.
Now that I look again. You may be referring to my link. They are Chevy Volt.
I used Volt batteries, but only to save money.
AGM’s work on Flooded setting
Well then. That makes things easier but lithium is calling my name now. It’s hard to ignore
Placement examples.
Before I let go of this topic/post and not knowing your ability or knowledge level, I’d like to give you one more piece of advice. Forums are great but nothing replaces someone you can talk to or see their project first hand and ask questions. Most are willing to share why they did what they did, any regrets to avoid, may know of local businesses to obtain parts, and they can also come over and check your work.
I can think of a couple options regarding finding a local expert:
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You can attend or join an EV organization. For example, the EAA (Electric Auto Association) is a nationwide organization. There are chapters throughout the country. Don’t think there is one in Amarillo, TX but you may be able to stop and visit a chapter on a trip. Often these organizations may put on a show that includes several conversion projects that you can see at one location.
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There are sites that you can use to connect with other EV people outside of an organization. For example, evalbum.com is one of the larger web sites I know of where people show off their EV projects. Don’t just search for “GEM” on that web site but also search for location. You may discover someone who did some EV project that is similar to what you want to do that isn’t too far away. You can even take a weekend trip and visit multiple people and projects and glean from each of them. You may discover local places to obtain parts or make a friend in the process.
RWD
Thanks RWD for the good advice. I’ll check around. Much appreciated.