More Battery Milage / Juice ??

Due to the risk, what kind of precautions would I need to take in order to try and avoid ruining the controller as you mentioned? Reducing my speed, the amount of the time that I use the throttle, or is it a gamble? =)

Also, I'm curious... I was looking at the TNC web site and the batteries they sell at 12V / 12 amp hour / 20 hour rated (enduring) and the price is only $35.

I just purchased two new batteries from a local store (Batteries Plus) that the guy essentially picked the new batteries to match the old batteries I had : 12v / 18 amp hour / 10 hour rated and the price was $70 each!

What does the 18 amp hour part mean on my current battery, and how would I know if the 12 amp hour one sold on TNC would work with my set up??

An 'amp-hour' is one amp for one hour. An 18 amp-hour battery gives 18 amps for 1 hour (or 1 amp for 18 hours) versus a 12 amp-hour battery that would give 12 amps for 1 hour (or 1 amp for 18 hours).

Hence an 18 amp-hour battery will last longer than the 12 amp-hour one. I'm sure you like things that last longer, eh? However the larger battery will weigh more. The number of amp-hours is sorta related to how much lead is in the battery, so more lead means more amp-hours.

So long as the voltage is the same the controller will be fine.

Thanks, that helps. So if I understand you correctly, the battery offered on TNC would not last as long as the two that I purchased from the local shop. At least now I know that the additional cost was a little worth it, even if it was 2x the price. =(

Pulling all that weight, I'm suprised you get as far as 3 miles. Going to 36v would help since hub motors make more heat than motion when they go too slow. I suspect that with only 24v and that load, you are slow.

The easy solution is more battery, either a larger ah sise, or more batteries, two paralell, and two paralell, then the two sets, series connected to provide more ah of 24v.

To go to 36v you may need a new controller. Some can take 36, some not. We need more info to say if you can take that chance. At 36v you will be able to use less wattage to get started, and get about 6-8 mile range at least.

This is the controller that I purchased from TNC about two weeks ago and have been using it for about 3 - 4 days since I got the bike up and running : http://tncscooters.com/product.php?sku=101175

Due to finances I am using a recycled scooter motor that has been identified as a 24V United model with a 9.5A current as posted on the motor. But, a lot of the information had been scuffed off and I couldn't tell how many Watts it was. Based on a older thread (http://visforvoltage.org/forum/4789-please-help-ignorant-chick-electric-crap-unite-24v-motor-custom-ebike-mess) We determined that it was probably about 300 Watts, but certainly less than 500w.

Basically, cost is a major factor here. I am using this bike to take my daughter back and forth to school (about a mile one way), do grocery shopping, errands, etc. without having to use my SUV as much due to cost of gas & maintenance. I am not looking for more speed because I actually prefer to peddle along for the exercise. But, the extra load is a bit too much for me to peddle the entire trip on my own, which is why I opted for the motor assist. It actually goes almost too fast for me without the trailer and more than likely lasts a lot longer without that load too (I haven't tested/clocked it without the trailer). With the trailer, it is quite a bit slower but with my child on board I definately don't want more speed. I am just looking for a longer range because without the assist it's REALLY hard to keep that trailer moving on just MY peddle power alone.

I just called the local shop where I purchased my new batteries and found out that I have the option to trade in the two batteries that I just purchased and get 2 12v 26ah batteries instead of the 18ah I currently have. This option is only open to me today tho, so I'd have to make a decision quickly if I did this. Also, due to the added cost of upgrading the batteries... I wouldn't be able to afford to purchase a third one for another week or two. (assuming that I CAN run a third battery , total of 36V on my 24V set up?)

Comparing that option to the 3 battery option.... is the benefit of range better with the two 26ah, or with 3 of the 18ah? If its a matter of just adding the total of ah, then the two batteries is a total of 52ah at 24v, and the three would be 54ah at 36v.... again, assuming that I can run 36v on my current set up?

Suggestions welcome within the total price range of about $60 since thats all I have to play with right now. =)

Ah, we must teach you battery math.

This page may help
http://www.7gen.com/book/batteries-electric-vehicles/electrical-basics-covering-batteries-electric-vehicles/657

Basically when you connect batteries in series, the amp-hour rating stays the same and the voltage is added. When you connect them in parallel the voltage stays the same and the amp-hour rating stays the same.

2x 12v 18ah == 24v 18ah

2x 12v 26ah == 24v 26ah

2x 12v 18+26ah = 24v 44ah

I'm sorry, but I'm not sure I understand? If in a parallel connection the voltage AND the amp-hour stays the same... then what would be the benefit of adding a third battery using this type of connection? I understand that it wont affect my voltage, which means that I don't have to worry about upgrading anything to 36V, but how does it benefit my range if the amp-hour is still only 18ah?

Am I to understand that having a third battery allows the amps to be pulled evenly from each one, and that the more I have the longer my range will be in a parallel connection? But, this type of connection does not necessarily allow for more speed. The series connection would allow for more speed then, but not amp-hour.... right?

Based on your break down, are you saying that I could essentially keep the two 18ah batteries I have and add a third one of 26ah to increase my amp-hour/range? Does the amp-hour miss match cause any problems with running the motor or charging with my current charger that is currently working for my 18ah batteries?

What would be the best set up for a desire of more range? Two 18ah batteries and One 26ah connected in parallel - or Two 26ah connected in parallel?

Sorry about all the questions, I am trying to learn all of this as I go.

Oh yeah, and I've read some debate in posts about wire gage. Bigger is better? Should I rewire things with a larger gage wire? I'm currently using 14 gage wire??

When you connect them in parallel the voltage stays the same and the amp-hour rating stays the same.

Hi David - did you mean to say when they are in parallel the voltage stays the same and the amp-hour is added for the two in parallel?

But are they only added together if there are batteries with different ah specs? Because based on his break down it says that the amp-hour stays the same and things arn't increased until a third battery of 26ah is added to the Two 18ah batteries.... which was 18ah + 26ah = 44ah Right?

I think I'm getting more confused. =)

Oh yeah, and I've read some debate in posts about wire gage. Bigger is better? Should I rewire things with a larger gage wire? I'm currently using 14 gage wire??

A "smaller" gage number means a "larger" wire, so if you want a larger wire than 14 gage, you would go to 12 or 10 gage. For a 10A design, use 12 gage.

Oops, yes I knew that the larger the gage the smaller the wire. 12gage... gotcha!

Oh boy, I'm really sorry but I don't understand what you mean.

I can parallel two or four batteries... but not three? If thats the case then based on my available funds the best thing to do at this point would be to take the shops offer of allowing me to trade in my two 18ah batteries for two 26ah for a slight increase in range?

The 18ah ones that I already purchased were $70 each = $140

I can trade those in (today only) for two 26ah at about $85 each = an additional $30

If I opt instead to purchase two of the 12ah from TNC, then the total would be an additional $97 with shipping.

The most that I could immediately afford was about $60, which excludes the last option for now. But, if I get the 26ah now and then upgrade my range with two of thos 12ah at a later date.... well, then I'd be sitting pretty huh? =)

Awesome!

Now.... all of this got me thinking about the trailer. At a later date, can I add those two 12ah batteries and mount them to my trailer using a connection only when the trailer is in use? This way I only have to carry two batteries on my bike without the trailer, but when I hook up my trailer I have those extra batteries for the range I need from the added load.

How would I wire the bike battery set up AND the trailer set up so that they can be easily connected & unconnected quickly? Can I splice in a second battery connector on the bike set up and leave it unplugged when the trailer isn't in use? Will this work in a parallel set up by simply connecting that second battery connector to the trailer?

Like this?

Thanks for the diagram! Is Anderson Powerpole a brand of connector or controller?

make sure your 2 packs are reading the same voltage before you connect the two, or you'll get a massive rush of current.

How do I check the voltage? And how do I fix it if they arn't... sit around and wait for something to charge & catch up?

Also, would/can I connect everything together in order to charge them or is there a simplified way of putting a charging port on the trailer set up? A charging port would require another controller and all that mess, wouldn't it? =(

Hmmm, maybe my bright idea isn't so great after all. It sounds very complicated and I was hoping for a simple solution that didn't require me to contantly carry all of those batteries on my bike when the trailer wasn't in use.

I use the trailer about 80% of the time, but it would have been nice to make quick runs without it. However, all the measuring of volts, equal charging, etc. don't seem to be worth the convenience of being able to have seperate battery packs. lol

Thanks anyway. =)

I am REALLY upset, it's not been a good day for me at all. I was taking the wires off my two 18ah batteries so that I could trade them in for an upgrade today. In a hurry, and working with the batteries too closely together.... my wrench touched the other terminal while I was taking a bolt off the opposite battery and POOF! big sparks, smoke, and fire.... Yes, I said FIRE! One of the wires litterally disinitgrated before my eyes. I had to bang the wrench off one of the terminals because it was fused on there and some of the plastic casing on the top of the battery was melted and scorched. The upside is that the local shop tested the batteries (they were fine) and still accepted them for a trade in on the bigger ones I wanted.

I got two 12V 33ah batteries for only $20 more. But wait... my night gets better....

I get the batteries home and reconnect things, making sure the battery connection is last (isn't this the right way to do things?) and before I knew it... more sparks and smoke! Looks like the smoke came from the controller and the battery connections inside the plastic connector fused together briefly too. WHY?! Are the batteries to big or something for the controller now?

Thank god it wasn't the motor. I'm pretty sure it wasn't because I touched the motor ends to the battery and the wheel spun around like a bat out of hell.

My battery connections were made like this (same as before, ignore the key switch as it isn't connected to anything because I was told it couldn't be on this controller):

This is the controller I had and just fried: http://www.tncscooters.com/CT-201C6.php

Any ideas on what I did wrong and what controller I should replace it with? Gimmie good news, I need it. =(