Volt Meter

Nishan.dj · February 20, 2013

Here I have created a simple volt meter. I had to use 2 panels because I wanted to see the voltage of two batteries separately. This costs below Rs.1500 for me and display was bought from ebay. This is for my jeep and therefore could easily be fixed other than a modern car. It is really helpful for me to check the status of battery when the vehicle is idle for several days. I attached 2 switches to switch it on/off at the time I want. Thanks for reading. My next attempt is to fix a digital ampere meter as well. Happy DIY project for me. Hope yours too.

Sylvi · February 20, 2013

Here I have created a simple volt meter. I had to use 2 panels because I wanted to see the voltage of two batteries separately. This costs below Rs.1500 for me and display was bought from ebay. This is for my jeep and therefore could easily be fixed other than a modern car. It is really helpful for me to check the status of battery when the vehicle is idle for several days. I attached 2 switches to switch it on/off at the time I want. Thanks for reading. My next attempt is to fix a digital ampere meter as well. Happy DIY project for me. Hope yours too.

Nishan.dj,

Good attempt by young motorist. Do more useful new projects like above and write to the forum of your results. For other A/l members to know.

Very good idea you can check your Vehicle battery voltage of two separately as well as both batteries directly when they are in series.

The advantage of a voltage meter is you will be able to monitor the self starter operation voltage. Then when alternator is charging, charging voltage.

When the entire load is on on your vehicle how the alternator will operate.

Have to do separate wiring with a switching arrangement. Single rotary switch with 2 pole 3 way or 4 way will do all in one switch. 4 way One position off.

Switches are available in 1st cross street. two pole center off, rotary also, few hundred rupees high quality ones.

As you do not want a very heavy amperage. Reading is only voltage there are switches under 100.00 Rupees also.

Sylvi Wijesinghe.

Rumesh88 · February 21, 2013

Here I have created a simple volt meter. I had to use 2 panels because I wanted to see the voltage of two batteries separately. This costs below Rs.1500 for me and display was bought from ebay. This is for my jeep and therefore could easily be fixed other than a modern car. It is really helpful for me to check the status of battery when the vehicle is idle for several days. I attached 2 switches to switch it on/off at the time I want. Thanks for reading. My next attempt is to fix a digital ampere meter as well. Happy DIY project for me. Hope yours too.

Not only you are now able to monitor the status of individual batteries but you can determine if it is the time to give them an equalization charge. When two batteries are simultaneously charged from the same source (ie your alternator) they tend to get charged to different levels primarily because of differences in the temperature of the electrolytic (acid) inside the two batteries. If the terminal voltage of one battery differs from the other by more than a couple of decimal points (measured when the temperature of both batteries are supposed to be equal, like after the vehicle is left idle for a day), then you need to give the battery with a lower reading a equalization charge. Even swapping the position of two batteries may solve the issue but not always. If left as it is it will deteriorate both batteries because the one with higher terminal voltage will get overcharged while the other will be left undercharged. Nice work!

Nishan.dj · February 21, 2013

Nishan.dj,
Good attempt by young motorist. Do more useful new projects like above and write to the forum of your results. For other A/l members to know.

Very good idea you can check your Vehicle battery voltage of two separately as well as both batteries directly when they are in series.

The advantage of a voltage meter is you will be able to monitor the self starter operation voltage. Then when alternator is charging, charging voltage.

When the entire load is on on your vehicle how the alternator will operate.

Have to do separate wiring with a switching arrangement. Single rotary switch with 2 pole 3 way or 4 way will do all in one switch. 4 way One position off.

Switches are available in 1st cross street. two pole center off, rotary also, few hundred rupees high quality ones.

As you do not want a very heavy amperage. Reading is only voltage there are switches under 100.00 Rupees also.

Sylvi Wijesinghe.

Thank you for the detailed reply. Really appreciate it.

Nishan.dj · February 21, 2013

Not only you are now able to monitor the status of individual batteries but you can determine if it is the time to give them an equalization charge. When two batteries are simultaneously charged from the same source (ie your alternator) they tend to get charged to different levels primarily because of differences in the temperature of the electrolytic (acid) inside the two batteries. If the terminal voltage of one battery differs from the other by more than a couple of decimal points (measured when the temperature of both batteries are supposed to be equal, like after the vehicle is left idle for a day), then you need to give the battery with a lower reading a equalization charge. Even swapping the position of two batteries may solve the issue but not always. If left as it is it will deteriorate both batteries because the one with higher terminal voltage will get overcharged while the other will be left undercharged. Nice work!

Thanks Rumesh. I have some points that need to ask from you and all. Kindly reply with the detail as you know it.

I have 2 batteries as I mentioned above. One is maintenance free battery that is bought recently and other one is little old which may be around 2 years and it is NOT a maintenance free one. I check it regularly and refill if required. The older one is on left side. As you can see from the images attached, there is always a 0.2-0.4 difference while charging. Also when the vehicle is idle for several days and then at the first start, the left side battery (older one) voltage falls down to 9.4v and the right side one which is the new one falls only to 10.5v. But once charged after a many kilometers run, the older one only falls down to 10.1v when starting again and the right side one (new one) falls around 11v only.

Does this mean, my older battery is running out of it's time that I will be able to save some money for a new battery? What do you think that I can do to make that battery life longer?

Thanks again.

Watchman · February 21, 2013

Well, the batteries on a J44 are in series, so it wont be a equal voltage. If you wanna check if its the battery's fault or just the positioning just swap them two batteries . I would imagine that the first battery would always have a higher charge than the 2nd..

And Does the J44 not come with an amp meter. Our J32 does, its right below the ash tray (though I'm not sure if its OEM or my dad's handy work)

Edited February 21, 2013 by Watchman

harshansenadhir · February 21, 2013

Nice work Nishan,

Well, the batteries on a J44 are in series, so it wont be a equal voltage. If you wanna check if its the battery's fault or just the positioning just swap them two batteries . I would imagine that the first battery would always have a higher charge than the 2nd..
And Does the J44 not come with an amp meter. Our J32 does, its right below the ash tray (though I'm not sure if its OEM or my dad's handy work)

There's no OEM amp meter, must be your dad's handy work The successor of J44, Pajero got a voltage meter.

Rumesh88 · February 21, 2013

Thanks Rumesh. I have some points that need to ask from you and all. Kindly reply with the detail as you know it.

I have 2 batteries as I mentioned above. One is maintenance free battery that is bought recently and other one is little old which may be around 2 years and it is NOT a maintenance free one. I check it regularly and refill if required. The older one is on left side. As you can see from the images attached, there is always a 0.2-0.4 difference while charging. Also when the vehicle is idle for several days and then at the first start, the left side battery (older one) voltage falls down to 9.4v and the right side one which is the new one falls only to 10.5v. But once charged after a many kilometers run, the older one only falls down to 10.1v when starting again and the right side one (new one) falls around 11v only.

Does this mean, my older battery is running out of it's time that I will be able to save some money for a new battery? What do you think that I can do to make that battery life longer?

Thanks again.

If the two batteries are different in both the type and age it is very difficult to get their voltages matched. It is not advisable to mix old batteries with new, particularly an old freely ventilated one with new maintenance free one. Still in your case it is worthwhile to give the old battery a full charge using an offline charger and see if the battery voltages can be reasonably matched. If they remain matched (within 0.2V) for, let's say for next 2-3 months then you can prolong the service life of BOTH batteries by giving an equalization charge once in a couple of months. Otherwise replace (ideally both batteries!)the old battery with a new one (again of the same type as the remaining one if possible) as soon as possible. Edited February 21, 2013 by Rumesh88