Keep in mind many cheaper batteries are made in Mexico and from what I am told, they have cheaper materials used and less of it in them. They do not have a good track record so it seems. Try to steer clear of the Mexi-made batteries.
Also, look for group 31 batts if you want to go cheaper than the true group GC or GolfCart batts. The 27’s are not a real good choice if you can get the 31’s.
Have a 2006 gem e2, do replacement battery’s have to be gel?
The batteries don’t have to be gel, but if that’s what you have in there now and you change to a different type of battery then you will have to change the charger algorithm.
How hard is changing the algorithm?
It’s pretty easy to change but you need to have a charged battery pack to do it. Basically you have to apply voltage and disconnect voltage at set time interval to change the preset charge algorithms. The easiest way to do this is by having a friend watch the lights on the charger and you flip on/off the main breaker. I can’t give you the exact sequence to change it but if you google delta q charger reprogram you should find quite a few results, it doesn’t have to be GEM specific to change the algorithm but the gem chargers only have 5 algorithms to choose from which you should also be able to find online. If you can’t find what your looking fo let me know and I’ll track down some links for you.
Derrick