Originally Posted by
rapattack
..I don't even have a concept of how much what i have weighs
Looking at another 7Ah SLA, yours are probably 6-7 lbs (2.7 - 3.2 kg)
each. Another 20 Ah battery weighs in at 15 lbs (6.8kg) , so you're probably looking at the double weight.
Originally Posted by
rapattack
..The bike is very strong....I can make a new bag
Yeah, but a 20 kilo load is no joking matter, particularly in the concentrated form of lead batteries. Both the bag and the arrangement by which you strap it to the bike must be very sturdy indeed.
Originally Posted by
rapattack
...i made a trailor and it easily pulls the shopping along.
That might be a part of your battery life issue. Another set of wheels can increase rolling resistance quite a bit. You'd probably get better mileage if you used panniers instead. Check the tire pressure on both bike and trailer.
Originally Posted by
rapattack
Oh the friend was sure that the batteries he mentioned were right and didn't say i would have to rewire.... Yes he told me i would have to get 3 just like the old set up
Rewiring was in case you were looking for a
single battery to replace your current pack. If you run 3 in series you don't have to rewire.
The charger you've got may not be able to deal with the bigger battery. It has the correct voltage, but as the bigger battery has a bigger capacity it will take a high charge current for a longer period - which can overheat the charger.
For the blue battery in your previous post it's clearly stated that a special type of charger should be used.