LST Battery life
 

Hi there,

I buddy of mine recently bought a brand new Team Losi LST RTR, which comes with the JR XS3 set. He loves the truck by itself, but the only problem he is having is that when he uses the standard AA battery holder with brand new AA batteries, the batteries only last for about 1 tank of gas before the car gets uncontrollable and starts responding wierd. If new batteries are placed in the car, the car responds normal again.

I know it is recommended to use a battery pack in the LST, but still, I don't think it's normal to have a battery life of only ~20 minutes out of a brand new pack of batteries, or is it? How much runtime can be expected out of a fully charged 1200 mah rx pack?

Is the whole problem caused by the dual steerig servo? Or is there something wrong with the radio equipment that should be replaced??

Any advice is appreciated.

Regards,

Edju

RE: LST Battery life
 

I would bet that the battery holder is shorting out. The under tank pack will move forward and short out against the chassis. Put tape oround the pack and you should get at least 8-10 tanks out of a new 4 cell pack. The fit under the tank will be tight with tape around the pack so only put one wrap around it in any one place.

RE: LST Battery life
 

We actually put a baloon around it to make sure it wasn't the snow or anything, so that should prevent it from shorting too. The interesting thing though, when we did not place the battery holder underneath the fuel tank, but strapped it to the front of the car to the suspension posts, it seemed to work better..... Maybe it was still shortening out, even with the baloon around it??

Any ideas on estimated runtime on a 1200 mah rx pack?

RE: LST Battery life
 

Run time with a 1200 pack shoul be about 45 minutes at least. A new alkaline pack should be a somewhat longer. When it was strapped to the front of the car how much did it improve?

RE: LST Battery life
 

Regarding the battery pack up front: We ran it for about 15 minutes (we were at the lhs because we weren't sure about the battery life). When we came back, we put it underneath the tank and it lasted about 5 minutes more..... Not sure what the total runtime would have been if we kept it up front. We have it strapped to the front right now, but also received the rx pack, so not sure if we will actually be using the AA batteries anymore.... Just wondering if anyone had ideas on if this was normal. You are saying that AA batteries should last longer than a 1200 mah rx pack? I thought batteries were only rated at 200 mah or something??

RE: LST Battery life
 

well i run 2300mah AA's under the tank and to get 6 volts i wired in an extra 2300mah cell in the reciever box. works a treat and lasts a whole days use. need to be confident at soldering on to cells though.

stu

RE: LST Battery life
 

4 new AA's will only last about 3-4 tanks of fuel.

I have a 1200mah pack that was made for me by my LHS and it has lasted me for 2-3 hours of bashing. In fact, it has never died on me while out driving my truck. I just charge it before every outing.

RE: LST Battery life
 

The AAs Won't Last in the cold At All, And You can get a 1200-1400 mah Battery for around $30 You could go through that much on AAs in two Days, Plus You'll Get A way Longer Run time with the Receiver Pack.
I run Two 1200s one under tank & one in holder under the Truck and I can Run ALL DAY with Out Having to Charge them.
Hope thats some Help, Later Jason

RE: LST Battery life
 

Thanks guys! I appreciate the input! We'll do some testing and I will let you know the results.

RE: LST Battery life
 

Hi gang...Do any of you recommend a charger to charge the 8 batterys in the JR XS3. There is a charging jack at the base of the pistol grip radio. I know i would need rechargeable batt's and all. Any help greatly app.;)

RE: LST Battery life
 

Spend the money and buy the JR one, the plug is wired weird.

As for the truck.

I run two battery packs, 5 cell 1000 mah hump pack under tank ( now cable tied to inside front shock tower as I have a large fuel tank) and a 5 cell 1000 mah flat pack under the chassis. They are wired together using a Y cable and can be charged together or separately.

The best run has been four tanks until I broke some thing (I am known as the club abuser). After those four tanks if let them sit for a week until I got the problem fixed and then I used them without recharging to re-set my servos failsafe etc off and on for about an hour.

Use your AA’s for your radio, put rechargeable pack(s) in your truck.

RE: LST Battery life
 

I would recommend one, it's like a lump price at the beginning, but in the long run it'll save you MANY dollars worth of AA's and the extra weight of some spares in your toolbox;)

Plus, one guy said that on one charge of 2300 mah batts. in his Tx, (after he cycled the ma few times) they lasted him 2 gallons.[X(]

RE: LST Battery life
 

You can get Good Rechargeables,I have 2300mha NiMi there Better than the Jr set. Plus there only $3 Bucks a Battery.
I forgot, You can charge them in the Holder with Any Charger that has Clips and adjustable volts, I charge them at 1.2

RE: LST Battery life
 

I believe the good sgt is talking about me. I bought 2500 mah aa's off eBay and they lasted about 1 5/6 gallons, after cycling them twice. But to clarify one thing, I read on brand x batteries website awhile back that most alkaline aa's are 2500 mah. However, since there are only 4 cells (1.5 volts x 4 =6 compared to 1.2 volts x 5 =6) the rx pack will should last a while longer with the additional cell, provided it has a high mah rating. I have never even tried to run off regular aa's, but I am really surprised that they would only last a couple of tanks... they should be about the same as a 6 cell 1800 provided they are mounted where they will not short out. Of course one other problem with alkalines is that the voltage drop under load is fairly steady, where with Nimh's, there is an initial drop, then almost none untill near complete discharge. This is the likliest culprit, perhaps the rx doesn't work well with voltages below say 5.3 or so volts.

RE: LST Battery life
 

Yes, I was refering to you.

When the batteries are wired in parallel like they are in a batt pack, the longer runtime dosn't depend on the # of cells. In seris it does. Think of it this way.

You know who in a car you can power, or speed? (depending on the gearing. If you gear it low, you have maximum torque, but less top end, and vice versa.) Well it's the same with batteries, where mah is the power and volts is the speed. You can only have one or the other, not both.

So parallel makes speed, not power. In other word it adds the voltage of the cells, but has the same mah as only one of the cells. With seris, it takes the power, not speed. So if you have 5 1.2v 2000 mah batteries and you wire them in parallel, you get a batt pack with 6 volts, but 2000 mah. If you wire them in seris, you get a pack with 1.2 volts, but 10000 mah, or 10 amps.

So the extra cell dosnt contribute to run time, it gives more volts, because NiMH's need that extra cell, because they only run at 1.2 volts, instead of 1.5 that a alkaline runs at. But the NiMH's DO last longer because of the initial drop thing you said.

Just to clarify things up a little.;)

RE: LST Battery life
 

Sgt., I think you got your series & parallel backwards - a series connection increases voltage and leaves capacity (mAh) the same, where a parallel connection increases capacity and leaves voltage the same. Just clearing things up [8D]

I'm using Dynamite's 2300mAh conversion kit - comes with 8 GP 2300mAh AA batteries and a charger. Has worked great and allows me to run most, if not all, weekend long without worrying about Tx voltage.

http://www.horizonhobby.com/Shop/ByC...ProdID=DYN1975

RE: LST Battery life
 

Ah yes, I did. ;)

RE: LST Battery life
 

ehartman,

I had the same problem with my LST. I could only run 2 tanks on a set of alkies. I got some NiMH packs and still....2 tanks. SO.....I came to the forum and got lots of advice. A couple of the members recommended re-trimming ALL of the servos and re-programming the radio.

It worked!! I now get 6-8 tanks on a single pack. My servos were eating battery power even though the electronics were silent at rest. Just re-trim everything and you will probably fix this issue.

Good Luck!!