I have 3 8G8D MK gel cells and am unsure of the date. They seem to be ok overnight but what is the best way to do a load test?
Another question for you solar guys: what voltages are you set for bulk, absorb, and float for gel cells?
Thanks!
Can you take them to a shop that sells alot of similar batteries,they should be able to test them.
In Tucsun we had a local battery supply company bring their tester to our coach and do the load test there. I think we paid about $150.00. Those 8Ds are heavy.
Similar post a while back...
Power consumption question (http://www.foreforums.com/index.php?topic=34021.msg311773#msg311773)
I drove to a NAPA store, disconnected the grounds and they came out and tested the house batteries for free. Their handheld test equipment printed out the results. They need to know the make and model # of the battery.
I'm familiar with carbon pile load testers, but is this the recommended method to test the amphour capacity of our 8d gel cell house batteries?
If you have upgraded your inverter/charger to a modern one with a battery management system (Magnum, Victron, etc), it can tell you how many amp hours you've used at any given voltage. You can see from that if you're getting the rated life from your batteries. If you have the OEM charging system, probably the Heart system in '99, you won't see that info. I suppose you could use a clamp meter to measure amp hours and a volt meter to accomplish almost the same thing manually.
A carbon pile load tester will work, but you can also use a battery tester such as the OTC 3167 HP. I do not know how to post a link but just Google. They are expensive but useful to have. I have had one for years. Found it to be very accurate.
I have an AutoMeter SB5/2. Found it on eBay for $160. It does a lot of tests.
Test at 3x amp hr rating for 15 seconds. That is like 750 amps for 15 seconds for an 8D.
Victron Blue Solar Charge Controller Specs. Defaults.
They are adjustable by the end user for battery types.
From Victron ...
1.7 Flexible charge algorithm
Fully programmable charge algorithm, and eight preprogrammed algorithms, selectable with a rotary switch.
1.8 Adaptive three step charging
The BlueSolar MPPT Charge Controller is configured for a three step charging process: Bulk – Absorption – Float.
A regular equalization charge can also be programmed: see section 3.8 of this manual.
1.8.1. Bulk
During this stage the controller delivers as much charge current as possible to rapidly recharge the batteries.
1.8.2. Absorption
When the battery voltage reaches the absorption voltage setting, the controller switches to constant voltage mode.
When only shallow discharges occur the absorption time is kept short in order to prevent overcharging of the battery. After a deep discharge the absorption time is automatically increased to make sure that the battery is completely recharged. Additionally, the absorption period is also ended when the charge current decreases to less than 2A.
1.8.3. Float
During this stage, float voltage is applied to the battery to maintain it in a fully charged state.
1.8.4. Equalization
See section 3.8
I was with Scott when he had his batteries tested. I did a write up of it here.
How to test 8D AGMs (http://www.foreforums.com/index.php?topic=31011.msg271364)
see ya
ken
Ken, I responded to your post regarding that test a year ago. Just as I responded to this post. My tester weighs 3 pounds, does not get hot, is simple to use, and test the batteries just as effective as the testers talked about. The draw back is the cost of about $500.
Why don't you turn on the inverter and run the microwave for 1 minute and then turn everything off. If you have a bad battery they will not recover at idle. Then you can disconnect them one at a time and do it again to find THE bad battery. That's load testing.
Our coach has a magnum power pro round gage installed.
Records amps in and out.
We have 675 amp hours capacity nominally. At 12.85 volts with no load for a day.
If you compare the gauges voltage versus amps used the two should match.
If you are at 12.2 volts and show 350 amp hours consumed then the voltage matches the used amp hours.
Easy if you install a gauge.
The other posts here are to use a std load for x amount of hours then measure the resting batteries voltage.
Same idea, the gauge is way easier.
I thought that the load tester that was used, Ken's pics, looked like it was from the Flash Gorden's days. :D