Battery question

[curly33333]

The other day my cart died on me. It went from full speed to stop. I charged the battery's up and all is good. All water levels are good. I measured them with the volt meter and two (which have the 12 accesories hooked to)(6.3v) is measuring less voltage than the other four (6.5v). Does this mean I've killed those two batterys? Should I hydro test these to see if its just low acid level?

[scottyb]

Thanks for posting this.
Q#1= How much do you use your lights?

The batteries may not be the issue if the pack total is above 36v.
Q#2=Does the solenoid click when you try to go?

[curly33333]

The cart works fine. I haven't riden it much to see how long the batteries will last yet but charged up they have +36v.

Oh, I have light, radio, and a !subwoofer amp! for accessories.

[scottyb]

You may have triggered the low voltage cut off. Battery manufactures recommend you use a DC to DC reducer for your Accessories. The amp probably has a pretty significant draw.
Continued drain on 2 of the 6 batteries will cause problems in the long run according to the Techs at Trojan Battery Co. I recently posed this question to their technical staff and received this clear answer on the subject of DC>DC reducers:


Trojan Battery Response

Dear scott:

Thank you for submitting your question regarding Technical - Charger.

Based on your comments below:

Hello. We are have much discussion about the pros and cons of using a DC to DC reducer to run lights, radios, mp3 players, etc on our golf carts. Some say it is okay to use 12v from 2 6v batteries and other say this will cause an imbalance in the pack resulting in damage over time. What do you say? Thank you very much for your excellent technical support at Trojan Battery Co.

Below is Trojan Battery's response:

You should definitely use a DC to DC convertor to power any electric accessories. If not, the batteries that supply accessory voltage are over-used and under-charged compared to the rest of the pack. Since your cart's performance is limited by the weakest battery in the pack, the batteries running the accessories will reduce the overall performance of the vehicle. Thanks.

If you have additional comments or questions, please contact me at the information below.

Sincerely,

NAME
Product Engineer
Trojan Battery Company

[curly33333]

Thanks Scotty for the quick response. I planed to install a seperate 12v lawn mower battery to run the accessories but never got to it. I hope Im not too late.

[fishb8]

Well this is crappy news for those of us using 12v from the pack.

[fishb8]

So a DC to DC converter converts 36v (or 48v) down to 12v, but drains from the whole pack? isn't that a reducer.

[curly33333]

A DC-to-DC converter is an electronic circuit which converts a source of direct current (DC) from one voltage level to another. These are also known as 24, 36, or 48 volt voltage reducers, and voltage regulators. They closely regulate the output voltage over a range of input voltages. If you look at some of the site sponsors web pages you can find them from 80-125 bucks. It just matters how many amps you need, and some sponsors will give a 10% discount for BGW members.
Do as I say not as I do, I should have bought one of these. Now I probably will have to replace two 6v batteries that are not even 2 years old.

[fishb8]

Im thinking of buying a seperate battery for this. my batteries are 2 weeks old so I hope I can recover from this.